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Pignanelli C, Robertson AA, Hirsch SM, Power GA, Burr JF. The addition of blood flow restriction during resistance exercise does not increase prolonged low-frequency force depression. Exp Physiol 2024; 109:738-753. [PMID: 38562023 PMCID: PMC11061635 DOI: 10.1113/ep091753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 03/15/2024] [Indexed: 04/04/2024]
Abstract
At a given exercise intensity, blood flow restriction (BFR) reduces the volume of exercise required to impair post-exercise neuromuscular function. Compared to traditional exercise, the time course of recovery is less clear. After strenuous exercise, force output assessed with electrical muscle stimulation is impaired to a greater extent at low versus high stimulation frequencies, a condition known as prolonged low-frequency force depression (PLFFD). It is unclear if BFR increases PLFFD after exercise. This study tested if BFR during exercise increases PLFFD and slows recovery of neuromuscular function compared to regular exercise. Fifteen physically active participants performed six low-load sets of knee-extensions across four conditions: resistance exercise to task failure (RETF), resistance exercise to task failure with BFR applied continuously (BFRCONT) or intermittently (BFRINT), and resistance exercise matched to the lowest exercise volume condition (REVM). Maximal voluntary contraction (MVC) force output, voluntary activation and a force-frequency (1-100 Hz) curve were measured before and 0, 1, 2, 3, 4 and 24 h after exercise. Exercise to task failure caused similar reductions at 0 h for voluntary activation (RETF = 81.0 ± 14.2%, BFRINT = 80.9 ± 12.4% and BFRCONT = 78.6 ± 10.7%) and MVC force output (RETF = 482 ± 168 N, BFRINT = 432 ± 174 N, and BFRCONT = 443 ± 196 N), which recovered to baseline values between 4 and 24 h. PLFFD occurred only after RETF at 1 h supported by a higher frequency to evoke 50% of the force production at 100 Hz (1 h: 17.5 ± 4.4 vs. baseline: 15 ± 4.1 Hz, P = 0.0023), BFRINT (15.5 ± 4.0 Hz; P = 0.03), and REVM (14.9 ± 3.1 Hz; P = 0.002), with a trend versus BFRCONT (15.7 ± 3.5 Hz; P = 0.063). These findings indicate that, in physically active individuals, using BFR during exercise does not impair the recovery of neuromuscular function by 24 h post-exercise.
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Affiliation(s)
- Christopher Pignanelli
- Department of Human Health & Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
| | - Alexa A. Robertson
- Department of Human Health & Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
| | - Steven M. Hirsch
- Faculty of Kinesiology and Physical EducationUniversity of TorontoTorontoOntarioCanada
| | - Geoffrey A. Power
- Department of Human Health & Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
| | - Jamie F. Burr
- Department of Human Health & Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
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2
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Kano R, Tabuchi A, Tanaka Y, Shirakawa H, Hoshino D, Poole DC, Kano Y. In vivo cytosolic H 2O 2 changes and Ca 2+ homeostasis in mouse skeletal muscle. Am J Physiol Regul Integr Comp Physiol 2024; 326:R43-R52. [PMID: 37899753 DOI: 10.1152/ajpregu.00152.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 09/21/2023] [Accepted: 10/20/2023] [Indexed: 10/31/2023]
Abstract
Hydrogen peroxide (H2O2) and calcium ions (Ca2+) are functional regulators of skeletal muscle contraction and metabolism. Although H2O2 is one of the activators of the type-1 ryanodine receptor (RyR1) in the Ca2+ release channel, the interdependence between H2O2 and Ca2+ dynamics remains unclear. This study tested the following hypotheses using an in vivo model of mouse tibialis anterior (TA) skeletal muscle. 1) Under resting conditions, elevated cytosolic H2O2 concentration ([H2O2]cyto) leads to a concentration-dependent increase in cytosolic Ca2+ concentration ([Ca2+]cyto) through its effect on RyR1; and 2) in hypoxia (cardiac arrest) and muscle contractions (electrical stimulation), increased [H2O2]cyto induces Ca2+ accumulation. Cytosolic H2O2 (HyPer7) and Ca2+ (Fura-2) dynamics were resolved by TA bioimaging in young C57BL/6J male mice under four conditions: 1) elevated exogenous H2O2; 2) cardiac arrest; 3) twitch (1 Hz, 60 s) contractions; and 4) tetanic (30 s) contractions. Exogenous H2O2 (0.1-100 mM) induced a concentration-dependent increase in [H2O2]cyto (+55% at 0.1 mM; +280% at 100 mM) and an increase in [Ca2+]cyto (+3% at 1.0 mM; +8% at 10 mM). This increase in [Ca2+]cyto was inhibited by pharmacological inhibition of RyR1 by dantrolene. Cardiac arrest-induced hypoxia increased [H2O2]cyto (+33%) and [Ca2+]cyto (+20%) 50 min postcardiac arrest. Compared with the exogenous 1.0 mM H2O2 condition, [H2O2]cyto after tetanic muscle contractions rose less than one-tenth as much, whereas [Ca2+]cyto was 4.7-fold higher. In conclusion, substantial increases in [H2O2]cyto levels evoke only modest Ca2+ accumulation via their effect on the sarcoplasmic reticulum RyR1. On the other hand, contrary to hypoxia secondary to cardiac arrest, increases in [H2O2]cyto from muscle contractions are small, indicating that H2O2 generation is unlikely to be a primary factor driving the significant Ca2+ accumulation after, especially tetanic, muscle contractions.NEW & NOTEWORTHY We developed an in vivo mouse myocyte H2O2 imaging model during exogenous H2O2 loading, ischemic hypoxia induced by cardiac arrest, and muscle contractions. In this study, the interrelationship between cytosolic H2O2 levels and Ca2+ homeostasis during muscle contraction and hypoxic conditions was revealed. These results contribute to the elucidation of the mechanisms of muscle fatigue and exercise adaptation.
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Affiliation(s)
- Ryotaro Kano
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Chofu, Japan
- Research Fellowship for Young Scientists, Japan Society for the Promotion of Science, Tokyo, Japan
| | - Ayaka Tabuchi
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Chofu, Japan
| | - Yoshinori Tanaka
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Chofu, Japan
| | - Hideki Shirakawa
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Chofu, Japan
| | - Daisuke Hoshino
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Chofu, Japan
- Center for Neuroscience and Biomedical Engineering, University of Electro-Communications, Chofu, Japan
| | - David C Poole
- Departments of Anatomy and Physiology and Kinesiology, Kansas State University, Manhattan, Kansas, United States
| | - Yutaka Kano
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Chofu, Japan
- Center for Neuroscience and Biomedical Engineering, University of Electro-Communications, Chofu, Japan
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3
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Ciarlone GE, Swift JM, Williams BT, Mahon RT, Roney NG, Yu T, Gasier HG. 5-Hydroxymethylfurfural reduces skeletal muscle superoxide production and modifies force production in rats exposed to hypobaric hypoxia. Physiol Rep 2023; 11:e15743. [PMID: 37491570 PMCID: PMC10368650 DOI: 10.14814/phy2.15743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/17/2023] [Accepted: 05/25/2023] [Indexed: 07/27/2023] Open
Abstract
Decreased blood-tissue oxygenation at high altitude (HA) increases mitochondrial oxidant production and reduces exercise capacity. 5-Hydroxymethylfurfural (5-HMF) is an antioxidant that increases hemoglobin's binding affinity for oxygen. For these reasons, we hypothesized that 5-HMF would improve muscle performance in rats exposed to a simulated HA of ~5500 m. A secondary objective was to measure mitochondrial activity and dynamic regulation of fission and fusion because they are linked processes impacted by HA. Fisher 344 rats received 5-HMF (40 mg/kg/day) or vehicle during exposure to sea level or HA for 72 h. Right ankle plantarflexor muscle function was measured pre- and post-exposure. Post-exposure measurements included arterial blood gas and complete blood count, flexor digitorum brevis myofiber superoxide production and mitochondrial membrane potential (ΔΨm), and mitochondrial dynamic regulation in the soleus muscle. HA reduced blood oxygenation, increased superoxide levels and lowered ΔΨm, responses that were accompanied by decreased peak isometric torque and force production at frequencies >75 Hz. 5-HMF increased isometric force production and lowered oxidant production at sea level. In HA exposed animals, 5-HMF prevented a decline in isometric force production at 75-125 Hz, prevented an increase in superoxide levels, further decreased ΔΨm, and increased mitochondrial fusion 2 protein expression. These results suggest that 5-HMF may prevent a decrease in hypoxic force production during submaximal isometric contractions by an antioxidant mechanism.
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Affiliation(s)
- Geoffrey E Ciarlone
- Undersea Medicine Department, Naval Medical Research Center, Silver Spring, Maryland, USA
- Department of Military & Emergency Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Joshua M Swift
- Undersea Medicine Department, Naval Medical Research Center, Silver Spring, Maryland, USA
- Department of Military & Emergency Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Brian T Williams
- Undersea Medicine Department, Naval Medical Research Center, Silver Spring, Maryland, USA
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc, Bethesda, Maryland, USA
| | - Richard T Mahon
- Undersea Medicine Department, Naval Medical Research Center, Silver Spring, Maryland, USA
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc, Bethesda, Maryland, USA
| | - Nicholas G Roney
- Undersea Medicine Department, Naval Medical Research Center, Silver Spring, Maryland, USA
| | - Tianzheng Yu
- Department of Military & Emergency Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc, Bethesda, Maryland, USA
| | - Heath G Gasier
- Department of Military & Emergency Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
- The Duke Center for Hyperbaric Medicine & Environmental Physiology, Duke University, Durham, North Carolina, USA
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4
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Wang H, Shen Z, Huang R, Zhao A, Jiang J, Li P, Zhou X, Yang S, Hou L. A polymorphism in porcine miR-22 is associated with pork color. Front Vet Sci 2022; 9:939440. [PMID: 35968001 PMCID: PMC9366310 DOI: 10.3389/fvets.2022.939440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 06/28/2022] [Indexed: 11/20/2022] Open
Abstract
MicroRNAs (miRNAs) are posttranscriptional regulators that play key roles in meat color regulation. Changes in miRNA expression affect their target mRNAs, leading to multifunctional effects on biological processes and phenotypes. In this study, a G > A mutation site located upstream of the precursor miR-22 sequence in Suhuai pigs was significantly correlated with the meat color parameter a*(redness) of the porcine longissimus dorsi (LD) muscle. AA genotype individuals had the highest average meat color a* value and the lowest miR-22 level. When G > A mutation was performed in the miR-22 overexpression vector, miR-22 expression significantly decreased. Considering that Ca2+ homeostasis is closely related to pig meat color, our results further demonstrated that ELOVL6 is a direct target of miR-22 in pigs. The effects of miR-22 on skeletal muscle intracellular Ca2+ were partially caused by the suppression of ELOVL6 expression.
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Affiliation(s)
- Han Wang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Department of Animal Breeding, College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Zhonghao Shen
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Department of Animal Breeding, College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Ruihua Huang
- Institute of Swine Science, Department of Animal Breeding, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Ayong Zhao
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Department of Animal Breeding, College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Jiani Jiang
- Department of Statistical Sciences, University of Toronto, Toronto, ON, Canada
| | - Pinghua Li
- Institute of Swine Science, Department of Animal Breeding, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Xiaolong Zhou
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Department of Animal Breeding, College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Songbai Yang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, Department of Animal Breeding, College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, China
| | - Liming Hou
- Institute of Swine Science, Department of Animal Breeding, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
- *Correspondence: Liming Hou
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5
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Nogueira L, Gilmore NK, Hogan MC. Role of parvalbumin in fatigue-induced changes in force and cytosolic calcium transients in intact single mouse myofibers. J Appl Physiol (1985) 2022; 132:1041-1053. [PMID: 35238653 PMCID: PMC8993520 DOI: 10.1152/japplphysiol.00861.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
One of the most important cytosolic Ca2+ buffers present in mouse fast-twitch myofibers, but not in human myofibers, is parvalbumin (PV). Previous work using conventional PV knockout mice suggests that lifelong PV ablation increases fatigue resistance, possibly due to compensations in mitochondrial volume. In this work, PV gene ablation was induced only in adult mice (PV-KO), and contractile and cytosolic Ca2+ responses during fatigue were studied in isolated muscle and intact single myofibers. Results were compared to control littermates (PV-Ctr). We hypothesized that the reduced myofiber cytosolic Ca2+ buffering developed only in adult PV-KO mice leads to a larger cytosolic free Ca2+ concentration ([Ca2+]c) during repetitive contractions, increasing myofiber fatigue resistance. Extensor digitorum longus (EDL) muscles from PV-KO mice had higher force in unfused stimulations (~50%, P<0.05) and slowed relaxation (~46% higher relaxation time, P<0.05) vs PV-Ctr, but muscle fatigue resistance or fatigue-induced changes in relaxation were not different between genotypes (P>0.05). In intact single myofibers from flexor digitorum brevis (FDB) muscles, basal and tetanic [Ca2+]c during fatiguing contractions were higher in PV-KO (P<0.05), accompanied by a greater slowing in estimated sarcoplasmic reticulum (SR) Ca2+ pumping vs PV-Ctr myofibers (~84% reduction, P<0.05), but myofiber fatigue resistance was not different between genotypes (P>0.05). Our results demonstrate that although the estimated SR Ca2+ uptake was accelerated in PV-KO, the total energy demand by the major energy consumers in myofibers, the cross-bridges and SR Ca2+ ATPase, were not altered enough to affect the energy supply for contractions, and therefore fatigue resistance remained unaffected.
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Affiliation(s)
- Leonardo Nogueira
- Section of Physiology; Division of Pulmonary, Critical Care and Sleep Medicine; Department of Medicine, University of California San Diego, La Jolla, California, United States
| | - Natalie K Gilmore
- Section of Physiology; Division of Pulmonary, Critical Care and Sleep Medicine; Department of Medicine, University of California San Diego, La Jolla, California, United States
| | - Michael C Hogan
- Section of Physiology; Division of Pulmonary, Critical Care and Sleep Medicine; Department of Medicine, University of California San Diego, La Jolla, California, United States
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6
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Watanabe D, Kanzaki K, Wada M. [How to evaluate skeletal muscle function: suggestion from studies on skeletal muscle fatigue]. Nihon Yakurigaku Zasshi 2022; 157:9-14. [PMID: 34980819 DOI: 10.1254/fpj.21065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
In studies on skeletal muscle, an in vitro force measurement has been widely used to evaluate its function. However, it is recently suggested that in some cases, the results obtained by such measurement do not necessarily reflect the force in vivo, because the measurement has some disadvantages. For example, the muscles are contracted under different conditions from in vivo and there is no blood flow. To resolve this issue, we have developed an experimental system, in which muscles are contracted in vivo and the organelle function is subsequently estimated by an in vitro force measurement using a mechanically skinned fiber technique. This experimental system makes it possible to examine not only the muscle force in vivo but also the mechanisms of changes in the force at organelle levels. In this review, we depict the advantages and disadvantages of the in vitro and in vivo measurements of force and then discuss the effectiveness of our experimental system.
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Affiliation(s)
- Daiki Watanabe
- Graduate School of Humanities and Social Sciences, Hiroshima University
| | - Keita Kanzaki
- Faculty of Health Science & Technology, Kawasaki University of Medical Welfare
| | - Masanobu Wada
- Graduate School of Humanities and Social Sciences, Hiroshima University
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7
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Oxygen flux from capillary to mitochondria: integration of contemporary discoveries. Eur J Appl Physiol 2022; 122:7-28. [PMID: 34940908 PMCID: PMC8890444 DOI: 10.1007/s00421-021-04854-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 11/18/2021] [Indexed: 01/03/2023]
Abstract
Resting humans transport ~ 100 quintillion (1018) oxygen (O2) molecules every second to tissues for consumption. The final, short distance (< 50 µm) from capillary to the most distant mitochondria, in skeletal muscle where exercising O2 demands may increase 100-fold, challenges our understanding of O2 transport. To power cellular energetics O2 reaches its muscle mitochondrial target by dissociating from hemoglobin, crossing the red cell membrane, plasma, endothelial surface layer, endothelial cell, interstitial space, myocyte sarcolemma and a variable expanse of cytoplasm before traversing the mitochondrial outer/inner membranes and reacting with reduced cytochrome c and protons. This past century our understanding of O2's passage across the body's final O2 frontier has been completely revised. This review considers the latest structural and functional data, challenging the following entrenched notions: (1) That O2 moves freely across blood cell membranes. (2) The Krogh-Erlang model whereby O2 pressure decreases systematically from capillary to mitochondria. (3) Whether intramyocyte diffusion distances matter. (4) That mitochondria are separate organelles rather than coordinated and highly plastic syncytia. (5) The roles of free versus myoglobin-facilitated O2 diffusion. (6) That myocytes develop anoxic loci. These questions, and the intriguing notions that (1) cellular membranes, including interconnected mitochondrial membranes, act as low resistance conduits for O2, lipids and H+-electrochemical transport and (2) that myoglobin oxy/deoxygenation state controls mitochondrial oxidative function via nitric oxide, challenge established tenets of muscle metabolic control. These elements redefine muscle O2 transport models essential for the development of effective therapeutic countermeasures to pathological decrements in O2 supply and physical performance.
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8
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Cheng AJ, Ström J, Hwee DT, Malik FI, Westerblad H. Fast skeletal muscle troponin activator CK-2066260 mitigates skeletal muscle weakness independently of the underlying cause. J Cachexia Sarcopenia Muscle 2020; 11:1747-1757. [PMID: 32954682 PMCID: PMC7749611 DOI: 10.1002/jcsm.12624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 08/08/2020] [Accepted: 08/23/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Muscle weakness is a common symptom in numerous diseases and a regularly occurring problem associated with ageing. Prolonged low-frequency force depression (PLFFD) is a form of exercise-induced skeletal muscle weakness observed after exercise. Three different intramuscular mechanisms underlying PLFFD have been identified: decreased sarcoplasmic reticulum Ca2+ release, decreased myofibrillar Ca2+ sensitivity, and myofibrillar dysfunction. We here used these three forms of PLFFD as models to study the effectiveness of a fast skeletal muscle troponin activator, CK-2066260, to mitigate muscle weakness. METHODS Experiments were performed on intact single muscle fibres or fibre bundles from mouse flexor digitorum brevis, which were stimulated with electrical current pulses, while force and the free cytosolic [Ca2+ ] ([Ca2+ ]i ) were measured. PLFFD was induced by three different stimulation protocols: (i) repeated isometric contractions at low intensity (350 ms tetani given every 5 s for 100 contractions); (ii) repeated isometric contractions at high intensity (250 ms tetani given every 0.5 s for 300 contractions); and (iii) repeated eccentric contractions (350 ms tetani with 20% length increase given every 20 s for 10 contractions). The extent and cause of PLFFD were assessed by comparing the force-[Ca2+ ]i relationship at low (30 Hz) and high (120 Hz) stimulation frequencies before (control) and 30 min after induction of PLFFD, and after an additional 5 min of rest in the presence of CK-2066260 (10 μM). RESULTS Prolonged low-frequency force depression following low-intensity and high-intensity fatiguing contractions was predominantly due to decreased sarcoplasmic reticulum Ca2+ release and decreased myofibrillar Ca2+ sensitivity, respectively. CK-2066260 exposure resulted in marked increases in 30 Hz force from 52 ± 16% to 151 ± 13% and from 6 ± 4% to 98 ± 40% of controls with low-intensity and high-intensity contractions, respectively. Following repeated eccentric contractions, PLFFD was mainly due to myofibrillar dysfunction, and it was not fully reversed by CK-2066260 with 30 Hz force increasing from 48 ± 8% to 76 ± 6% of the control. CONCLUSIONS The fast skeletal muscle troponin activator CK-2066260 effectively mitigates muscle weakness, especially when it is caused by impaired activation of the myofibrillar contractile machinery due to either decreased sarcoplasmic reticulum Ca2+ release or reduced myofibrillar Ca2+ sensitivity.
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Affiliation(s)
- Arthur J Cheng
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.,School of Kinesiology and Health Science, Faculty of Health, York University, Toronto, Canada
| | - Jennifer Ström
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Darren T Hwee
- Research and Early Development, Cytokinetics, Inc., South San Francisco, CA, USA
| | - Fady I Malik
- Research and Early Development, Cytokinetics, Inc., South San Francisco, CA, USA
| | - Håkan Westerblad
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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9
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Aibara C, Okada N, Watanabe D, Shi J, Wada M. Effects of high-intensity interval exercise on muscle fatigue and SR function in rats: a comparison with moderate-intensity continuous exercise. J Appl Physiol (1985) 2020; 129:343-352. [DOI: 10.1152/japplphysiol.00223.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Over the past decade, high-intensity interval exercise (HIIE) training has received attention as a more efficient training to improve endurance capacity. It is unclear, however, whether the extent of acute exercise-related muscle fatigue differs between HIIE and moderate-intensity continuous exercise, traditional endurance training. Here we provide evidence that restoration of force production takes a longer time after HIIE, which is ascribable to long-lasting depressions in Ca2+ release of the sarcoplasmic reticulum.
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Affiliation(s)
- Chihiro Aibara
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Hiroshima, Japan
| | - Naoki Okada
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Hiroshima, Japan
| | - Daiki Watanabe
- Graduate School of Humanities and Social Sciences, Hiroshima University, Hiroshima, Japan
| | - Jiayu Shi
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Hiroshima, Japan
| | - Masanobu Wada
- Graduate School of Humanities and Social Sciences, Hiroshima University, Hiroshima, Japan
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10
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Cheng AJ, Chaillou T, Kamandulis S, Subocius A, Westerblad H, Brazaitis M, Venckunas T. Carbohydrates do not accelerate force recovery after glycogen-depleting followed by high-intensity exercise in humans. Scand J Med Sci Sports 2020; 30:998-1007. [PMID: 32187403 DOI: 10.1111/sms.13655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Prolonged low-frequency force depression (PLFFD) induced by fatiguing exercise is characterized by a persistent depression in submaximal contractile force during the recovery period. Muscle glycogen depletion is known to limit physical performance during prolonged low- and moderate-intensity exercise, and accelerating glycogen resynthesis with post-exercise carbohydrate intake can facilitate recovery and improve repeated bout exercise performance. Short-term, high-intensity exercise, however, can cause PLFFD without any marked decrease in glycogen. Here, we studied whether recovery from PLFFD was accelerated by carbohydrate ingestion after 60 minutes of moderate-intensity glycogen-depleting cycling exercise followed by six 30-seconds all-out cycling sprints. We used a randomized crossover study design where nine recreationally active males drank a beverage containing either carbohydrate or placebo after exercise. Blood glucose and muscle glycogen concentrations were determined at baseline, immediately post-exercise, and during the 3-hours recovery period. Transcutaneous electrical stimulation of the quadriceps muscle was performed to determine the extent of PLFFD by eliciting low-frequency (20 Hz) and high-frequency (100 Hz) stimulations. Muscle glycogen was severely depleted after exercise, with a significantly higher rate of muscle glycogen resynthesis during the 3-hours recovery period in the carbohydrate than in the placebo trials (13.7 and 5.4 mmol glucosyl units/kg wet weight/h, respectively). Torque at 20 Hz was significantly more depressed than 100 Hz torque during the recovery period in both conditions, and the extent of PLFFD (20/100 Hz ratio) was not different between the two trials. In conclusion, carbohydrate supplementation enhances glycogen resynthesis after glycogen-depleting exercise but does not improve force recovery when the exercise also involves all-out cycling sprints.
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Affiliation(s)
- Arthur J Cheng
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.,Faculty of Health, School of Kinesiology and Health Science, York University, Toronto, ON, Canada
| | - Thomas Chaillou
- School of Health Sciences, Örebro University, Örebro, Sweden
| | - Sigitas Kamandulis
- Sports Science and Innovation Institute, Lithuanian Sports University, Kaunas, Lithuania
| | - Andrejus Subocius
- Sports Science and Innovation Institute, Lithuanian Sports University, Kaunas, Lithuania.,Department of Surgery, Kaunas Clinical Hospital, Kaunas, Lithuania.,Clinic of Surgery, Republican Hospital of Kaunas, Kaunas, Lithuania
| | - Håkan Westerblad
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.,Sports Science and Innovation Institute, Lithuanian Sports University, Kaunas, Lithuania
| | - Marius Brazaitis
- Sports Science and Innovation Institute, Lithuanian Sports University, Kaunas, Lithuania
| | - Tomas Venckunas
- Sports Science and Innovation Institute, Lithuanian Sports University, Kaunas, Lithuania
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11
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Cheng AJ, Jude B, Lanner JT. Intramuscular mechanisms of overtraining. Redox Biol 2020; 35:101480. [PMID: 32179050 PMCID: PMC7284919 DOI: 10.1016/j.redox.2020.101480] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/08/2020] [Accepted: 02/24/2020] [Indexed: 01/04/2023] Open
Abstract
Strenuous exercise is a potent stimulus to induce beneficial skeletal muscle adaptations, ranging from increased endurance due to mitochondrial biogenesis and angiogenesis, to increased strength from hypertrophy. While exercise is necessary to trigger and stimulate muscle adaptations, the post-exercise recovery period is equally critical in providing sufficient time for metabolic and structural adaptations to occur within skeletal muscle. These cyclical periods between exhausting exercise and recovery form the basis of any effective exercise training prescription to improve muscle endurance and strength. However, imbalance between the fatigue induced from intense training/competitions, and inadequate post-exercise/competition recovery periods can lead to a decline in physical performance. In fact, prolonged periods of this imbalance may eventually lead to extended periods of performance impairment, referred to as the state of overreaching that may progress into overtraining syndrome (OTS). OTS may have devastating implications on an athlete's career and the purpose of this review is to discuss potential underlying mechanisms that may contribute to exercise-induced OTS in skeletal muscle. First, we discuss the conditions that lead to OTS, and their potential contributions to impaired skeletal muscle function. Then we assess the evidence to support or refute the major proposed mechanisms underlying skeletal muscle weakness in OTS: 1) glycogen depletion hypothesis, 2) muscle damage hypothesis, 3) inflammation hypothesis, and 4) the oxidative stress hypothesis. Current data implicates reactive oxygen and nitrogen species (ROS) and inflammatory pathways as the most likely mechanisms contributing to OTS in skeletal muscle. Finally, we allude to potential interventions that can mitigate OTS in skeletal muscle.
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Affiliation(s)
- Arthur J Cheng
- York University, Faculty of Health/ School of Kinesiology and Health Sciences, Muscle Health Research Centre/ Muscle Calcium Dynamics Lab, 351 Farquharson Life Sciences Building, Toronto, M3J 1P3, Canada
| | - Baptiste Jude
- Karolinska Institutet, Department of Physiology and Pharmacology, Molecular Muscle Physiology and Pathophysiology laboratory, Biomedicum C5, 17177, Stockholm, Sweden
| | - Johanna T Lanner
- Karolinska Institutet, Department of Physiology and Pharmacology, Molecular Muscle Physiology and Pathophysiology laboratory, Biomedicum C5, 17177, Stockholm, Sweden.
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12
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Bailey SJ, Gandra PG, Jones AM, Hogan MC, Nogueira L. Incubation with sodium nitrite attenuates fatigue development in intact single mouse fibres at physiological P O 2 . J Physiol 2019; 597:5429-5443. [PMID: 31541562 DOI: 10.1113/jp278494] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 09/20/2019] [Indexed: 12/22/2022] Open
Abstract
KEY POINTS Dietary nitrate supplementation increases plasma nitrite concentration, which provides an oxygen-independent source of nitric oxide and can delay skeletal muscle fatigue. Nitrate supplementation has been shown to increase myofibre calcium release and force production in mouse skeletal muscle during contractions at a supra-physiological oxygen tension, but it is unclear whether nitrite exposure can delay fatigue development and improve myofibre calcium handling at a near-physiological oxygen tension. Single mouse muscle fibres acutely treated with nitrite had a lower force and cytosolic calcium concentration during single non-fatiguing contractions at a near-physiological oxygen tension. Nitrite treatment delayed fatigue development during repeated fatiguing isometric contractions at near-physiological, but not at supra-physiological, oxygen tension in combination with better maintenance of myofilament calcium sensitivity and sarcoplasmic reticulum calcium pumping. These findings improve understanding of the mechanisms by which increased skeletal muscle nitrite exposure might be ergogenic and imply that this is related to improved calcium handling. ABSTRACT Dietary nitrate (NO3 - ) supplementation, which increases plasma nitrite (NO2 - ) concentration, has been reported to attenuate skeletal muscle fatigue development. Sarcoplasmic reticulum (SR) calcium (Ca2+ ) release is enhanced in isolated single skeletal muscle fibres following NO3 - supplementation or NO2 - incubation at a supra-physiological P O 2 but it is unclear whether NO2 - incubation can alter Ca2+ handling and fatigue development at a near-physiological P O 2 . We hypothesised that NO2 - treatment would improve Ca2+ handling and delay fatigue at a physiological P O 2 in intact single mouse skeletal muscle fibres. Each muscle fibre was perfused with Tyrode solution pre-equilibrated with either 20% ( P O 2 ∼150 Torr) or 2% O2 ( P O 2 = 15.6 Torr) in the absence and presence of 100 µM NaNO2 . At supra-physiological P O 2 (i.e. 20% O2 ), time to fatigue was lowered by 34% with NaNO2 (control: 257 ± 94 vs. NaNO2 : 159 ± 46 s, Cohen's d = 1.63, P < 0.05), but extended by 21% with NaNO2 at 2% O2 (control: 308 ± 217 vs. NaNO2 : 368 ± 242 s, d = 1.14, P < 0.01). During the fatiguing contraction protocol completed with NaNO2 at 2% O2 , peak cytosolic Ca2+ concentration ([Ca2+ ]c ) was not different (P > 0.05) but [Ca2+ ]c accumulation between contractions was lower, concomitant with a greater SR Ca2+ pumping rate (P < 0.05) compared to the control condition. These results demonstrate that increased exposure to NO2 - blunts fatigue development at near-physiological, but not at supra-physiological, P O 2 through enhancing SR Ca2+ pumping rate in single skeletal muscle fibres. These findings extend our understanding of the mechanisms by which increased NO2 - exposure can mitigate skeletal muscle fatigue development.
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Affiliation(s)
- Stephen J Bailey
- Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK.,School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Paulo G Gandra
- Section of Physiology; Division of Pulmonary, Critical Care & Sleep Medicine, Department of Medicine, University of California, San Diego, CA, USA.,Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (Unicamp), Campinas, Brazil
| | - Andrew M Jones
- Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Michael C Hogan
- Section of Physiology; Division of Pulmonary, Critical Care & Sleep Medicine, Department of Medicine, University of California, San Diego, CA, USA
| | - Leonardo Nogueira
- Section of Physiology; Division of Pulmonary, Critical Care & Sleep Medicine, Department of Medicine, University of California, San Diego, CA, USA.,Instituto de Bioquímica Médica Leopoldo de Meis (Medical Biochemistry Institute Leopoldo de Meis), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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13
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Chaillou T, Cheng AJ. Mechanisms of prolonged low-frequency force depression: in vivo studies get us closer to the truth. Am J Physiol Regul Integr Comp Physiol 2019; 316:R502-R503. [DOI: 10.1152/ajpregu.00063.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Thomas Chaillou
- School of Health Sciences, Örebro University, Örebro, Sweden
| | - Arthur J. Cheng
- School of Kinesiology and Health Science, Faculty of Health, York University, Toronto, Ontario, Canada
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14
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Watanabe D, Aibara C, Wada M. Treatment with EUK-134 improves sarcoplasmic reticulum Ca2+ release but not myofibrillar Ca2+ sensitivity after fatiguing contraction of rat fast-twitch muscle. Am J Physiol Regul Integr Comp Physiol 2019; 316:R543-R551. [DOI: 10.1152/ajpregu.00387.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Skeletal muscles undergoing vigorous activity can enter a state of prolonged low-frequency force depression (PLFFD). This study was conducted to examine whether antioxidant treatment is capable of accelerating the recovery from PLFFD, with a focus on the function of the sarcoplasmic reticulum (SR) and myofibril. One hour before fatiguing stimulation (FS) was administered, rats received an intraperitoneal injection of Eukarion (EUK-134), which mimics the activities of superoxide dismutase and catalase. Intact muscles of the hindlimbs were electrically stimulated via the sciatic nerve until the force was reduced to ~50% of the initial force (FS). Thirty minutes after cessation of FS, the superficial regions of gastrocnemius muscles were dissected and used for biochemical and skinned-fiber analyses. Whole muscle analyses revealed that antioxidant alleviated the FS-induced decrease in the reduced glutathione content. Skinned-fiber analyses showed that the antioxidant did not affect the FS-induced decrease in the ratio of force at 1 Hz to that at 50 Hz. However, the antioxidant partially inhibited the FS-mediated decrease in the ratio of depolarization-induced force to the maximum Ca2+-activated force. Furthermore, the antioxidant completely suppressed the FS-induced increase in myofibrillar Ca2+ sensitivity. These results suggest that antioxidant treatment is ineffective in facilitating the restoration of PLFFD, probably due to its negative effect on myofibrillar Ca2+ sensitivity, which supersedes its positive effect on SR Ca2+ release.
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Affiliation(s)
- Daiki Watanabe
- Department of Engineering Science, University of Electro-Communication, Tokyo, Japan
| | - Chihiro Aibara
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Hiroshima, Japan
| | - Masanobu Wada
- Graduate School of Integrated Arts and Sciences, Hiroshima University, Hiroshima, Japan
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Nogueira L, Trisko BM, Lima‐Rosa FL, Jackson J, Lund‐Palau H, Yamaguchi M, Breen EC. Cigarette smoke directly impairs skeletal muscle function through capillary regression and altered myofibre calcium kinetics in mice. J Physiol 2018; 596:2901-2916. [PMID: 29797443 PMCID: PMC6046067 DOI: 10.1113/jp275888] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 04/18/2018] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS Cigarette smoke components directly alter muscle fatigue resistance and intracellular muscle fibre Ca2+ handling independent of a change in lung structure. Changes in muscle vascular structure are associated with a depletion of satellite cells. Sarcoplasmic reticulum Ca2+ uptake is substantially impaired in myofibres during fatiguing contractions in mice treated with cigarette smoke extract. ABSTRACT Cigarette smokers exhibit exercise intolerance before a decline in respiratory function. In the present study, the direct effects of cigarette smoke on limb muscle function were tested by comparing cigarette smoke delivered to mice by weekly injections of cigarette smoke extract (CSE), or nose-only exposure (CS) 5 days each week, for 8 weeks. Cigarette smoke delivered by either route did not alter pulmonary airspace size. Muscle fatigue measured in situ was 50% lower in the CSE and CS groups than in control. This was accompanied by 34% and 22% decreases in soleus capillary-to-fibre ratio of the CSE and CS groups, respectively, and a trend for fewer skeletal muscle actin-positive arterioles (P = 0.07). In addition, fewer quiescent satellite cells (Nes+Pax7+) were associated with soleus fibres in mice with skeletal myofibre VEGF gene deletion (decreased 47%) and CS exposed (decreased 73%) than with control fibres. Contractile properties of isolated extensor digitorum longus and soleus muscles were impaired. In flexor digitorum brevis myofibres isolated from CSE mice, fatigue resistance was diminished by 43% compared to control and CS myofibres, and this was accompanied by a pronounced slowing in relaxation, an increase in intracellular Ca2+ accumulation, and a slowing in sarcoplasmic reticulum Ca2+ uptake. These data suggest that cigarette smoke components may impair hindlimb muscle vascular structure, fatigue resistance and myofibre calcium handling, and these changes ultimately affect contractile efficiency of locomotor muscles independent of a change in lung function.
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Affiliation(s)
- Leonardo Nogueira
- Department of MedicineUniversity of California, San DiegoLa JollaCAUSA
- Instituto de Bioquímica Médica Leopoldo de Meis (IBqM‐LDM)Universidade Federal do Rio de JaneiroRio de JaneiroRJBrazil
| | - Breanna M. Trisko
- Department of MedicineUniversity of California, San DiegoLa JollaCAUSA
| | - Frederico L. Lima‐Rosa
- Instituto de Bioquímica Médica Leopoldo de Meis (IBqM‐LDM)Universidade Federal do Rio de JaneiroRio de JaneiroRJBrazil
| | - Jason Jackson
- Department of MedicineUniversity of California, San DiegoLa JollaCAUSA
| | - Helena Lund‐Palau
- Department of MedicineUniversity of California, San DiegoLa JollaCAUSA
| | - Masahiro Yamaguchi
- Department of Physiology, Kochi Medical SchoolKochi UniversityKochiJapan
| | - Ellen C. Breen
- Department of MedicineUniversity of California, San DiegoLa JollaCAUSA
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