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Voldstedlund CT, Sjøberg KA, Schlabs FL, Sigvardsen CM, Andersen NR, Holst JJ, Hartmann B, Wojtaszewski JFP, Kiens B, McConell GK, Richter EA. Exercise-induced increase in muscle insulin sensitivity in men is amplified when assessed using a meal test. Diabetologia 2024:10.1007/s00125-024-06148-x. [PMID: 38662135 DOI: 10.1007/s00125-024-06148-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 02/26/2024] [Indexed: 04/26/2024]
Abstract
AIMS/HYPOTHESIS Exercise has a profound effect on insulin sensitivity in skeletal muscle. The euglycaemic-hyperinsulinaemic clamp (EHC) is the gold standard for assessment of insulin sensitivity but it does not reflect the hyperglycaemia that occurs after eating a meal. In previous EHC investigations, it has been shown that the interstitial glucose concentration in muscle is decreased to a larger extent in previously exercised muscle than in rested muscle. This suggests that previously exercised muscle may increase its glucose uptake more than rested muscle if glucose supply is increased by hyperglycaemia. Therefore, we hypothesised that the exercise-induced increase in muscle insulin sensitivity would appear greater after eating a meal than previously observed with the EHC. METHODS Ten recreationally active men performed dynamic one-legged knee extensor exercise for 1 h. Following this, both femoral veins and one femoral artery were cannulated. Subsequently, 4 h after exercise, a solid meal followed by two liquid meals were ingested over 1 h and glucose uptake in the two legs was measured for 3 h. Muscle biopsies from both legs were obtained before the meal test and 90 min after the meal test was initiated. Data obtained in previous studies using the EHC (n=106 participants from 13 EHC studies) were used for comparison with the meal-test data obtained in this study. RESULTS Plasma glucose and insulin peaked 45 min after initiation of the meal test. Following the meal test, leg glucose uptake and glucose clearance increased twice as much in the exercised leg than in the rested leg; this difference is twice as big as that observed in previous investigations using EHCs. Glucose uptake in the rested leg plateaued after 15 min, alongside elevated muscle glucose 6-phosphate levels, suggestive of compromised muscle glucose metabolism. In contrast, glucose uptake in the exercised leg plateaued 45 min after initiation of the meal test and there were no signs of compromised glucose metabolism. Phosphorylation of the TBC1 domain family member 4 (TBC1D4; p-TBC1D4Ser704) and glycogen synthase activity were greater in the exercised leg compared with the rested leg. Muscle interstitial glucose concentration increased with ingestion of meals, although it was 16% lower in the exercised leg than in the rested leg. CONCLUSIONS/INTERPRETATION Hyperglycaemia after meal ingestion results in larger differences in muscle glucose uptake between rested and exercised muscle than previously observed during EHCs. These findings indicate that the ability of exercise to increase insulin-stimulated muscle glucose uptake is even greater when evaluated with a meal test than has previously been shown with EHCs.
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Affiliation(s)
- Christian T Voldstedlund
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Kim A Sjøberg
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Farina L Schlabs
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Casper M Sigvardsen
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Nicoline R Andersen
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bolette Hartmann
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen F P Wojtaszewski
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Bente Kiens
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Glenn K McConell
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia.
| | - Erik A Richter
- August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
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Hanson ED, Sakkal S, Bates-Fraser LC, Que S, Cho E, Spielmann G, Kadife E, Violet JA, Battaglini CL, Stoner L, Bartlett DB, McConell GK, Hayes A. Acute exercise induces distinct quantitative and phenotypical T cell profiles in men with prostate cancer. Front Sports Act Living 2023; 5:1173377. [PMID: 37325799 PMCID: PMC10266416 DOI: 10.3389/fspor.2023.1173377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 05/12/2023] [Indexed: 06/17/2023] Open
Abstract
Background Reduced testosterone levels can influence immune system function, particularly T cells. Exercise during cancer reduces treatment-related side effects and provide a stimulus to mobilize and redistribute immune cells. However, it is unclear how conventional and unconventional T cells (UTC) respond to acute exercise in prostate cancer survivors compared to healthy controls. Methods Age-matched prostate cancer survivors on androgen deprivation therapy (ADT) and those without ADT (PCa) along with non-cancer controls (CON) completed ∼45 min of intermittent cycling with 3 min at 60% of peak power interspersed by 1.5 min of rest. Fresh, unstimulated immune cell populations and intracellular perforin were assessed before (baseline), immediately following (0 h), 2 h, and 24 h post-exercise. Results At 0 h, conventional T cell counts increased by 45%-64% with no differences between groups. T cell frequency decreased by -3.5% for CD3+ and -4.5% for CD4+ cells relative to base at 0 h with CD8+ cells experiencing a delayed decrease of -4.5% at 2 h with no group differences. Compared to CON, the frequency of CD8+CD57+ cells was -18.1% lower in ADT. Despite a potential decrease in maturity, ADT increased CD8+perforin+ GMFI. CD3+Vα7.2+CD161+ counts, but not frequencies, increased by 69% post-exercise while CD3+CD56+ cell counts increased by 127% and were preferentially mobilized (+1.7%) immediately following the acute cycling bout. There were no UTC group differences. Cell counts and frequencies returned to baseline by 24 h. Conclusion Following acute exercise, prostate cancer survivors demonstrate normal T cell and UTC responses that were comparable to CON. Independent of exercise, ADT is associated with lower CD8+ cell maturity (CD57) and perforin frequency that suggests a less mature phenotype. However, higher perforin GMFI may attenuate these changes, with the functional implications of this yet to be determined.
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Affiliation(s)
- Erik D. Hanson
- Department of Exercise & Sport Science, University of North Carolina, Chapel Hill, NC, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, United States
- Human Movement Science Curriculum, University of North Carolina, Chapel Hill, NC, United States
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia
| | - Samy Sakkal
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia
| | - Lauren C. Bates-Fraser
- Department of Exercise & Sport Science, University of North Carolina, Chapel Hill, NC, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, United States
- Human Movement Science Curriculum, University of North Carolina, Chapel Hill, NC, United States
| | - Shadney Que
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia
| | - Eunhan Cho
- School of Kinesiology, Louisiana State University, Baton Rouge, LA, United States
| | - Guillaume Spielmann
- School of Kinesiology, Louisiana State University, Baton Rouge, LA, United States
| | - Elif Kadife
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia
| | - John A. Violet
- Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Claudio L. Battaglini
- Department of Exercise & Sport Science, University of North Carolina, Chapel Hill, NC, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, United States
- Human Movement Science Curriculum, University of North Carolina, Chapel Hill, NC, United States
| | - Lee Stoner
- Department of Exercise & Sport Science, University of North Carolina, Chapel Hill, NC, United States
- Human Movement Science Curriculum, University of North Carolina, Chapel Hill, NC, United States
| | - David B. Bartlett
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Glenn K. McConell
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia
| | - Alan Hayes
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia
- Australian Institute for Musculoskeletal Science (AIMSS), Victoria University, Melbourne, VIC, Australia
- Department of Medicine—Western Health, Melbourne Medical School, The University of Melbourne, Melbourne, VIC, Australia
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3
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Genders AJ, Kuang J, Marin EC, Saner NJ, Botella J, Jacques M, McConell GK, Andrade-Souza VA, Chagolla J, Bishop DJ. Exercise does not improve insulin resistance and mitochondrial characteristics together. J Endocrinol 2021; 252:91-105. [PMID: 34783678 DOI: 10.1530/joe-21-0242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 11/12/2021] [Indexed: 11/08/2022]
Abstract
The aim of this study was to investigate the relationship between mitochondrial content and respiratory function and whole-body insulin resistance in high-fat diet (HFD) fed rats. Male Wistar rats were given either a chow diet or an HFD for 12 weeks. After 4 weeks of the dietary intervention, half of the rats in each group began 8 weeks of interval training. In vivo glucose and insulin tolerance were assessed. Mitochondrial respiratory function was assessed in permeabilised soleus and white gastrocnemius (WG) muscles. Mitochondrial content was determined by the measurement of citrate synthase (CS) activity and protein expression of components of the electron transport system (ETS). We found HFD rats had impaired glucose and insulin tolerance but increased mitochondrial respiratory function and increased protein expression of components of the ETS. This was accompanied by an increase in CS activity in WG. Exercise training improved glucose and insulin tolerance in the HFD rats. Mitochondrial respiratory function was increased with exercise training in the chow-fed animals in soleus muscle. This exercise effect was absent in the HFD animals. In conclusion, exercise training improved insulin resistance in HFD rats but without changes in mitochondrial respiratory function and content. The lack of an association between mitochondrial characteristics and whole-body insulin resistance was reinforced by the absence of strong correlations between these measures. Our results suggest that improvements in mitochondrial respiratory function and content are not responsible for improvements in whole-body insulin resistance in HFD rats.
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Affiliation(s)
- Amanda J Genders
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Jujiao Kuang
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Evelyn C Marin
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Nicholas J Saner
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Javier Botella
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Macsue Jacques
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Glenn K McConell
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Victor A Andrade-Souza
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - Javier Chagolla
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
| | - David J Bishop
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, Victoria, Australia
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Atakan MM, Güzel Y, Bulut S, Koşar ŞN, McConell GK, Turnagöl HH. Six high-intensity interval training sessions over 5 days increases maximal oxygen uptake, endurance capacity, and sub-maximal exercise fat oxidation as much as 6 high-intensity interval training sessions over 2 weeks. J Sport Health Sci 2021; 10:478-487. [PMID: 32565243 PMCID: PMC8343121 DOI: 10.1016/j.jshs.2020.06.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/23/2020] [Accepted: 05/16/2020] [Indexed: 05/11/2023]
Abstract
BACKGROUND High-intensity interval training (HIIT) induces similar or even superior adaptations compared to continuous endurance training. Indeed, just 6 HIIT sessions over 2 weeks significantly improves maximal oxygen uptake (VO2max), submaximal exercise fat oxidation, and endurance performance. Whether even faster adaptations can be achieved with HIIT is not known. Thus, we aimed to determine whether 2 sessions of HIIT per day, separated by 3 h, every other day for 5 days (double HIIT (HIIT-D), n = 15) could increase VO2max, submaximal exercise fat oxidation, and endurance capacity as effectively as 6 sessions of HIIT over 2 weeks (single HIIT (HIIT-S), n = 13). METHODS Each training session consisted of 10 × 60 s of cycling at 100% of VO2max interspersed with 75 s of low-intensity cycling at 60 watt (W). Pre- and post-training assessments included VO2max, time to exhaustion at ∼80% of VO2max, and 60-min cycling trials at ∼67% of VO2max. RESULTS Similar increases (p < 0.05) in VO2max (HIIT-D: 7.7% vs. HIIT-S: 6.0%, p > 0.05) and endurance capacity (HIIT-D: 80.1% vs. HIIT-S: 79.2%, p > 0.05) were observed. Submaximal exercise carbohydrate oxidation was reduced in the 2 groups after exercise training (HIIT-D: 9.2%, p = 0.014 vs. HIIT-S: 18.8%, p = 0.012) while submaximal exercise fat oxidation was significantly increased in HIIT-D (15.5%, p = 0.048) but not in HIIT-S (9.3%, p = 0.290). CONCLUSION Six HIIT sessions over 5 days was as effective in increasing VO2max and endurance capacity and was more effective in improving submaximal exercise fat oxidation than 6 HIIT sessions over 2 weeks.
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Affiliation(s)
- Muhammed M Atakan
- Division of Nutrition and Metabolism in Exercise, Faculty of Sport Sciences, Hacettepe University, Ankara 06690, Turkey; Institute for Health and Sport, Victoria University, Melbourne, VIA 3011, Australia
| | - Yasemin Güzel
- Division of Nutrition and Metabolism in Exercise, Faculty of Sport Sciences, Hacettepe University, Ankara 06690, Turkey
| | - Süleyman Bulut
- Division of Nutrition and Metabolism in Exercise, Faculty of Sport Sciences, Hacettepe University, Ankara 06690, Turkey
| | - Şükran N Koşar
- Division of Nutrition and Metabolism in Exercise, Faculty of Sport Sciences, Hacettepe University, Ankara 06690, Turkey
| | - Glenn K McConell
- Institute for Health and Sport, Victoria University, Melbourne, VIA 3011, Australia.
| | - Hüseyin H Turnagöl
- Division of Nutrition and Metabolism in Exercise, Faculty of Sport Sciences, Hacettepe University, Ankara 06690, Turkey.
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McConell GK, Wadley GD, Le Plastrier K, Linden KC. Skeletal muscle AMPK is not activated during 2 h of moderate intensity exercise at ∼65% V ̇ O 2 peak in endurance trained men. J Physiol 2020; 598:3859-3870. [PMID: 32588910 PMCID: PMC7540472 DOI: 10.1113/jp277619] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 06/17/2020] [Indexed: 12/22/2022] Open
Abstract
Key points AMP‐activated protein kinase (AMPK) is considered a major regulator of skeletal muscle metabolism during exercise. However, we previously showed that, although AMPK activity increases by 8–10‐fold during ∼120 min of exercise at ∼65% V˙O2peak in untrained individuals, there is no increase in these individuals after only 10 days of exercise training (longitudinal study). In a cross‐sectional study, we show that there is also a lack of activation of skeletal muscle AMPK during 120 min of cycling exercise at 65% V˙O2peak in endurance‐trained individuals. These findings indicate that AMPK is not an important regulator of exercise metabolism during 120 min of exercise at 65% V˙O2peak in endurance trained men. It is important that more energy is directed towards examining other potential regulators of exercise metabolism.
Abstract AMP‐activated protein kinase (AMPK) is considered a major regulator of skeletal muscle metabolism during exercise. Indeed, AMPK is activated during exercise and activation of AMPK by 5‐aminoimidazole‐4‐carboxyamide‐ribonucleoside (AICAR) increases skeletal muscle glucose uptake and fat oxidation. However, we have previously shown that, although AMPK activity increases by 8–10‐fold during ∼120 min of exercise at ∼65% V˙O2peak in untrained individuals, there is no increase in these individuals after only 10 days of exercise training (longitudinal study). In a cross‐sectional study, we examined whether there is also a lack of activation of skeletal muscle AMPK during 120 min of cycling exercise at 65% V˙O2peak in endurance‐trained individuals. Eleven untrained (UT; V˙O2peak = 37.9 ± 5.6 ml.kg−1 min−1) and seven endurance trained (ET; V˙O2peak = 61.8 ± 2.2 ml.kg−1 min−1) males completed 120 min of cycling exercise at 66 ± 4% V˙O2peak (UT: 100 ± 21 W; ET: 190 ± 15 W). Muscle biopsies were obtained at rest and following 30 and 120 min of exercise. Muscle glycogen was significantly (P < 0.05) higher before exercise in ET and decreased similarly during exercise in the ET and UT individuals. Exercise significantly increased calculated skeletal muscle free AMP content and more so in the UT individuals. Exercise significantly (P < 0.05) increased skeletal muscle AMPK α2 activity (4‐fold), AMPK αThr172 phosphorylation (2‐fold) and ACCβ Ser222 phosphorylation (2‐fold) in the UT individuals but not in the ET individuals. These findings indicate that AMPK is not an important regulator of exercise metabolism during 120 min of exercise at 65% V˙O2peak in endurance trained men. AMP‐activated protein kinase (AMPK) is considered a major regulator of skeletal muscle metabolism during exercise. However, we previously showed that, although AMPK activity increases by 8–10‐fold during ∼120 min of exercise at ∼65% V˙O2peak in untrained individuals, there is no increase in these individuals after only 10 days of exercise training (longitudinal study). In a cross‐sectional study, we show that there is also a lack of activation of skeletal muscle AMPK during 120 min of cycling exercise at 65% V˙O2peak in endurance‐trained individuals. These findings indicate that AMPK is not an important regulator of exercise metabolism during 120 min of exercise at 65% V˙O2peak in endurance trained men. It is important that more energy is directed towards examining other potential regulators of exercise metabolism.
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Affiliation(s)
- Glenn K McConell
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia.,Department of Physiology, University of Melbourne, Melbourne, VIC, Australia
| | - Glenn D Wadley
- Department of Physiology, University of Melbourne, Melbourne, VIC, Australia.,Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | | | - Kelly C Linden
- Department of Physiology, University of Melbourne, Melbourne, VIC, Australia.,Faculty of Science, Charles Sturt University, Albury, NSW, Australia
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Hanson ED, Sakkal S, Que S, Cho E, Spielmann G, Kadife E, Violet JA, Battaglini CL, Stoner L, Bartlett DB, McConell GK, Hayes A. Natural killer cell mobilization and egress following acute exercise in men with prostate cancer. Exp Physiol 2020; 105:1524-1539. [PMID: 32715550 DOI: 10.1113/ep088627] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 06/29/2020] [Indexed: 01/19/2023]
Abstract
NEW FINDINGS What is the central question of this study? What are the characteristics of the NK cell response following acute moderate-intensity aerobic exercise in prostate cancer survivors and is there a relationship between stress hormones and NK cell mobilization? What is the main finding and its importance? NK cell numbers and proportions changed similarly between prostate cancer survivors and controls following acute exercise. Consecutive training sessions can likely be used without adverse effects on the immune system during prostate cancer treatment. ABSTRACT Prostate cancer treatment affects multiple physiological systems, although the immune response during exercise has been minimally investigated. The objective was to characterize the natural killer (NK) cell response following acute exercise in prostate cancer survivors. Prostate cancer survivors on androgen deprivation therapy (ADT) and those without (PCa) along with non-cancer controls (CON) completed a moderate intensity cycling bout. NK cells were phenotyped before and 0, 2 and 24 h after acute exercise using flow cytometry. CD56 total NK cell frequency increased by 6.2% at 0 h (P < 0.001) and decreased by 2.5% at 2 h (P < 0.01) with similar findings in CD56dim cells. NK cell counts also exhibited a biphasic response. Independent of exercise, ADT had intracellular interferon γ (IFNγ) expression that was nearly twofold higher than CON (P < 0.01). PCa perforin expression was reduced by 11.4% (P < 0.05), suggesting these cells may be more prone to degranulation. CD57- NK cells demonstrated increased perforin and IFNγ frequencies after exercise with no change within the CD57+ populations. All NK and leukocyte populations returned to baseline by 24 h. NK cell mobilization and egress with acute exercise appear normal, as cell counts and frequencies in prostate cancer survivors change similarly to CON. However, lower perforin proportions (PCa) and higher IFNγ expression (ADT) may alter NK cytotoxicity and require further investigation. The return of NK cell proportions to resting levels overnight suggests that consecutive training sessions can be used without adverse effects on the immune system during prostate cancer treatment.
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Affiliation(s)
- Erik D Hanson
- Department of Exercise & Sport Science, University of North Carolina, Chapel Hill, NC, USA.,Institute for Health and Sport, Victoria University, Melbourne, Vic, Australia
| | - Samy Sakkal
- Institute for Health and Sport, Victoria University, Melbourne, Vic, Australia
| | - Shadney Que
- Institute for Health and Sport, Victoria University, Melbourne, Vic, Australia
| | - Eunhan Cho
- School of Kinesiology, Louisiana State University, Baton Rouge, LA, USA
| | | | - Elif Kadife
- Institute for Health and Sport, Victoria University, Melbourne, Vic, Australia
| | - John A Violet
- Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Vic, Australia
| | - Claudio L Battaglini
- Department of Exercise & Sport Science, University of North Carolina, Chapel Hill, NC, USA
| | - Lee Stoner
- Department of Exercise & Sport Science, University of North Carolina, Chapel Hill, NC, USA
| | - David B Bartlett
- Division of Medical Oncology, Duke Cancer Institute, Duke University, Durham, NC, USA
| | - Glenn K McConell
- Institute for Health and Sport, Victoria University, Melbourne, Vic, Australia
| | - Alan Hayes
- Institute for Health and Sport, Victoria University, Melbourne, Vic, Australia.,Australian Institute for Musculoskeletal Science (AIMSS), Victoria University, Melbourne, Vic, Australia.,Department of Medicine, Western Health, Melbourne Medical School, University of Melbourne, Melbourne, Vic, Australia
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7
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Falcão-Tebas F, Marin EC, Kuang J, Bishop DJ, McConell GK. Maternal exercise attenuates the lower skeletal muscle glucose uptake and insulin secretion caused by paternal obesity in female adult rat offspring. J Physiol 2020; 598:4251-4270. [PMID: 32539156 PMCID: PMC7586952 DOI: 10.1113/jp279582] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 06/02/2020] [Indexed: 12/15/2022] Open
Abstract
KEY POINTS Paternal obesity negatively influences metabolic outcomes in adult rat offspring. Maternal voluntary physical activity has previously been reported to improve glucose metabolism in adult rat offspring sired by healthy fathers. Here, we investigated whether a structured programme of maternal exercise training before and during gestation can attenuate the negative impacts that paternal obesity has on insulin sensitivity and secretion in female adult offspring. Exercise before and during pregnancy normalised the lower insulin sensitivity in skeletal muscle and the lower insulin secretion observed in female offspring sired by obese fathers. This paper presents a feasible, low-cost and translatable intervention strategy that can be applied perinatally to support multifactor interventions to break the cycle of metabolic dysfunction caused by paternal obesity. ABSTRACT We investigated whether maternal exercise before and during gestation could attenuate the negative metabolic effects of paternal high-fat diet-induced obesity in female adult rat offspring. Fathers consumed a normal chow or high-fat diet before mating. Mothers exercised on a treadmill before and during gestation or remained sedentary. In adulthood, female offspring were assessed using intraperitoneal insulin and glucose tolerance tests (IPITT and IPGTT, respectively), pancreatic morphology, ex vivo skeletal muscle insulin-stimulated glucose uptake and mitochondrial respiratory function. Paternal obesity impaired whole-body and skeletal muscle insulin sensitivity and insulin secretion in adult offspring. Maternal exercise attenuated the lower insulin-stimulated glucose uptake in offspring sired by obese fathers but distal insulin signalling components (p-AKT Thr308 and Ser473, p-TBC1D4 Thr642 and GLUT4) remained unchanged (P > 0.05). Maternal exercise increased citrate synthase activity only in offspring sired by obese fathers. Maternal exercise also reversed the lower insulin secretion in vivo observed in offspring of obese fathers, probably due to an attenuation of the decrease in pancreatic beta cell mass. In summary, maternal exercise before and during pregnancy in rats attenuated skeletal muscle insulin resistance and attenuated the decrease in pancreatic beta cell mass and insulin secretion observed in the female offspring of obese fathers.
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Affiliation(s)
- Filippe Falcão-Tebas
- Institute for Health and Sport (IHES), Victoria University, Melbourne, Australia.,The Ritchie Centre, Hudson Institute of Medical Research, and Department of Obstetrics and Gynaecology, Monash University, Melbourne, Australia
| | - Evelyn C Marin
- Institute for Health and Sport (IHES), Victoria University, Melbourne, Australia.,Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Australia
| | - Jujiao Kuang
- Institute for Health and Sport (IHES), Victoria University, Melbourne, Australia
| | - David J Bishop
- Institute for Health and Sport (IHES), Victoria University, Melbourne, Australia
| | - Glenn K McConell
- Institute for Health and Sport (IHES), Victoria University, Melbourne, Australia.,College of Health and Biomedicine, Victoria University, Melbourne, Australia
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8
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Affiliation(s)
- Glenn K McConell
- Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia
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9
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Keske MA, Barrett EJ, Lindner JR, Richter EA, Liu Z, McConell GK, Askew CD, Serné EH, Premilovac D, Richards SM, Rattigan S, Eringa EC. Perfusion controls muscle glucose uptake by altering the rate of glucose dispersion in vivo. Am J Physiol Endocrinol Metab 2020; 318:E311-E312. [PMID: 32068465 DOI: 10.1152/ajpendo.00430.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Michelle A Keske
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Geelong, Victoria, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Eugene J Barrett
- Division of Endocrinology, Department of Medicine, University of Virginia, School of Medicine, Charlottesville, Virginia
| | | | - Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - Zhenqi Liu
- Division of Endocrinology, Department of Medicine, University of Virginia, School of Medicine, Charlottesville, Virginia
| | - Glenn K McConell
- Institute for Health and Sport (IHeS), Victoria University, Melbourne, Victoria, Australia
| | - Christopher D Askew
- VasoActive Research Group, Sunshine Coast Health Institute (SCHI), University of the Sunshine Coast, Birtinya, Queensland, Australia
| | - Erik H Serné
- Department of Internal Medicine, Amsterdam University Medical Center, VU University Medical Centre, Amsterdam, The Netherlands
| | - Dino Premilovac
- School of Medicine, University of Tasmania, Hobart, Tasmania, Australia
| | | | - Stephen Rattigan
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Etto C Eringa
- Department of Physiology, Amsterdam University Medical Center, VU University Medical Centre, Amsterdam, The Netherlands
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McConell GK, Sjøberg KA, Ceutz F, Gliemann L, Nyberg M, Hellsten Y, Frøsig C, Kiens B, Wojtaszewski JFP, Richter EA. Insulin-induced membrane permeability to glucose in human muscles at rest and following exercise. J Physiol 2020; 598:303-315. [PMID: 31696935 DOI: 10.1113/jp278600] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 11/04/2019] [Indexed: 12/18/2022] Open
Abstract
KEY POINTS Increased insulin action is an important component of the health benefits of exercise, but its regulation is complex and not fully elucidated. Previous studies of insulin-stimulated GLUT4 translocation to the skeletal muscle membrane found insufficient increases to explain the increases in glucose uptake. By determination of leg glucose uptake and interstitial muscle glucose concentration, insulin-induced muscle membrane permeability to glucose was calculated 4 h after one-legged knee-extensor exercise during a submaximal euglycaemic-hyperinsulinaemic clamp. It was found that during submaximal insulin stimulation, muscle membrane permeability to glucose in humans increases twice as much in previously exercised vs. rested muscle and outstrips the supply of glucose, which then becomes limiting for glucose uptake. This methodology can now be employed to determine muscle membrane permeability to glucose in people with diabetes, who have reduced insulin action, and in principle can also be used to determine membrane permeability to other substrates or metabolites. ABSTRACT Increased insulin action is an important component of the health benefits of exercise, but the regulation of insulin action in vivo is complex and not fully elucidated. Previously determined increases in skeletal muscle insulin-stimulated GLUT4 translocation are inconsistent and mostly cannot explain the increases in insulin action in humans. Here we used leg glucose uptake (LGU) and interstitial muscle glucose concentration to calculate insulin-induced muscle membrane permeability to glucose, a variable not previously possible to quantify in humans. Muscle membrane permeability to glucose, measured 4 h after one-legged knee-extensor exercise, increased ∼17-fold during a submaximal euglycaemic-hyperinsulinaemic clamp in rested muscle (R) and ∼36-fold in exercised muscle (EX). Femoral arterial infusion of NG -monomethyl l-arginine acetate or ATP decreased and increased, respectively, leg blood flow (LBF) in both legs but did not affect membrane glucose permeability. Decreasing LBF reduced interstitial glucose concentrations to ∼2 mM in the exercised but only to ∼3.5 mM in non-exercised muscle and abrogated the augmented effect of insulin on LGU in the EX leg. Increasing LBF by ATP infusion increased LGU in both legs with uptake higher in the EX leg. We conclude that it is possible to measure functional muscle membrane permeability to glucose in humans and it increases twice as much in exercised vs. rested muscle during submaximal insulin stimulation. We also show that muscle perfusion is an important regulator of muscle glucose uptake when membrane permeability to glucose is high and we show that the capillary wall can be a significant barrier for glucose transport.
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Affiliation(s)
- Glenn K McConell
- Institute for Health and Sport, Victoria University, Footscray, Melbourne, Australia
| | - Kim A Sjøberg
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Frederik Ceutz
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Lasse Gliemann
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Michael Nyberg
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Ylva Hellsten
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Christian Frøsig
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Bente Kiens
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen F P Wojtaszewski
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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11
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McConell GK, Sjøberg KA, Ceutz F, Gliemann L, Nyberg MP, Hellsten Y, Frøsig C, Kiens B, Wojtaszewski JF, Richter EA. Muscle membrane permeability to glucose and blood flow explain increased insulin sensitivity in muscle after exercise. Obes Res Clin Pract 2019. [DOI: 10.1016/j.orcp.2018.11.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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12
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Falcão-Tebas F, Kuang J, Arceri C, Kerris JP, Andrikopoulos S, Marin EC, McConell GK. Four weeks of exercise early in life reprograms adult skeletal muscle insulin resistance caused by a paternal high-fat diet. J Physiol 2018; 597:121-136. [PMID: 30406963 DOI: 10.1113/jp276386] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 10/05/2018] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS A paternal high-fat diet/obesity before mating can negatively influence the metabolism of offspring. Exercise only early in life has a remarkable effect with respect to reprogramming adult rat offspring exposed to detrimental insults before conception. Exercise only early in life normalized adult whole body and muscle insulin resistance as a result of having a high-fat fed/obese father. Unlike the effects on the muscle, early exercise did not normalize the reduced adult pancreatic beta cell mass as a result of having a high-fat fed/obese father. Early-life exercise training may be able to reprogram an individual whose father was obese, inducing long-lasting beneficial effects on health. ABSTRACT A paternal high-fat diet (HFD) impairs female rat offspring glucose tolerance, pancreatic morphology and insulin secretion. We examined whether only 4 weeks of exercise early in life could reprogram these negative effects. Male Sprague-Dawley rats consumed a HFD for 10 weeks before mating with chow-fed dams. Female offspring remained sedentary or performed moderate intensity treadmill exercise (5 days week-1 , 60 min day-1 , 20 m min-1 ) from 5 to 9 weeks of age. Paternal HFD impaired (P < 0.05) adult offspring whole body insulin sensitivity (i.p. insulin sensitivity test), as well as skeletal muscle ex vivo insulin sensitivity and TBC1D4 phosphorylation. It also lowered β-cell mass and reduced in vivo insulin secretion in response to an i.p. glucose tolerance test. Early-life exercise in offspring reprogrammed the negative effects of a paternal HFD on whole body insulin sensitivity, skeletal muscle ex vivo insulin-stimulated glucose uptake and TBC1D4 phosphorylation and also increased glucose transporter 4 protein. However, early exercise did not normalize the reduced pancreatic β-cell mass or insulin secretion. In conclusion, only 4 weeks of exercise early in life in female rat offspring reprograms reductions in insulin sensitivity in adulthood caused by a paternal HFD without affecting pancreatic β-cell mass or insulin secretion.
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Affiliation(s)
- Filippe Falcão-Tebas
- Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia.,The Ritchie Centre, Hudson Institute of Medical Research and Department of Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
| | - Jujiao Kuang
- Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia
| | - Chelsea Arceri
- Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia
| | - Jarrod P Kerris
- Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia
| | - Sofianos Andrikopoulos
- Department of Medicine, Austin Hospital, The University of Melbourne, Melbourne, VIC, Australia
| | - Evelyn C Marin
- Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia.,Department of Medicine, Austin Hospital, The University of Melbourne, Melbourne, VIC, Australia
| | - Glenn K McConell
- Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia.,College of Health and Biomedicine, Victoria University, Melbourne, VIC, Australia
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Trewin AJ, Parker L, Shaw CS, Hiam DS, Garnham A, Levinger I, McConell GK, Stepto NK. Acute HIIE elicits similar changes in human skeletal muscle mitochondrial H2O2 release, respiration, and cell signaling as endurance exercise even with less work. Am J Physiol Regul Integr Comp Physiol 2018; 315:R1003-R1016. [DOI: 10.1152/ajpregu.00096.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
It remains unclear whether high-intensity interval exercise (HIIE) elicits distinct molecular responses to traditional endurance exercise relative to the total work performed. We aimed to investigate the influence of exercise intensity on acute perturbations to skeletal muscle mitochondrial function (respiration and reactive oxygen species) and metabolic and redox signaling responses. In a randomized, repeated measures crossover design, eight recreationally active individuals (24 ± 5 yr; V̇o2peak: 48 ± 11 ml·kg−1·min−1) undertook continuous moderate-intensity [CMIE: 30 min, 50% peak power output (PPO)], high-intensity interval (HIIE: 5 × 4 min, 75% PPO, work matched to CMIE), and low-volume sprint interval (SIE: 4 × 30 s) exercise, ≥7 days apart. Each session included muscle biopsies at baseline, immediately, and 3 h postexercise for high-resolution mitochondrial respirometry ( Jo2) and H2O2 emission ( Jh2o2) and gene and protein expression analysis. Immediately postexercise and irrespective of protocol, Jo2 increased during complex I + II leak/state 4 respiration but Jh2o2 decreased ( P < 0.05). AMP-activated protein kinase and acetyl co-A carboxylase phosphorylation increased ~1.5 and 2.5-fold respectively, while thioredoxin-reductase-1 protein abundance was ~35% lower after CMIE vs. SIE ( P < 0.05). At 3 h postexercise, regardless of protocol, Jo2 was lower during both ADP-stimulated state 3 OXPHOS and uncoupled respiration ( P < 0.05) but Jh2o2 trended higher ( P < 0.08) and PPARGC1A mRNA increased ~13-fold, and peroxiredoxin-1 protein decreased ~35%. In conclusion, intermittent exercise performed at high intensities has similar dynamic effects on muscle mitochondrial function compared with endurance exercise, irrespective of whether total workload is matched. This suggests exercise prescription can accommodate individual preferences while generating comparable molecular signals known to promote beneficial metabolic adaptations.
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Affiliation(s)
- Adam J. Trewin
- Institute for Health and Sport, Victoria University, Melbourne, Australia
| | - Lewan Parker
- Institute for Health and Sport, Victoria University, Melbourne, Australia
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Victoria, Australia
| | - Christopher S. Shaw
- Institute for Health and Sport, Victoria University, Melbourne, Australia
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Victoria, Australia
| | - Danielle S. Hiam
- Institute for Health and Sport, Victoria University, Melbourne, Australia
| | - Andrew Garnham
- Institute for Health and Sport, Victoria University, Melbourne, Australia
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Victoria, Australia
| | - Itamar Levinger
- Institute for Health and Sport, Victoria University, Melbourne, Australia
- Australian Institute for Musculoskeletal Science, Department of Medicine, Western Health, Melbourne Medical School, The University of Melbourne, Melbourne, Victoria, Australia
| | - Glenn K. McConell
- Institute for Health and Sport, Victoria University, Melbourne, Australia
| | - Nigel K. Stepto
- Institute for Health and Sport, Victoria University, Melbourne, Australia
- Australian Institute for Musculoskeletal Science, Department of Medicine, Western Health, Melbourne Medical School, The University of Melbourne, Melbourne, Victoria, Australia
- Monash Centre of Health Research and Implementation, School of Public Health and Preventative Medicine, Monash University, Clayton, Victoria, Australia
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14
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Kerris JP, Betik AC, Li J, McConell GK. Passive stretch regulates skeletal muscle glucose uptake independent of nitric oxide synthase. J Appl Physiol (1985) 2018; 126:239-245. [PMID: 30236052 DOI: 10.1152/japplphysiol.00368.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle contraction increases glucose uptake via an insulin-independent mechanism. Signaling pathways arising from mechanical strain are activated during muscle contractions, and mechanical strain in the form of passive stretching stimulates glucose uptake. However, the exact mechanisms regulating stretch-stimulated glucose uptake are not known. Since nitric oxide synthase (NOS) has been implicated in the regulation of glucose uptake during ex vivo and in situ muscle contractions and during exercise, and NO is increased with stretch, we examined whether the increase in muscle glucose uptake during stretching involves NOS. We passively stretched isolated extensor digitorum longus muscles (15 min at ~100-130 mN) from control mice and mice lacking either neuronal NOSµ (nNOSµ) or endothelial NOS (eNOS) isoforms, as well as used pharmacological inhibitors of NOS. Stretch significantly increased muscle glucose uptake appoximately twofold ( P < 0.05), and this was unaffected by the presence of the NOS inhibitors NG-monomethyl-l-arginine (100 µM) or NG-nitro-l-arginine methyl ester (100 µM). Similarly, stretch-stimulated glucose uptake was not attenuated by deletion of either eNOS or nNOSµ isoforms. Furthermore, stretching failed to increase skeletal muscle NOS enzymatic activity above resting levels. These data clearly demonstrate that stretch-stimulated skeletal muscle glucose uptake is not dependent on NOS. NEW & NOTEWORTHY Passive stretching is known to activate muscle glucose uptake through mechanisms that partially overlap with contraction. We report that genetic knockout of endothelial nitric oxide synthase (NOS) or neuronal NOS or pharmacological NOS inhibition does not affect stretch-stimulated glucose uptake. Passive stretch failed to increase NOS activity above resting levels. This information is important for the study of signaling pathways that regulate stretch-stimulated glucose uptake and indicate that NOS should be excluded as a potential signaling factor in this regard.
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Affiliation(s)
- Jarrod P Kerris
- Institute for Health and Sport, Victoria University , Melbourne , Australia.,College of Sport and Exercise Science, Victoria University , Melbourne , Australia
| | - Andrew C Betik
- Institute for Health and Sport, Victoria University , Melbourne , Australia.,College of Health and Biomedicine, Victoria University , Melbourne , Australia
| | - Jinhua Li
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University , Clayton , Australia
| | - Glenn K McConell
- Institute for Health and Sport, Victoria University , Melbourne , Australia.,College of Sport and Exercise Science, Victoria University , Melbourne , Australia
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15
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Hanson ED, Sakkal S, Evans WS, Violet JA, Battaglini CL, McConell GK, Hayes A. Altered stress hormone response following acute exercise during prostate cancer treatment. Scand J Med Sci Sports 2018; 28:1925-1933. [PMID: 29668082 DOI: 10.1111/sms.13199] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2018] [Indexed: 02/06/2023]
Abstract
Exercise training reduces the side effects of cancer treatments; however, the stress hormone response to acute exercise during prostate cancer (PCa) treatment is unclear. The study purpose was to examine the effects of acute exercise on circulating cortisol, epinephrine (Epi), and norepinephrine (NE) concentrations during PCa treatment with and without androgen deprivation therapy (ADT). Men with PCa (n = 11), with PCa on ADT (n = 11), and with non-cancer controls (n = 8) had blood samples for stress hormones collected before and immediately (0 hour), 2 hours, and 24 hours after 45 minutes of intermittent cycling at 60% of peak wattage. NE increased by 385% (P < .001) at 0 hour and remained elevated at 2 hours (P < .05) with no group differences. Overall, cortisol significantly increased at 0 hour (36%, P < .012) and then significantly decreased below baseline at 2 hours (-24%, P < .001) before returning to resting levels at 24 hours. Cortisol levels during ADT were 32% lower than PCa (P = .006) with no differences vs controls. Epi increased immediately after exercise more in controls (817%, P < .001) than with ADT (700%) and PCa (333%) patients, and both cancer groups' absolute levels were attenuated relative to controls (ADT: -54%, PCa: -52%, P = .004). Compared with age-matched controls, PCa and ADT patients exhibited similar stress hormone responses with acute exercise for NE and cortisol but an attenuated EPI response that suggests altered adrenal function. Future studies should examine the physical stress of multiple exercise bouts to verify these findings and to explore the functional hormonal effects, such as immune and metabolic responses, during cancer treatment.
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Affiliation(s)
- E D Hanson
- Department of Exercise & Sport Science, University of North Carolina, Chapel Hill, NC, USA.,Institute for Health and Sport, Victoria University, Melbourne, Vic., Australia
| | - S Sakkal
- Institute for Health and Sport, Victoria University, Melbourne, Vic., Australia
| | - W S Evans
- Department of Exercise & Sport Science, University of North Carolina, Chapel Hill, NC, USA
| | - J A Violet
- Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Vic., Australia
| | - C L Battaglini
- Department of Exercise & Sport Science, University of North Carolina, Chapel Hill, NC, USA
| | - G K McConell
- Institute for Health and Sport, Victoria University, Melbourne, Vic., Australia
| | - A Hayes
- Institute for Health and Sport, Victoria University, Melbourne, Vic., Australia.,Australian Institute for Musculoskeletal Science, Victoria University, Melbourne, Vic., Australia.,Department of Medicine - Western Health, Melbourne Medical School, The University of Melbourne, Melbourne, Vic., Australia
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16
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Zhang X, Hiam D, Hong YH, Zulli A, Hayes A, Rattigan S, McConell GK. Nitric oxide is required for the insulin sensitizing effects of contraction in mouse skeletal muscle. J Physiol 2017; 595:7427-7439. [PMID: 29071734 DOI: 10.1113/jp275133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 10/18/2017] [Indexed: 01/15/2023] Open
Abstract
KEY POINTS People with insulin resistance or type 2 diabetes can substantially increase their skeletal muscle glucose uptake during exercise and insulin sensitivity after exercise. Skeletal muscle nitric oxide (NO) is important for glucose uptake during exercise, although how prior exercise increases insulin sensitivity is unclear. In the present study, we examined whether NO is necessary for normal increases in skeletal muscle insulin sensitivity after contraction ex vivo in mouse muscle. The present study uncovers, for the first time, a novel role for NO in the insulin sensitizing effects of ex vivo contraction, which is independent of blood flow. ABSTRACT The factors regulating the increase in skeletal muscle insulin sensitivity after exercise are unclear. We examined whether nitric oxide (NO) is required for the increase in insulin sensitivity after ex vivo contractions. Isolated C57BL/6J mouse EDL muscles were contracted for 10 min or remained at rest (basal) with or without the NO synthase (NOS) inhibition (NG -monomethyl-l-arginine; l-NMMA; 100 μm). Then, 3.5 h post contraction/basal, muscles were exposed to saline or insulin (120 μU ml-1 ) with or without l-NMMA during the last 30 min. l-NMMA had no effect on basal skeletal muscle glucose uptake. The increase in muscle glucose uptake with insulin (57%) was significantly (P < 0.05) greater after prior contraction (140% increase). NOS inhibition during the contractions had no effect on this insulin-sensitizing effect of contraction, whereas NOS inhibition during insulin prevented the increase in skeletal muscle insulin sensitivity post-contraction. Soluble guanylate cyclase inhibition, protein kinase G (PKG) inhibition or cyclic nucleotide phosphodiesterase inhibition each had no effect on the insulin-sensitizing effect of prior contraction. In conclusion, NO is required for increases in insulin sensitivity several hours after contraction of mouse skeletal muscle via a cGMP/PKG independent pathway.
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Affiliation(s)
- Xinmei Zhang
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia.,School of Health and Biomedical Sciences, RMIT University, Melbourne, VIC, Australia
| | - Danielle Hiam
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia
| | - Yet-Hoi Hong
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia
| | - Anthony Zulli
- College of Health and Biomedicine, Victoria University, Melbourne, VIC, Australia
| | - Alan Hayes
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia.,College of Health and Biomedicine, Victoria University, Melbourne, VIC, Australia
| | - Stephen Rattigan
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Glenn K McConell
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia.,College of Health and Biomedicine, Victoria University, Melbourne, VIC, Australia
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17
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Trewin AJ, Levinger I, Parker L, Shaw CS, Serpiello FR, Anderson MJ, McConell GK, Hare DL, Stepto NK. Acute exercise alters skeletal muscle mitochondrial respiration and H2O2 emission in response to hyperinsulinemic-euglycemic clamp in middle-aged obese men. PLoS One 2017; 12:e0188421. [PMID: 29161316 PMCID: PMC5697830 DOI: 10.1371/journal.pone.0188421] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 11/07/2017] [Indexed: 12/16/2022] Open
Abstract
Obesity, sedentary lifestyle and aging are associated with mitochondrial dysfunction and impaired insulin sensitivity. Acute exercise increases insulin sensitivity in skeletal muscle; however, whether mitochondria are involved in these processes remains unclear. The aim of this study was to investigate the effects of insulin stimulation at rest and after acute exercise on skeletal muscle mitochondrial respiratory function (JO2) and hydrogen peroxide emission (JH2O2), and the associations with insulin sensitivity in obese, sedentary men. Nine men (means ± SD: 57 ± 6 years; BMI 33 ± 5 kg.m2) underwent hyperinsulinemic-euglycemic clamps in two separate trials 1–3 weeks apart: one under resting conditions, and another 1 hour after high-intensity exercise (4x4 min cycling at 95% HRpeak). Muscle biopsies were obtained at baseline, and pre/post clamp to measure JO2 with high-resolution respirometry and JH2O2 via Amplex UltraRed from permeabilized fibers. Post-exercise, both JO2 and JH2O2 during ADP stimulated state-3/OXPHOS respiration were lower compared to baseline (P<0.05), but not after subsequent insulin stimulation. JH2O2 was lower post-exercise and after subsequent insulin stimulation compared to insulin stimulation in the rest trial during succinate supported state-4/leak respiration (P<0.05). In contrast, JH2O2 increased during complex-I supported leak respiration with insulin after exercise compared with resting conditions (P<0.05). Resting insulin sensitivity and JH2O2 during complex-I leak respiration were positively correlated (r = 0.77, P<0.05). We conclude that in obese, older and sedentary men, acute exercise modifies skeletal muscle mitochondrial respiration and H2O2 emission responses to hyperinsulinemia in a respiratory state-specific manner, which may have implications for metabolic diseases involving insulin resistance.
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Affiliation(s)
- Adam J. Trewin
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
| | - Itamar Levinger
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
- Australian Institute for Musculoskeletal Science (AIMSS), Victoria University, St. Albans, Australia
| | - Lewan Parker
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Christopher S. Shaw
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Fabio R. Serpiello
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
| | - Mitchell J. Anderson
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
| | - Glenn K. McConell
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
| | - David L. Hare
- University of Melbourne, and Department of Cardiology, Austin Health, Melbourne, Australia
| | - Nigel K. Stepto
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
- Australian Institute for Musculoskeletal Science (AIMSS), Victoria University, St. Albans, Australia
- Monash Centre for Health Research and Implementation (MCHRI), Monash University and Monash Health, Clayton, Australia
- * E-mail:
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Sjøberg KA, Frøsig C, Kjøbsted R, Sylow L, Kleinert M, Betik AC, Shaw CS, Kiens B, Wojtaszewski JFP, Rattigan S, Richter EA, McConell GK. Exercise Increases Human Skeletal Muscle Insulin Sensitivity via Coordinated Increases in Microvascular Perfusion and Molecular Signaling. Diabetes 2017; 66:1501-1510. [PMID: 28292969 DOI: 10.2337/db16-1327] [Citation(s) in RCA: 105] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 03/08/2017] [Indexed: 11/13/2022]
Abstract
Insulin resistance is a major health risk, and although exercise clearly improves skeletal muscle insulin sensitivity, the mechanisms are unclear. Here we show that initiation of a euglycemic-hyperinsulinemic clamp 4 h after single-legged exercise in humans increased microvascular perfusion (determined by contrast-enhanced ultrasound) by 65% in the exercised leg and 25% in the rested leg (P < 0.05) and that leg glucose uptake increased 50% more (P < 0.05) in the exercised leg than in the rested leg. Importantly, infusion of the nitric oxide synthase inhibitor l-NG-monomethyl-l-arginine acetate (l-NMMA) into both femoral arteries reversed the insulin-stimulated increase in microvascular perfusion in both legs and abrogated the greater glucose uptake in the exercised compared with the rested leg. Skeletal muscle phosphorylation of TBC1D4 Ser318 and Ser704 and glycogen synthase activity were greater in the exercised leg before insulin and increased similarly in both legs during the clamp, and l-NMMA had no effect on these insulin-stimulated signaling pathways. Therefore, acute exercise increases insulin sensitivity of muscle by a coordinated increase in insulin-stimulated microvascular perfusion and molecular signaling at the level of TBC1D4 and glycogen synthase in muscle. This secures improved glucose delivery on the one hand and increased ability to take up and dispose of the delivered glucose on the other hand.
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Affiliation(s)
- Kim A Sjøberg
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - Christian Frøsig
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - Rasmus Kjøbsted
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - Lykke Sylow
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - Maximilian Kleinert
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - Andrew C Betik
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
| | - Christopher S Shaw
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia
- Institute for Physical Activity and Nutrition, Deakin University, Geelong, Victoria, Australia
| | - Bente Kiens
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - Jørgen F P Wojtaszewski
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - Stephen Rattigan
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia
| | - Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - Glenn K McConell
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
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19
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Hanson ED, Sakkal S, Evans WS, Violet JA, McConell GK, Hayes A. Stress Hormone Response To Acute Aerobic Exercise During Prostate Cancer Treatment. Med Sci Sports Exerc 2017. [DOI: 10.1249/01.mss.0000517783.10050.3e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Timpani CA, Trewin AJ, Stojanovska V, Robinson A, Goodman CA, Nurgali K, Betik AC, Stepto N, Hayes A, McConell GK, Rybalka E. Attempting to Compensate for Reduced Neuronal Nitric Oxide Synthase Protein with Nitrate Supplementation Cannot Overcome Metabolic Dysfunction but Rather Has Detrimental Effects in Dystrophin-Deficient mdx Muscle. Neurotherapeutics 2017; 14:429-446. [PMID: 27921261 PMCID: PMC5398978 DOI: 10.1007/s13311-016-0494-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Duchenne muscular dystrophy arises from the loss of dystrophin and is characterized by calcium dysregulation, muscular atrophy, and metabolic dysfunction. The secondary reduction of neuronal nitric oxide synthase (nNOS) from the sarcolemma reduces NO production and bioavailability. As NO modulates glucose uptake, metabolism, and mitochondrial bioenergetics, we investigated whether an 8-week nitrate supplementation regimen could overcome metabolic dysfunction in the mdx mouse. Dystrophin-positive control (C57BL/10) and dystrophin-deficient mdx mice were supplemented with sodium nitrate (85 mg/l) in drinking water. Following the supplementation period, extensor digitorum longus and soleus were excised and radioactive glucose uptake was measured at rest (basal) and during contraction. Gastrocnemius was excised and mitochondrial respiration was measured using the Oroboros Oxygraph. Tibialis anterior was analyzed immunohistochemically for the presence of dystrophin, nNOS, nitrotyrosine, IgG and CD45+ cells, and histologically to assess areas of damage and regeneration. Glucose uptake in the basal and contracting states was normal in unsupplemented mdx muscles but was reduced following nitrate supplementation in mdx muscles only. The mitochondrial utilization of substrates was also impaired in mdx gastrocnemius during phosphorylating and maximal uncoupled respiration, and nitrate could not improve respiration in mdx muscle. Although nitrate supplementation reduced mitochondrial hydrogen peroxide emission, it induced mitochondrial uncoupling in red gastrocnemius, increased muscle fiber peroxynitrite (nitrotyrosine), and promoted skeletal muscle damage. Our novel data suggest that despite lower nNOS protein expression and likely lower NO production in mdx muscle, enhancing NO production with nitrate supplementation in these mice has detrimental effects on skeletal muscle. This may have important relevance for those with DMD.
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Affiliation(s)
- Cara A Timpani
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
| | - Adam J Trewin
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia
| | - Vanesa Stojanovska
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
| | - Ainsley Robinson
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
| | - Craig A Goodman
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia
- Australian Institute of Musculoskeletal Science (AIMSS), Western Health, Melbourne, Victoria, 3021, Australia
| | - Kulmira Nurgali
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
| | - Andrew C Betik
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia
| | - Nigel Stepto
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia
| | - Alan Hayes
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia
- Australian Institute of Musculoskeletal Science (AIMSS), Western Health, Melbourne, Victoria, 3021, Australia
| | - Glenn K McConell
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia
- Australian Institute of Musculoskeletal Science (AIMSS), Western Health, Melbourne, Victoria, 3021, Australia
| | - Emma Rybalka
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia.
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia.
- Australian Institute of Musculoskeletal Science (AIMSS), Western Health, Melbourne, Victoria, 3021, Australia.
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Lee-Young RS, Hoffman NJ, Murphy KT, Henstridge DC, Samocha-Bonet D, Siebel AL, Iliades P, Zivanovic B, Hong YH, Colgan TD, Kraakman MJ, Bruce CR, Gregorevic P, McConell GK, Lynch GS, Drummond GR, Kingwell BA, Greenfield JR, Febbraio MA. Glucose-6-phosphate dehydrogenase contributes to the regulation of glucose uptake in skeletal muscle. Mol Metab 2016; 5:1083-1091. [PMID: 27818934 PMCID: PMC5081409 DOI: 10.1016/j.molmet.2016.09.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 08/29/2016] [Accepted: 09/05/2016] [Indexed: 12/25/2022] Open
Abstract
Objective The development of skeletal muscle insulin resistance is an early physiological defect, yet the intracellular mechanisms accounting for this metabolic defect remained unresolved. Here, we have examined the role of glucose-6-phosphate dehydrogenase (G6PDH) activity in the pathogenesis of insulin resistance in skeletal muscle. Methods Multiple mouse disease states exhibiting insulin resistance and glucose intolerance, as well as obese humans defined as insulin-sensitive, insulin-resistant, or pre-diabetic, were examined. Results We identified increased glucose-6-phosphate dehydrogenase (G6PDH) activity as a common intracellular adaptation that occurs in parallel with the induction of insulin resistance in skeletal muscle and is present across animal and human disease states with an underlying pathology of insulin resistance and glucose intolerance. We observed an inverse association between G6PDH activity and nitric oxide synthase (NOS) activity and show that increasing NOS activity via the skeletal muscle specific neuronal (n)NOSμ partially suppresses G6PDH activity in skeletal muscle cells. Furthermore, attenuation of G6PDH activity in skeletal muscle cells via (a) increased nNOSμ/NOS activity, (b) pharmacological G6PDH inhibition, or (c) genetic G6PDH inhibition increases insulin-independent glucose uptake. Conclusions We have identified a novel, previously unrecognized role for G6PDH in the regulation of skeletal muscle glucose metabolism. Defective skeletal muscle G6PDH activity in multiple insulin resistant animal models. Demonstration of defective skeletal muscle G6PDH activity in pre-diabetic individuals. Identification of nNOSμ as a regulator of G6PDH activity in skeletal muscle. G6PDH activity modulates insulin-independent glucose uptake in skeletal muscle.
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Affiliation(s)
- Robert S Lee-Young
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, VIC, Australia.
| | - Nolan J Hoffman
- Diabetes & Metabolism Division, Garvan Institute of Medical Research, NSW, Australia
| | - Kate T Murphy
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Melbourne, VIC, Australia
| | - Darren C Henstridge
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Dorit Samocha-Bonet
- Diabetes & Metabolism Division, Garvan Institute of Medical Research, NSW, Australia
| | - Andrew L Siebel
- Metabolic and Vascular Physiology Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Peter Iliades
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Borivoj Zivanovic
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Yet H Hong
- Institute for Sports, Exercise and Active Living, Victoria University, Footscray, VIC, Australia
| | - Timothy D Colgan
- Muscle Research and Therapeutics Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Michael J Kraakman
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Clinton R Bruce
- School of Exercise and Nutrition Sciences, Deakin University, Burwood, VIC, Australia
| | - Paul Gregorevic
- Muscle Research and Therapeutics Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Glenn K McConell
- Institute for Sports, Exercise and Active Living, Victoria University, Footscray, VIC, Australia
| | - Gordon S Lynch
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Melbourne, VIC, Australia
| | - Grant R Drummond
- Vascular Biology and Immunopharmacology Group, Department of Pharmacology, Monash University, Clayton, VIC, Australia
| | - Bronwyn A Kingwell
- Metabolic and Vascular Physiology Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Jerry R Greenfield
- Diabetes & Metabolism Division, Garvan Institute of Medical Research, NSW, Australia
| | - Mark A Febbraio
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, VIC, Australia; Diabetes & Metabolism Division, Garvan Institute of Medical Research, NSW, Australia.
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Abstract
Being born small for gestational age increases the risk of developing adult cardiovascular and metabolic diseases. This study aimed to examine if early‐life exercise could increase heart mass in the adult hearts from growth restricted rats. Bilateral uterine vessel ligation to induce uteroplacental insufficiency and fetal growth restriction in the offspring (Restricted) or sham surgery (Control) was performed on day 18 of gestation in WKY rats. A separate group of sham litters had litter size reduced to five pups at birth (Reduced litter), which restricted postnatal growth. Male offspring remained sedentary or underwent treadmill running from 5 to 9 weeks (early exercise) or 20 to 24 weeks of age (later exercise). Remarkably, in Control, Restricted, and Reduced litter groups, early exercise increased (P < 0.05) absolute and relative (to body mass) heart mass in adulthood. This was despite the animals being sedentary for ~4 months after exercise. Later exercise also increased adult absolute and relative heart mass (P < 0.05). Blood pressure was not significantly altered between groups or by early or later exercise. Phosphorylation of Akt Ser473 in adulthood was increased in the early exercise groups but not the later exercise groups. Microarray gene analysis and validation by real‐time PCR did not reveal any long‐term effects of early exercise on the expression of any individual genes. In summary, early exercise programs the heart for increased mass into adulthood, perhaps by an upregulation of protein synthesis based on greater phosphorylation of Akt Ser473.
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Affiliation(s)
- Glenn D Wadley
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
| | - Rhianna C Laker
- Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
| | - Glenn K McConell
- Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia Institute of Sport, Exercise and Active Living, Victoria University, Victoria, Victoria, Australia
| | - Mary E Wlodek
- Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
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Mason SA, Morrison D, McConell GK, Wadley GD. Muscle redox signalling pathways in exercise. Role of antioxidants. Free Radic Biol Med 2016; 98:29-45. [PMID: 26912034 DOI: 10.1016/j.freeradbiomed.2016.02.022] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 02/05/2016] [Accepted: 02/17/2016] [Indexed: 01/01/2023]
Abstract
Recent research highlights the importance of redox signalling pathway activation by contraction-induced reactive oxygen species (ROS) and nitric oxide (NO) in normal exercise-related cellular and molecular adaptations in skeletal muscle. In this review, we discuss some potentially important redox signalling pathways in skeletal muscle that are involved in acute and chronic responses to contraction and exercise. Specifically, we discuss redox signalling implicated in skeletal muscle contraction force, mitochondrial biogenesis and antioxidant enzyme induction, glucose uptake and muscle hypertrophy. Furthermore, we review evidence investigating the impact of major exogenous antioxidants on these acute and chronic responses to exercise. Redox signalling pathways involved in adaptive responses in skeletal muscle to exercise are not clearly elucidated at present, and further research is required to better define important signalling pathways involved. Evidence of beneficial or detrimental effects of specific antioxidant compounds on exercise adaptations in muscle is similarly limited, particularly in human subjects. Future research is required to not only investigate effects of specific antioxidant compounds on skeletal muscle exercise adaptations, but also to better establish mechanisms of action of specific antioxidants in vivo. Although we feel it remains somewhat premature to make clear recommendations in relation to application of specific antioxidant compounds in different exercise settings, a bulk of evidence suggests that N-acetylcysteine (NAC) is ergogenic through its effects on maintenance of muscle force production during sustained fatiguing events. Nevertheless, a current lack of evidence from studies using performance tests representative of athletic competition and a potential for adverse effects with high doses (>70mg/kg body mass) warrants caution in its use for performance enhancement. In addition, evidence implicates high dose vitamin C (1g/day) and E (≥260 IU/day) supplementation in impairments to some skeletal muscle cellular adaptations to chronic exercise training. Thus, determining the utility of antioxidant supplementation in athletes likely requires a consideration of training and competition periodization cycles of athletes in addition to type, dose and duration of antioxidant supplementation.
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Affiliation(s)
- Shaun A Mason
- Centre for Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Dale Morrison
- Centre for Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia
| | - Glenn K McConell
- Clinical Exercise Science Research Program, Institute for Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia
| | - Glenn D Wadley
- Centre for Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Victoria, Australia.
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24
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Levinger I, Brennan-Speranza TC, Stepto NK, Jerums G, Parker L, McConell GK, Anderson M, Garnham A, Hare DL, Ebeling PR, Seeman E. A Single Dose of Prednisolone as a Modulator of Undercarboxylated Osteocalcin and Insulin Sensitivity Post-Exercise in Healthy Young Men: A Study Protocol. JMIR Res Protoc 2016; 5:e78. [PMID: 27259402 PMCID: PMC4912677 DOI: 10.2196/resprot.5119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 01/24/2016] [Accepted: 01/25/2016] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Undercarboxylated osteocalcin (ucOC) increases insulin sensitivity in mice. In humans, data are supportive, but the studies are mostly cross-sectional. Exercise increases whole-body insulin sensitivity, in part via ucOC, while acute glucocorticoid treatment suppresses ucOC in humans and mice. OBJECTIVES A single dose of prednisolone reduces the rise in ucOC produced by exercise, which partly accounts for the failed increase in insulin sensitivity following exercise. METHODS Healthy young men (n=12) aged 18 to 40 years will be recruited. Initial assessments will include analysis of fasting blood, body composition, aerobic power (VO2peak), and peak heart rate. Participants will then be randomly allocated, double-blind, to a single dose of 20 mg of prednisolone or placebo. The two experimental trials will involve 30 minutes of interval exercise (90%-95% peak heart rate), followed by 3 hours of recovery and 2 hours of euglycaemic- hyperinsulinaemic clamp (insulin clamp). Seven muscle biopsies and blood samples will be obtained at rest, following exercise and post-insulin clamps. RESULTS The study is funded by the National Heart Foundation of Australia and Victoria University. Enrollment has already commenced and data collection will be completed in 2016. CONCLUSION If the hypothesis is confirmed, the study will provide novel insights into the potential role of ucOC in insulin sensitivity in human subjects and will elucidate pathways involved in exercise-induced insulin sensitivity.
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Affiliation(s)
- Itamar Levinger
- Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia.
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Hong YH, Yang C, Betik AC, Lee-Young RS, McConell GK. Skeletal muscle glucose uptake during treadmill exercise in neuronal nitric oxide synthase-μ knockout mice. Am J Physiol Endocrinol Metab 2016; 310:E838-45. [PMID: 27006199 DOI: 10.1152/ajpendo.00513.2015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/17/2016] [Indexed: 11/22/2022]
Abstract
Nitric oxide influences intramuscular signaling that affects skeletal muscle glucose uptake during exercise. The role of the main NO-producing enzyme isoform activated during skeletal muscle contraction, neuronal nitric oxide synthase-μ (nNOSμ), in modulating glucose uptake has not been investigated in a physiological exercise model. In this study, conscious and unrestrained chronically catheterized nNOSμ(+/+) and nNOSμ(-/-) mice either remained at rest or ran on a treadmill at 17 m/min for 30 min. Both groups of mice demonstrated similar exercise capacity during a maximal exercise test to exhaustion (17.7 ± 0.6 vs. 15.9 ± 0.9 min for nNOSμ(+/+) and nNOSμ(-/-), respectively, P > 0.05). Resting and exercise blood glucose levels were comparable between the genotypes. Very low levels of NOS activity were detected in skeletal muscle from nNOSμ(-/-) mice, and exercise increased NOS activity only in nNOSμ(+/+) mice (4.4 ± 0.3 to 5.2 ± 0.4 pmol·mg(-1)·min(-1), P < 0.05). Exercise significantly increased glucose uptake in gastrocnemius muscle (5- to 7-fold) and, surprisingly, more so in nNOSμ(-/-) than in nNOSμ(+/+) mice (P < 0.05). This is in parallel with a greater increase in AMPK phosphorylation during exercise in nNOSμ(-/-) mice. In conclusion, nNOSμ is not essential for skeletal muscle glucose uptake during exercise, and the higher skeletal muscle glucose uptake during exercise in nNOSμ(-/-) mice may be due to compensatory increases in AMPK activation.
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Affiliation(s)
- Yet Hoi Hong
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia; Clinical Exercise Science Program, Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria, Australia; Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia; and
| | - Christine Yang
- Cellular and Molecular Metabolism, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Andrew C Betik
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia; Clinical Exercise Science Program, Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria, Australia
| | - Robert S Lee-Young
- Cellular and Molecular Metabolism, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Glenn K McConell
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia; Clinical Exercise Science Program, Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria, Australia
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26
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Betik AC, Aguila J, McConell GK, McAinch AJ, Mathai ML. Tocotrienols and Whey Protein Isolates Substantially Increase Exercise Endurance Capacity in Diet -Induced Obese Male Sprague-Dawley Rats. PLoS One 2016; 11:e0152562. [PMID: 27058737 PMCID: PMC4825941 DOI: 10.1371/journal.pone.0152562] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 03/16/2016] [Indexed: 12/16/2022] Open
Abstract
Background and Aims Obesity and impairments in metabolic health are associated with reductions in exercise capacity. Both whey protein isolates (WPIs) and vitamin E tocotrienols (TCTs) exert favorable effects on obesity-related metabolic parameters. This research sought to determine whether these supplements improved exercise capacity and increased glucose tolerance in diet-induced obese rats. Methods Six week old male rats (n = 35) weighing 187 ± 32g were allocated to either: Control (n = 9), TCT (n = 9), WPI (n = 8) or TCT + WPI (n = 9) and placed on a high-fat diet (40% of energy from fat) for 10 weeks. Animals received 50mg/kg body weight and 8% of total energy intake per day of TCTs and/or WPIs respectively. Food intake, body composition, glucose tolerance, insulin sensitivity, exercise capacity, skeletal muscle glycogen content and oxidative enzyme activity were determined. Results Both TCT and WPI groups ran >50% longer (2271 ± 185m and 2195 ± 265m respectively) than the Control group (1428 ± 139m) during the run to exhaustion test (P<0.05), TCT + WPI did not further improve exercise endurance (2068 ± 104m). WPIs increased the maximum in vitro activity of beta-hydroxyacyl-CoA in the soleus muscle (P<0.05 vs. Control) but not in the plantaris. Citrate synthase activity was not different between groups. Neither supplement had any effect on weight gain, adiposity, glucose tolerance or insulin sensitivity. Conclusion Ten weeks of both TCTs and WPIs increased exercise endurance by 50% in sedentary, diet-induced obese rats. These positive effects of TCTs and WPIs were independent of body weight, adiposity or glucose tolerance.
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Affiliation(s)
- Andrew C. Betik
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia
- * E-mail:
| | - Jay Aguila
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
| | - Glenn K. McConell
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia
| | - Andrew J. McAinch
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia
| | - Michael L. Mathai
- Centre for Chronic Disease, College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
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Betteridge S, Bescós R, Martorell M, Pons A, Garnham AP, Stathis CC, McConell GK. No effect of acute beetroot juice ingestion on oxygen consumption, glucose kinetics, or skeletal muscle metabolism during submaximal exercise in males. J Appl Physiol (1985) 2016; 120:391-8. [DOI: 10.1152/japplphysiol.00658.2015] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/26/2015] [Indexed: 01/08/2023] Open
Abstract
Beetroot juice, which is rich in nitrate (NO3−), has been shown in some studies to decrease oxygen consumption (V̇o2) for a given exercise workload, i.e., increasing efficiency and exercise tolerance. Few studies have examined the effect of beetroot juice or nitrate supplementation on exercise metabolism. Eight healthy recreationally active males participated in three trials involving ingestion of either beetroot juice (Beet; ∼8 mmol NO3−), Placebo (nitrate-depleted Beet), or Beet + mouthwash (Beet+MW), all of which were performed in a randomized single-blind crossover design. Two-and-a-half hours later, participants cycled for 60 min on an ergometer at 65% of V̇o2 peak. [6,6-2H]glucose was infused to determine glucose kinetics, blood samples obtained throughout exercise, and skeletal muscle biopsies that were obtained pre- and postexercise. Plasma nitrite [NO2−] increased significantly (∼130%) with Beet, and this was attenuated in MW+Beet. Beet and Beet+MW had no significant effect on oxygen consumption, blood glucose, blood lactate, plasma nonesterified fatty acids, or plasma insulin during exercise. Beet and Beet+MW also had no significant effect on the increase in glucose disposal during exercise. In addition, Beet and Beet+MW had no significant effect on the decrease in muscle glycogen and phosphocreatine and the increase in muscle creatine, lactate, and phosphorylated acetyl CoA carboxylase during exercise. In conclusion, at the dose used, acute ingestion of beetroot juice had little effect on skeletal muscle metabolism during exercise.
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Affiliation(s)
- Scott Betteridge
- College of Health and Biomedicine, Victoria University, Melbourne, Australia
- Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Melbourne, Australia
| | - Raúl Bescós
- Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Melbourne, Australia
| | - Miquel Martorell
- Laboratory of Physical Activity Science, Research Group on Community Nutrition and Oxidative Stress, University of Balearic Islands, Palma Mallorca, Spain
- Nutrition and Dietetics Department, School of Pharmacy, University of Concepcion, Concepcion, Chile
| | - Antoni Pons
- Laboratory of Physical Activity Science, Research Group on Community Nutrition and Oxidative Stress, University of Balearic Islands, Palma Mallorca, Spain
| | - Andrew P. Garnham
- School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Australia; and
| | - Christos C. Stathis
- College of Health and Biomedicine, Victoria University, Melbourne, Australia
| | - Glenn K. McConell
- College of Health and Biomedicine, Victoria University, Melbourne, Australia
- Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Melbourne, Australia
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Levinger I, Seeman E, Jerums G, McConell GK, Rybchyn MS, Cassar S, Byrnes E, Selig S, Mason RS, Ebeling PR, Brennan-Speranza TC. Glucose-loading reduces bone remodeling in women and osteoblast function in vitro. Physiol Rep 2016; 4:4/3/e12700. [PMID: 26847728 PMCID: PMC4758933 DOI: 10.14814/phy2.12700] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 01/14/2016] [Indexed: 12/02/2022] Open
Abstract
Aging is associated with a reduction in osteoblast life span and the volume of bone formed by each basic multicellular unit. Each time bone is resorbed, less is deposited producing microstructural deterioration. Aging is also associated with insulin resistance and hyperglycemia, either of which may cause, or be the result of, a decline in undercarboxylated osteocalcin (ucOC), a protein produced by osteoblasts that increases insulin sensitivity. We examined whether glucose‐loading reduces bone remodeling and ucOC in vivo and osteoblast function in vitro, and so compromises bone formation. We administered an oral glucose tolerance test (OGTT) to 18 pre and postmenopausal, nondiabetic women at rest and following exercise and measured serum levels of bone remodeling markers (BRMs) and ucOC. We also assessed whether increasing glucose concentrations with or without insulin reduced survival and activity of cultured human osteoblasts. Glucose‐loading at rest and following exercise reduced BRMs in pre and postmenopausal women and reduced ucOC in postmenopausal women. Higher glucose correlated negatively, whereas insulin correlated positively, with baseline BRMs and ucOC. The increase in serum glucose following resting OGTT was associated with the reduction in bone formation markers. D‐glucose (>10 mmol L−1) increased osteoblast apoptosis, reduced cell activity and osteocalcin expression compared with 5 mmol L−1. Insulin had a protective effect on these parameters. Collagen expression in vitro was not affected in this time course. In conclusion, glucose exposure reduces BRMs in women and exercise failed to attenuate this suppression effect. The suppressive effect of glucose on BRMs may be due to impaired osteoblast work and longevity. Whether glucose influences material composition and microstructure remains to be determined.
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Affiliation(s)
- Itamar Levinger
- Clinical Exercise Science Program, Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
| | - Ego Seeman
- Department of Endocrinology, Austin Health, University of Melbourne, Melbourne, Australia
| | - George Jerums
- Department of Endocrinology, Austin Health, University of Melbourne, Melbourne, Australia
| | - Glenn K McConell
- Clinical Exercise Science Program, Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia College of Health and Biomedicine, Victoria University, Melbourne, Australia
| | - Mark S Rybchyn
- Department of Physiology, Bosch Institute for Medical Research, University of Sydney, Sydney, Australia
| | - Samantha Cassar
- Clinical Exercise Science Program, Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
| | | | - Steve Selig
- School of Exercise & Nutrition Sciences, Deakin University, Melbourne, Australia
| | - Rebecca S Mason
- Department of Physiology, Bosch Institute for Medical Research, University of Sydney, Sydney, Australia
| | - Peter R Ebeling
- Department of Medicine, School of Clinical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia
| | - Tara C Brennan-Speranza
- Department of Physiology, Bosch Institute for Medical Research, University of Sydney, Sydney, Australia
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Goodman CA, Pol D, Zacharewicz E, Lee-Young RS, Snow RJ, Russell AP, McConell GK. Statin-Induced Increases in Atrophy Gene Expression Occur Independently of Changes in PGC1α Protein and Mitochondrial Content. PLoS One 2015; 10:e0128398. [PMID: 26020641 PMCID: PMC4447258 DOI: 10.1371/journal.pone.0128398] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 04/27/2015] [Indexed: 11/18/2022] Open
Abstract
One serious side effect of statin drugs is skeletal muscle myopathy. Although the mechanism(s) responsible for statin myopathy remains to be fully determined, an increase in muscle atrophy gene expression and changes in mitochondrial content and/or function have been proposed to play a role. In this study, we examined the relationship between statin-induced expression of muscle atrophy genes, regulators of mitochondrial biogenesis, and markers of mitochondrial content in slow- (ST) and fast-twitch (FT) rat skeletal muscles. Male Sprague Dawley rats were treated with simvastatin (60 or 80 mg·kg-1·day-1) or vehicle control via oral gavage for 14 days. In the absence of overt muscle damage, simvastatin treatment induced an increase in atrogin-1, MuRF1 and myostatin mRNA expression; however, these were not associated with changes in peroxisome proliferator gamma co-activator 1 alpha (PGC-1α) protein or markers of mitochondrial content. Simvastatin did, however, increase neuronal nitric oxide synthase (nNOS), endothelial NOS (eNOS) and AMPK α-subunit protein expression, and tended to increase total NOS activity, in FT but not ST muscles. Furthermore, simvastatin induced a decrease in β-hydroxyacyl CoA dehydrogenase (β-HAD) activity only in FT muscles. These findings suggest that the statin-induced activation of muscle atrophy genes occurs independent of changes in PGC-1α protein and mitochondrial content. Moreover, muscle-specific increases in NOS expression and possibly NO production, and decreases in fatty acid oxidation, could contribute to the previously reported development of overt statin-induced muscle damage in FT muscles.
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Affiliation(s)
- Craig A. Goodman
- Department of Physiology, University of Melbourne, Parkville, Victoria, Australia
- Institute of Sport, Exercise and Active Living and the College of Health and Biomedicine, Victoria University, Victoria, Australia
- * E-mail:
| | - Derk Pol
- Department of Physiology, University of Melbourne, Parkville, Victoria, Australia
| | - Evelyn Zacharewicz
- Centre for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
| | - Robert S. Lee-Young
- Cellular and Molecular Metabolism Laboratory, Division of Metabolism and Obesity, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Rod J. Snow
- Centre for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
| | - Aaron P. Russell
- Centre for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
| | - Glenn K. McConell
- Department of Physiology, University of Melbourne, Parkville, Victoria, Australia
- Institute of Sport, Exercise and Active Living and the College of Health and Biomedicine, Victoria University, Victoria, Australia
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Hong YH, Betik AC, Premilovac D, Dwyer RM, Keske MA, Rattigan S, McConell GK. No effect of NOS inhibition on skeletal muscle glucose uptake during in situ hindlimb contraction in healthy and diabetic Sprague-Dawley rats. Am J Physiol Regul Integr Comp Physiol 2015; 308:R862-71. [DOI: 10.1152/ajpregu.00412.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 03/10/2015] [Indexed: 11/22/2022]
Abstract
Nitric oxide (NO) has been shown to be involved in skeletal muscle glucose uptake during contraction/exercise, especially in individuals with Type 2 diabetes (T2D). To examine the potential mechanisms, we examined the effect of local NO synthase (NOS) inhibition on muscle glucose uptake and muscle capillary blood flow during contraction in healthy and T2D rats. T2D was induced in Sprague-Dawley rats using a combined high-fat diet (23% fat wt/wt for 4 wk) and low-dose streptozotocin injections (35 mg/kg). Anesthetized animals had one hindlimb stimulated to contract in situ for 30 min (2 Hz, 0.1 ms, 35 V) with the contralateral hindlimb rested. After 10 min, the NOS inhibitor, NG-nitro-l-arginine methyl ester (l-NAME; 5 μM) or saline was continuously infused into the femoral artery of the contracting hindlimb until the end of contraction. Surprisingly, there was no increase in skeletal muscle NOS activity during contraction in either group. Local NOS inhibition had no effect on systemic blood pressure or muscle contraction force, but it did cause a significant attenuation of the increase in femoral artery blood flow in control and T2D rats. However, NOS inhibition did not attenuate the increase in muscle capillary recruitment during contraction in these rats. Muscle glucose uptake during contraction was significantly higher in T2D rats compared with controls but, unlike our previous findings in hooded Wistar rats, NOS inhibition had no effect on glucose uptake during contraction. In conclusion, NOS inhibition did not affect muscle glucose uptake during contraction in control or T2D Sprague-Dawley rats, and this may have been because there was no increase in NOS activity during contraction.
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Affiliation(s)
- Yet Hoi Hong
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria, Australia
- Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Andrew C. Betik
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria, Australia
| | - Dino Premilovac
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia; and
| | - Renee M. Dwyer
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia; and
- School of Medicine, University of Tasmania, Hobart, Tasmania, Australia
| | - Michelle A. Keske
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia; and
| | - Stephen Rattigan
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia; and
| | - Glenn K. McConell
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia
- Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Victoria, Australia
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Hanson ED, Sakkal S, Baindur-Hudson S, Violet J, Battaglini CL, McConell GK, Hayes A. Cytotoxic Lymphocyte Response to Moderate Intensity Aerobic Exercise in Prostate Cancer Survivors. Med Sci Sports Exerc 2015. [DOI: 10.1249/01.mss.0000478680.15510.e7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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McConell GK, Kaur G, Falcão-Tebas F, Hong YH, Gatford KL. Acute exercise increases insulin sensitivity in adult sheep: a new preclinical model. Am J Physiol Regul Integr Comp Physiol 2015; 308:R500-6. [DOI: 10.1152/ajpregu.00466.2014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In healthy humans and rodents, chronic and acute exercise improves subsequent insulin sensitivity of skeletal muscle. A large animal species with similar metabolic responses to exercise would permit longitudinal studies, including repeated biopsies of muscle and other tissues not possible in rodents, and enable study of interactions with insulin-resistant physiological states not feasible in humans. Therefore, we examined whether acute exercise increases insulin sensitivity in adult sheep. Insulin sensitivity was measured by hyperinsulinemic euglycemic clamp (HEC) in mature female sheep ( n = 7). Sheep were familiarized to treadmill walking and then performed an acute exercise bout (30 min, 8% slope, up to 4.4 km/h). A second HEC was conducted ∼18 h after the acute exercise. Musculus semimembranosus biopsies were obtained before and after each HEC. Glucose infusion rate during the HEC increased 40% ( P = 0.003) and insulin sensitivity (glucose infusion rate/plasma insulin concentration) increased 32% ( P = 0.028) after acute exercise. Activation of proximal insulin signaling in skeletal muscle after the HEC, measured as Ser473 phosphorylation of Akt, increased approximately five-fold in response to insulin ( P < 0.001) and was unaltered by acute exercise performed 18 h earlier. PGC1α and GLUT4 protein, glycogen content and citrate synthase activity in skeletal muscle did not change in response to insulin or exercise. In conclusion, improved insulin sensitivity and unchanged proximal insulin signaling on the day after acute exercise in sheep are consistent with responses in humans and rodents, suggesting that the sheep is an appropriate large-animal model in which to study responses to exercise.
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Affiliation(s)
- Glenn K. McConell
- Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Melbourne, Victoria, Australia
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia; and
| | - Gunveen Kaur
- Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Melbourne, Victoria, Australia
| | - Filippe Falcão-Tebas
- Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Melbourne, Victoria, Australia
| | - Yet H. Hong
- Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University, Melbourne, Victoria, Australia
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia; and
| | - Kathryn L. Gatford
- Robinson Research Institute and School of Paediatrics and Reproductive Health, University of Adelaide, Adelaide, South Australia, Australia
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Hong YH, Frugier T, Zhang X, Murphy RM, Lynch GS, Betik AC, Rattigan S, McConell GK. Glucose uptake during contraction in isolated skeletal muscles from neuronal nitric oxide synthase μ knockout mice. J Appl Physiol (1985) 2015; 118:1113-21. [PMID: 25749441 DOI: 10.1152/japplphysiol.00056.2015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 02/28/2015] [Indexed: 01/25/2023] Open
Abstract
Inhibition of nitric oxide synthase (NOS) significantly attenuates the increase in skeletal muscle glucose uptake during contraction/exercise, and a greater attenuation is observed in individuals with Type 2 diabetes compared with healthy individuals. Therefore, NO appears to play an important role in mediating muscle glucose uptake during contraction. In this study, we investigated the involvement of neuronal NOSμ (nNOSμ), the main NOS isoform activated during contraction, on skeletal muscle glucose uptake during ex vivo contraction. Extensor digitorum longus muscles were isolated from nNOSμ(-/-) and nNOSμ(+/+) mice. Muscles were contracted ex vivo in a temperature-controlled (30°C) organ bath with or without the presence of the NOS inhibitor N(G)-monomethyl-l-arginine (L-NMMA) and the NOS substrate L-arginine. Glucose uptake was determined by radioactive tracers. Skeletal muscle glucose uptake increased approximately fourfold during contraction in muscles from both nNOSμ(-/-) and nNOSμ(+/+) mice. L-NMMA significantly attenuated the increase in muscle glucose uptake during contraction in both genotypes. This attenuation was reversed by L-arginine, suggesting that L-NMMA attenuated the increase in muscle glucose uptake during contraction by inhibiting NOS and not via a nonspecific effect of the inhibitor. Low levels of NOS activity (~4%) were detected in muscles from nNOSμ(-/-) mice, and there was no evidence of compensation from other NOS isoform or AMP-activated protein kinase which is also involved in mediating muscle glucose uptake during contraction. These results indicate that NO regulates skeletal muscle glucose uptake during ex vivo contraction independently of nNOSμ.
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Affiliation(s)
- Yet Hoi Hong
- College of Health and Biomedicine and Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia; Department of Physiology, Faculty of Medicine, University of Malaya, Malaysia
| | - Tony Frugier
- Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, Australia
| | - Xinmei Zhang
- Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia
| | - Robyn M Murphy
- Department of Zoology, La Trobe University, Melbourne, Australia
| | - Gordon S Lynch
- Department of Physiology, University of Melbourne, Melbourne, Australia; and
| | - Andrew C Betik
- College of Health and Biomedicine and Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia
| | - Stephen Rattigan
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Australia
| | - Glenn K McConell
- College of Health and Biomedicine and Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia;
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Levinger I, Jerums G, Stepto NK, Parker L, Serpiello FR, McConell GK, Anderson M, Hare DL, Byrnes E, Ebeling PR, Seeman E. The effect of acute exercise on undercarboxylated osteocalcin and insulin sensitivity in obese men. J Bone Miner Res 2014; 29:2571-6. [PMID: 24861730 DOI: 10.1002/jbmr.2285] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/13/2014] [Accepted: 05/16/2014] [Indexed: 11/11/2022]
Abstract
Acute exercise improves insulin sensitivity for hours after the exercise is ceased. The skeleton contributes to glucose metabolism and insulin sensitivity via osteocalcin (OC) in its undercarboxylated (ucOC) form in mice. We tested the hypothesis that insulin sensitivity over the hours after exercise is associated with circulating levels of ucOC. Eleven middle-aged (58.1 ± 2.2 years mean ± SEM), obese (body mass index [BMI] = 33.1 ± 1.4 kg/m(2) ) nondiabetic men completed a euglycemic-hyperinsulinemic clamp at rest (rest-control) and at 60 minutes after exercise (4 × 4 minutes of cycling at 95% of HRpeak ). Insulin sensitivity was determined by glucose infusion rate relative to body mass (GIR, mL/kg/min) as well as GIR per unit of insulin (M-value). Blood samples and five muscle biopsies were obtained; two at the resting-control session, one before and one after clamping, and three in the exercise session, at rest, 60 minutes after exercise, and after the clamp. Exercise increased serum ucOC (6.4 ± 2.1%, p = 0.013) but not total OC (p > 0.05). Blood glucose was ∼6% lower and insulin sensitivity was ∼35% higher after exercise compared with control (both p < 0.05). Phosphorylated (P)-AKT (Ak thymoma) was higher after exercise and insulin compared with exercise alone (no insulin) and insulin alone (no exercise, all p < 0.05). In a multiple-linear regression including BMI, age, and aerobic fitness, ucOC was associated with whole-body insulin sensitivity at rest (β = 0.59, p = 0.023) and after exercise (β = 0.66, p = 0.005). Insulin sensitivity, after acute exercise, is associated with circulating levels of ucOC in obese men. Whether ucOC has a direct effect on skeletal muscle insulin sensitivity after exercise is yet to be determined.
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Affiliation(s)
- Itamar Levinger
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, Australia; Australian Institute of Musculoskeletal Science, NorthWest Academic Centre, The University of Melbourne, Western Health, Melbourne, Australia
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Abstract
Nitric oxide is produced within skeletal muscle fibres and has various functions in skeletal muscle. There is evidence that NO may be essential for normal increases in skeletal muscle glucose uptake during contraction/exercise. Although there have been some discrepant results, it has been consistently demonstrated that inhibition of NO synthase (NOS) attenuates the increase in skeletal muscle glucose uptake during contraction in mouse and rat muscle ex vivo, during in situ contraction in rats and during exercise in humans. The NO-mediated increase in skeletal muscle glucose uptake during contraction/exercise is probably due to the modulation of intramuscular signalling that ultimately increases glucose transporter 4 (GLUT4) translocation and is, surprisingly, independent of blood flow. In this review, we discuss the evidence for and against a role of NO in regulating skeletal muscle glucose uptake during contraction/exercise and outline the possible mechanism(s) involved. Emerging findings regarding the role of neuronal NOS mu (nNOSμ) in this process are also discussed.
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Affiliation(s)
- Yet Hoi Hong
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia Department of Physiology, Faculty of Medicine, University of Malaya, Malaysia
| | - Andrew C Betik
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia
| | - Glenn K McConell
- College of Health and Biomedicine, Victoria University, Melbourne, Victoria, Australia Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia
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Yau SW, Henry BA, Russo VC, McConell GK, Clarke IJ, Werther GA, Sabin MA. Leptin enhances insulin sensitivity by direct and sympathetic nervous system regulation of muscle IGFBP-2 expression: evidence from nonrodent models. Endocrinology 2014; 155:2133-43. [PMID: 24654786 DOI: 10.1210/en.2013-2099] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Leptin is produced from white adipose tissue and acts primarily to regulate energy balance. Obesity is associated with leptin resistance and increased circulating levels of leptin. Leptin has recently been shown to influence levels of IGF binding protein-2 (IGFBP-2), a protein that is reduced in obesity and type 2 diabetes. Overexpression of IGFBP-2 protects against obesity and type 2 diabetes. As such, IGFBP-2 signaling may represent a novel pathway by which leptin regulates insulin sensitivity. We sought to investigate how leptin regulates skeletal muscle IGFBP-2 levels and to assess the impact of this on insulin signaling and glucose uptake. In vitro experiments were undertaken in cultured human skeletal myotubes, whereas in vivo experiments assessed the effect of intracerebroventricular leptin on peripheral skeletal muscle IGFBP-2 expression and insulin sensitivity in sheep. Leptin directly increased IGFBP-2 mRNA and protein in human skeletal muscle through both signal transducer and activator of transcription-3 and phosphatidylinositol 3-kinase signaling, in parallel with enhanced insulin signaling. Silencing IGFBP-2 lowered leptin- and insulin-stimulated protein kinase B phosphorylation and glucose uptake. In in vivo experiments, intracerebroventricular leptin significantly increased hind-limb skeletal muscle IGFBP-2, an effect completely blocked by concurrent peripheral infusion of a β-adrenergic blocking agent. Sheep receiving central leptin showed improvements in glucose tolerance and circulating insulin levels after an iv glucose load. In summary, leptin regulates skeletal muscle IGFBP-2 by both direct peripheral and central (via the sympathetic nervous system) mechanisms, and these likely impact on peripheral insulin sensitivity and glucose metabolism.
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Affiliation(s)
- Steven W Yau
- Centre for Hormone Research (S.W.Y., V.C.R., G.A.W., M.A.S.), Murdoch Childrens Research Institute and Royal Children's Hospital, and Department of Paediatrics (S.W.Y., V.C.R., G.A.W., M.A.S.), University of Melbourne, Melbourne, Victoria 3052, Australia; Department of Physiology (S.W.Y., B.A.H., I.J.C., M.A.S.), Monash University, Melbourne, Victoria 3800, Australia; and Institute of Sport, Exercise and Active Living and the College of Health and Biomedicine (G.K.M.), Victoria University, Melbourne, Victoria 3011, Australia
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Gatford KL, Kaur G, Falcão-Tebas F, Wadley GD, Wlodek ME, Laker RC, Ebeling PR, McConell GK. Exercise as an intervention to improve metabolic outcomes after intrauterine growth restriction. Am J Physiol Endocrinol Metab 2014; 306:E999-1012. [PMID: 24619880 DOI: 10.1152/ajpendo.00456.2013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Individuals born after intrauterine growth restriction (IUGR) are at an increased risk of developing diabetes in their adult life. IUGR impairs β-cell function and reduces β-cell mass, thereby diminishing insulin secretion. IUGR also induces insulin resistance, with impaired insulin signaling in muscle in adult humans who were small for gestational age (SGA) and in rodent models of IUGR. There is epidemiological evidence in humans that exercise in adults can reduce the risk of metabolic disease following IUGR. However, it is not clear whether adult IUGR individuals benefit to the same extent from exercise as do normal-birth-weight individuals, as our rat studies suggest less of a benefit in those born IUGR. Importantly, however, there is some evidence from studies in rats that exercise in early life might be able to reverse or reprogram the long-term metabolic effects of IUGR. Studies are needed to address gaps in current knowledge, including determining the mechanisms involved in the reprogramming effects of early exercise in rats, whether exercise early in life or in adulthood has similar beneficial metabolic effects in larger animal models in which insulin resistance develops after IUGR. Human studies are also needed to determine whether exercise training improves insulin secretion and insulin sensitivity to the same extent in IUGR adults as in control populations. Such investigations will have implications for customizing the recommended level and timing of exercise to improve metabolic health after IUGR.
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Affiliation(s)
- Kathryn L Gatford
- Robinson Institute and School of Paediatrics and Reproductive Health, University of Adelaide, Adelaide, South Australia, Australia
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Shaw CS, Levinger I, McConell GK, Stepto NK, Murphy RM. Imaging GLUT4 in isolated human skeletal muscle fibres. Obes Res Clin Pract 2013. [DOI: 10.1016/j.orcp.2013.12.701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wadley GD, Nicolas MA, Hiam DS, McConell GK. Xanthine oxidase inhibition attenuates skeletal muscle signaling following acute exercise but does not impair mitochondrial adaptations to endurance training. Am J Physiol Endocrinol Metab 2013; 304:E853-62. [PMID: 23462817 DOI: 10.1152/ajpendo.00568.2012] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The aim of this research was to examine the impact of the xanthine oxidase (XO) inhibitor allopurinol on the skeletal muscle activation of cell signaling kinases' and adaptations to mitochondrial proteins and antioxidant enzymes following acute endurance exercise and endurance training. Male Sprague-Dawley rats performed either acute exercise (60 min of treadmill running, 27 m/min, 5% incline) or 6 wk of endurance training (5 days/wk) while receiving allopurinol or vehicle. Allopurinol treatment reduced XO activity to 5% of the basal levels (P < 0.05), with skeletal muscle uric acid levels being almost undetectable. Following acute exercise, skeletal muscle oxidized glutathione (GSSG) significantly increased in allopurinol- and vehicle-treated groups despite XO activity and uric acid levels being unaltered by acute exercise (P < 0.05). This suggests that the source of ROS was not from XO. Surprisingly, muscle GSSG levels were significantly increased following allopurinol treatment. Following acute exercise, allopurinol treatment prevented the increase in p38 MAPK and ERK phosphorylation and attenuated the increase in mitochondrial transcription factor A (mtTFA) mRNA (P < 0.05) but had no effect on the increase in peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), nuclear respiratory factor-2, GLUT4, or superoxide dismutase mRNA. Allopurinol also had no impact on the endurance training-induced increases in PGC-1α, mtTFA, and mitochondrial proteins including cytochrome c, citrate synthase, and β-hydroxyacyl-CoA dehydrogenase. In conclusion, although allopurinol inhibits cell signaling pathways in response to acute exercise, the inhibitory effects of allopurinol appear unrelated to exercise-induced ROS production by XO. Allopurinol also has little effect on increases in mitochondrial proteins following endurance training.
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Affiliation(s)
- G D Wadley
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia.
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Stepto NK, Benziane B, Wadley GD, Chibalin AV, Canny BJ, Eynon N, McConell GK. Short-term intensified cycle training alters acute and chronic responses of PGC1α and Cytochrome C oxidase IV to exercise in human skeletal muscle. PLoS One 2012; 7:e53080. [PMID: 23285255 PMCID: PMC3532354 DOI: 10.1371/journal.pone.0053080] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 11/28/2012] [Indexed: 01/18/2023] Open
Abstract
Reduced activation of exercise responsive signalling pathways have been reported in response to acute exercise after training; however little is known about the adaptive responses of the mitochondria. Accordingly, we investigated changes in mitochondrial gene expression and protein abundance in response to the same acute exercise before and after 10-d of intensive cycle training. Nine untrained, healthy participants (mean±SD; VO2peak 44.1±17.6 ml/kg/min) performed a 60 min bout of cycling exercise at 164±18 W (72% of pre-training VO2peak). Muscle biopsies were obtained from the vastus lateralis muscle at rest, immediately and 3 h after exercise. The participants then underwent 10-d of cycle training which included four high-intensity interval training sessions (6×5 min; 90–100% VO2peak) and six prolonged moderate-intensity sessions (45–90 min; 75% VO2peak). Participants repeated the pre-training exercise trial at the same absolute work load (64% of pre-training VO2peak). Muscle PGC1-α mRNA expression was attenuated as it increased by 11- and 4- fold (P<0.001) after exercise pre- and post-training, respectively. PGC1-α protein expression increased 1.5 fold (P<0.05) in response to exercise pre-training with no further increases after the post-training exercise bout. RIP140 protein abundance was responsive to acute exercise only (P<0.01). COXIV mRNA (1.6 fold; P<0.01) and COXIV protein expression (1.5 fold; P<0.05) were increased by training but COXIV protein expression was decreased (20%; P<0.01) by acute exercise pre- and post-training. These findings demonstrate that short-term intensified training promotes increased mitochondrial gene expression and protein abundance. Furthermore, acute indicators of exercise-induced mitochondrial adaptation appear to be blunted in response to exercise at the same absolute intensity following short-term training.
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Affiliation(s)
- Nigel K Stepto
- Institute of Sport Exercise and Active Living, Victoria University, Footscray, Victoria, Australia.
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Wadley GD, McConell GK, Goodman CA, Siebel AL, Westcott KT, Wlodek ME. Growth restriction in the rat alters expression of metabolic genes during postnatal cardiac development in a sex-specific manner. Physiol Genomics 2012; 45:99-105. [PMID: 23232075 DOI: 10.1152/physiolgenomics.00095.2012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study investigated the impact of uteroplacental insufficiency and growth restriction on the expression of genes related to mitochondrial biogenesis, glucose transport, and antioxidant defenses in cardiac tissue at embryonic day 20 (E20) and postnatal days 1, 7, and 35 in male and female Wistar rats (8-10 per group). Bilateral uterine vessel ligation to induce growth restriction (Restricted) or sham surgery was performed at pregnancy day 18. In male and female Controls, expression of most cardiac genes decreased during postnatal life, including genes involved in mitochondrial biogenesis regulation such as PGC-1α, NRF-2, and mtTFA and the glucose transporter GLUT-1 (P < 0.05). However, the pattern of gene expression during cardiac development differed in male and female Restricted rats compared with their respective Controls. These effects of restriction were observed at postnatal day 1, with female Restricted rats having delayed reductions in PGC-1α and GLUT-1, whereas males had exacerbated reductions in PGC-1α and mtTFA (P < 0.05). By day 35, cardiac gene expression in Restricted hearts was similar to Controls, except for expression of the antioxidant enzyme MnSOD, which was significantly lower in both sexes. In summary, during postnatal life male and female Control rats have similar patterns of expression for genes involved in mitochondrial biogenesis and glucose transport. However, following uteroplacental insufficiency these gene expression patterns diverge in males and females during early postnatal life, with MnSOD gene expression reduced in later postnatal life.
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Affiliation(s)
- Glenn D Wadley
- Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia.
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Abstract
The aim of the study was to determine the effect of a single bout of exercise on GLUT4 gene expression in muscle of patients with type 2 diabetes (T2D) and control subjects, matched for age and body mass index. Nine patients with T2D and nine control subjects performed 60 min of cycling exercise at ~55% peak power (W(max) ). Skeletal muscle biopsies were obtained at baseline, immediately post and 3-h post exercise. GLUT4 mRNA expression increased (p < 0.05) to a similar extent immediately post exercise in control (~60%) and T2D (~66%) subjects, and remained elevated (p < 0.05) 3-h post exercise with no differences between groups. Similarly, p-AMP-activated protein kinase, p38 mitogen-activated kinase and proliferator-activated receptor gamma co-activator-alpha mRNA expression were increased (p < 0.05) post exercise, and were not different between the groups. In conclusion, a single bout of exercise increased skeletal muscle GLUT4 mRNA expression in patients with T2D to a similar extent as in control subjects.
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Abstract
Nitric oxide (NO) is an important vasodilator and regulator in the cardiovascular system, and this link was the subject of a Nobel prize in 1998. However, NO also plays many other regulatory roles, including thrombosis, immune function, neural activity, and gastrointestinal function. Low concentrations of NO are thought to have important signaling effects. In contrast, high concentrations of NO can interact with reactive oxygen species, causing damage to cells and cellular components. A less-recognized site of NO production is within skeletal muscle, where small increases are thought to have beneficial effects such as regulating glucose uptake and possibly blood flow, but higher levels of production are thought to lead to deleterious effects such as an association with insulin resistance. This review will discuss the role of NO in skeletal muscle during and following exercise, including in mitochondrial biogenesis, muscle efficiency, and blood flow with a particular focus on its potential role in regulating skeletal muscle glucose uptake during exercise.
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Affiliation(s)
- Glenn K McConell
- Institute of Sport, Exercise and Active Living and the School of Biomedical and Health Sciences, Victoria University, Footscray, Victoria, Australia.
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Laker RC, Wlodek ME, Wadley GD, Gallo LA, Meikle PJ, McConell GK. Exercise early in life in rats born small does not normalize reductions in skeletal muscle PGC-1α in adulthood. Am J Physiol Endocrinol Metab 2012; 302:E1221-30. [PMID: 22354784 DOI: 10.1152/ajpendo.00583.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We have previously shown that 4 wk of exercise training early in life normalizes the otherwise greatly reduced pancreatic β-cell mass in adult male rats born small. The aim of the current study was to determine whether a similar normalization in adulthood of reduced skeletal muscle mitochondrial biogenesis markers and alterations in skeletal muscle lipids of growth-restricted male rats occurs following early exercise training. Bilateral uterine vessel ligation performed on day 18 of gestation resulted in Restricted offspring born small (P < 0.05) compared with both sham-operated Controls and a sham-operated Reduced litter group. Offspring remained sedentary or underwent treadmill running from 5-9 (early exercise) or 20-24 (later exercise) wk of age. At 24 wk of age, Restricted and Reduced litter offspring had lower (P < 0.05) skeletal muscle peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) protein expression compared with Control offspring. Early exercise training had the expected effect of increasing skeletal muscle markers of mitochondrial biogenesis, but, at this early age (9 wk), there was no deficit in Restricted and Reduced litter skeletal muscle mitochondrial biogenesis. Unlike our previous observations in pancreatic β-cell mass, there was no "reprogramming" effect of early exercise on adult skeletal muscle such that PGC-1α was lower in adult Restricted and Reduced litter offspring irrespective of exercise training. Later exercise training increased mitochondrial biogenesis in all groups. In conclusion, although the response to exercise training remains intact, early exercise training in rats born small does not have a reprogramming effect to prevent deficits in skeletal muscle markers of mitochondrial biogenesis in adulthood.
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Affiliation(s)
- Rhianna C Laker
- Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
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45
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Mollica JP, Dutka TL, Merry TL, Lamboley CR, McConell GK, McKenna MJ, Murphy RM, Lamb GD. S-glutathionylation of troponin I (fast) increases contractile apparatus Ca2+ sensitivity in fast-twitch muscle fibres of rats and humans. J Physiol 2012; 590:1443-63. [PMID: 22250211 DOI: 10.1113/jphysiol.2011.224535] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Oxidation can decrease or increase the Ca2+ sensitivity of the contractile apparatus in rodent fast-twitch (type II) skeletal muscle fibres, but the reactions and molecular targets involved are unknown. This study examined whether increased Ca2+ sensitivity is due to S-glutathionylation of particular cysteine residues. Skinned muscle fibres were directly activated in heavily buffered Ca2+ solutions to assess contractile apparatus Ca2+ sensitivity. Rat type II fibres were subjected to S-glutathionylation by successive treatments with 2,2′-dithiodipyridine (DTDP) and glutathione (GSH), and displayed a maximal increase in pCa50 (−log10 [Ca2+] at half-maximal force) of ∼0.24 pCa units, with little or no effect on maximum force or Hill coefficient. Partial similar effect was produced by exposure to oxidized gluthathione (GSSG, 10 mM) for 10 min at pH 7.1, and near-maximal effect by GSSG treatment at pH 8.5. None of these treatments significantly altered Ca2+ sensitivity in rat type I fibres. Western blotting showed that both the DTDP–GSH and GSSG–pH 8.5 treatments caused marked S-glutathionylation of the fast troponin I isoform (TnI(f)) present in type II fibres, but not of troponin C (TnC) or myosin light chain 2. Both the increased Ca2+ sensitivity and glutathionylation of TnI(f) were blocked by N-ethylmaleimide (NEM). S-nitrosoglutathione (GSNO) also increased Ca2+ sensitivity, but only in conditions where it caused S-glutathionylation of TnI(f). In human type II fibres from vastus lateralis muscle, DTDP–GSH treatment also caused similar increased Ca2+ sensitivity and S-glutathionylation of TnI(f). When the slow isoform of TnI in type I fibres of rat was partially substituted (∼30%) with TnI(f), DTDP–GSH treatment caused a significant increase in Ca2+ sensitivity (∼0.08 pCa units). TnIf in type II fibres from toad and chicken muscle lack Cys133 present in mammalian TnIf, and such fibres showed no change in Ca2+ sensitivity with DTDP–GSH nor any S-glutathionylation of TnI(f) (latter examined only in toad). Following 40 min of cycling exercise in human subjects (at ∼60% peak oxygen consumption), TnI(f) in vastus lateralis muscle displayed a marked increase in S-glutathionylation (∼4-fold). These findings show that S-glutathionylation of TnI(f), most probably at Cys133, increases the Ca2+ sensitivity of the contractile apparatus, and that this occurs in exercising humans, with likely beneficial effects on performance.
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Affiliation(s)
- J P Mollica
- Department of Zoology, La Trobe University, Melbourne, Victoria, 3086, Australia
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46
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Laker RC, Gallo LA, Wlodek ME, Siebel AL, Wadley GD, McConell GK. Short-term exercise training early in life restores deficits in pancreatic β-cell mass associated with growth restriction in adult male rats. Am J Physiol Endocrinol Metab 2011; 301:E931-40. [PMID: 21810930 DOI: 10.1152/ajpendo.00114.2011] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Fetal growth restriction is associated with reduced pancreatic β-cell mass, contributing to impaired glucose tolerance and diabetes. Exercise training increases β-cell mass in animals with diabetes and has long-lasting metabolic benefits in rodents and humans. We studied the effect of exercise training on islet and β-cell morphology and plasma insulin and glucose, following an intraperitoneal glucose tolerance test (IPGTT) in juvenile and adult male Wistar-Kyoto rats born small. Bilateral uterine vessel ligation performed on day 18 of pregnancy resulted in Restricted offspring born small compared with sham-operated Controls and also sham-operated Reduced litter offspring that had their litter size reduced to five pups at birth. Restricted, Control, and Reduced litter offspring remained sedentary or underwent treadmill running from 5 to 9 or 20 to 24 wk of age. Early life exercise increased relative islet surface area and β-cell mass across all groups at 9 wk, partially restoring the 60-68% deficit (P < 0.05) in Restricted offspring. Remarkably, despite no further exercise training after 9 wk, β-cell mass was restored in Restricted at 24 wk, while sedentary littermates retained a 45% deficit (P = 0.05) in relative β-cell mass. Later exercise training also restored Restricted β-cell mass to Control levels. In conclusion, early life exercise training in rats born small restored β-cell mass in adulthood and may have beneficial consequences for later metabolic health and disease.
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Affiliation(s)
- Rhianna C Laker
- Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
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47
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Church JE, Gehrig SM, Chee A, Naim T, Trieu J, McConell GK, Lynch GS. Early functional muscle regeneration after myotoxic injury in mice is unaffected by nNOS absence. Am J Physiol Regul Integr Comp Physiol 2011; 301:R1358-66. [PMID: 21849632 DOI: 10.1152/ajpregu.00096.2011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nitric oxide (NO) is an important signaling molecule produced in skeletal muscle primarily via the neuronal subtype of NO synthase (NOS1, or nNOS). While many studies have reported NO production to be important in muscle regeneration, none have examined the contribution of nNOS-derived NO to functional muscle regeneration (i.e., restoration of the muscle's ability to produce force) after acute myotoxic injury. In the present study, we tested the hypothesis that genetic deletion of nNOS would impair functional muscle regeneration after myotoxic injury in nNOS(-/-) mice. We found that nNOS(-/-) mice had lower body mass, lower muscle mass, and smaller myofiber cross-sectional area and that their tibialis anterior (TA) muscles produced lower absolute tetanic forces than those of wild-type littermate controls but that normalized or specific force was identical between the strains. In addition, muscles from nNOS(-/-) mice were more resistant to fatigue than those of wild-type littermates (P < 0.05). To determine whether deletion of nNOS affected muscle regeneration, TA muscles from nNOS(-/-) mice and wild-type littermates were injected with the myotoxin notexin to cause complete fiber degeneration, and muscle structure and function were assessed at 7 and 10 days postinjury. Myofiber cross-sectional area was lower in regenerating nNOS(-/-) mice than wild-type controls at 7 and 10 days postinjury; however, contrary to our original hypothesis, no difference in force-producing capacity of the TA muscle was evident between the two groups at either time point. Our findings reveal that nNOS is not essential for functional muscle regeneration after acute myotoxic damage.
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Affiliation(s)
- Jarrod E Church
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Melbourne, Victoria, Australia
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48
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Laker RC, Henry BA, Wadley GD, Clarke IJ, Canny BJ, McConell GK. Central infusion of leptin does not increase AMPK signaling in skeletal muscle of sheep. Am J Physiol Regul Integr Comp Physiol 2010; 300:R511-8. [PMID: 21148475 DOI: 10.1152/ajpregu.00079.2010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In sheep, central leptin infusion reduces food intake and increases energy expenditure in adipose tissue and skeletal muscle. The mechanisms for these peripheral effects of central leptin in sheep are not known but, on the basis of rodent studies, may involve AMPK. In mice, central leptin acutely increases both skeletal muscle AMPK activation and glucose uptake. Thus, to investigate whether these effects exist in higher-order mammals, ovariectomized Corriedale ewes (n = 4 per group) received a continuous lateral ventricular infusion (60 μl/h) of either leptin (50 μg/h) or artificial cerebrospinal fluid (aCSF; CON) for 8 days. Tritiated glucose (3-(3)H-glucose) was infused intravenously for calculation of whole body glucose turnover during both acute (6 h) and chronic (7-8 days) leptin/aCSF infusion. Muscle biopsies were also obtained. Leptin infusion reduced (P < 0.05) food intake and body weight, and it also increased plasma epinephrine concentration at 6 h and 7 days, suggesting increased sympathetic nerve activity. Despite this, and in contrast to rodent studies, central leptin infusion did not increase skeletal muscle AMPKα Thr(172) phosphorylation or ACCβ Ser(221) phosphorylation. Surprisingly, the glucose rate of appearance (glucose Ra) and rate of disappearance (glucose Rd) were reduced by both acute and chronic leptin infusion. Direct infusion of the AMPK activator 5-aminoimidazole-4-carboxyamide-ribonucleoside (AICAR) into the femoral artery increased skeletal muscle AMPK phosphorylation. In conclusion, although central leptin infusion in sheep caused the predicted reduction in food intake and increases plasma epinephrine concentration, it had no effect on AMPK activation in skeletal muscle and actually reduced glucose disposal. This suggests that there are species differences in the peripheral responses to central leptin infusion.
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Affiliation(s)
- Rhianna C Laker
- Department of Physiology, University of Melbourne, Victoria, Australia
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49
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Merry TL, Lynch GS, McConell GK. Downstream mechanisms of nitric oxide-mediated skeletal muscle glucose uptake during contraction. Am J Physiol Regul Integr Comp Physiol 2010; 299:R1656-65. [PMID: 20943856 DOI: 10.1152/ajpregu.00433.2010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
There is evidence that nitric oxide (NO) is required for the normal increases in skeletal muscle glucose uptake during contraction, but the mechanisms involved have not been elucidated. We examined whether NO regulates glucose uptake during skeletal muscle contractions via cGMP-dependent or cGMP-independent pathways. Isolated extensor digitorum longus (EDL) muscles from mice were stimulated to contract ex vivo, and potential NO signaling pathways were blocked by the addition of inhibitors to the incubation medium. Contraction increased (P < 0.05) NO synthase (NOS) activity (∼40%) and dichlorofluorescein (DCF) fluorescence (a marker of oxidant levels; ∼95%), which was prevented with a NOS inhibitor N(G)-monomethyl-L-arginine (L-NMMA), and antioxidants [nonspecific antioxidant, N-acetylcysteine (NAC); thiol-reducing agent, DTT], respectively. L-NMMA and NAC both attenuated glucose uptake during contraction by ∼50% (P < 0.05), and their effects were not additive. Neither the guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one, which prevents the formation of cGMP, the cGMP-dependent protein (PKG) inhibitor Rp-8-bromo-β-phenyl-1,N2-ethenoguanosine 3',5'-cyclic monophosphorothioate sodium salt nor white light, which breaks S-nitrosylated bonds, affects glucose uptake during contraction; however, DTT attenuated (P < 0.05) contraction-stimulated glucose uptake (by 70%). NOS inhibition and antioxidant treatment reduced contraction-stimulated increases in protein S-glutathionylation and tyrosine nitration (P < 0.05), without affecting AMPK or p38 MAPK phosphorylation. In conclusion, we provide evidence to suggest that NOS-derived oxidants regulate skeletal muscle glucose uptake during ex vivo contractions via a cGMP/PKG-, AMPK-, and p38 MAPK-independent pathway. In addition, it appears that NO and ROS may regulate skeletal muscle glucose uptake during contraction through a similar pathway.
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Affiliation(s)
- Troy L Merry
- Department of Physiology, University of Melbourne, Parkville, Victoria, Australia.
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50
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Laker RC, Wlodek ME, Wadley GD, McConell GK. Exercise training improves the metabolic phenotype of pre and postnatal growth restricted male rat offspring. FASEB J 2010. [DOI: 10.1096/fasebj.24.1_supplement.618.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Mary E Wlodek
- PhysiologyThe University of MelbourneParkvilleVICAustralia
| | - Glenn D Wadley
- PhysiologyThe University of MelbourneParkvilleVICAustralia
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