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Oberoi A, Giezenaar C, Rigda RS, Horowitz M, Jones KL, Chapman I, Soenen S. Effects of co-ingesting glucose and whey protein on blood glucose, plasma insulin and glucagon concentrations, and gastric emptying, in older men with and without type 2 diabetes. Diabetes Obes Metab 2023; 25:1321-1330. [PMID: 36694303 DOI: 10.1111/dom.14983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 01/19/2023] [Accepted: 01/22/2023] [Indexed: 01/26/2023]
Abstract
AIM To investigate whether co-ingestion of dietary protein with, or before, carbohydrate may be a useful strategy to reduce postprandial hyperglycaemia in older men with type 2 diabetes (T2D). MATERIALS AND METHODS Blood glucose, plasma insulin and glucagon concentrations were measured for 180 minutes following ingestion of a drink containing 30 g of glucose (G; 120 kcal), 30 g of whey protein (120 kcal), 30 g of glucose plus 30 g of whey protein (GP; 240 kcal), or control (~2 kcal) in older men with T2D (n = 10, 77 ± 1 years; 31 ± 1.7 kg/m2 ) and without T2D (n = 10, 78 ± 2 years; 27 ± 1.4 kg/m2 ). Mixed model analysis was used. RESULTS GP versus G markedly reduced the increase in blood glucose concentrations (P < .001) and had a synergistic effect on the increase in insulin concentrations (P < .001), in men both with and without T2D. Glucose concentrations were higher in men with T2D compared with those without T2D, whereas insulin and glucagon concentrations were largely unaffected by the presence of T2D. Gastric emptying was faster in men with T2D than in those without T2D. CONCLUSIONS The ability of whey protein to reduce carbohydrate-induced, postprandial hyperglycaemia is retained in older men with T2D compared with those without T2D, and whey protein supplementation may be a useful strategy in the prevention and management of T2D in older people.
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Affiliation(s)
- Avneet Oberoi
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Caroline Giezenaar
- Food Experience and Sensory Testing (FEAST) Laboratory, School of Food & Advanced Technology, Massey University, Palmerston North, New Zealand
| | - Rachael S Rigda
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Michael Horowitz
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Royal Adelaide Hospital, Adelaide, South Australia, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Karen L Jones
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Royal Adelaide Hospital, Adelaide, South Australia, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Ian Chapman
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Royal Adelaide Hospital, Adelaide, South Australia, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Stijn Soenen
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Royal Adelaide Hospital, Adelaide, South Australia, Australia
- Faculty of Health Sciences & Medicine, Bond University, Gold Coast, Queensland, Australia
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Comparative Effects of Co-Ingesting Whey Protein and Glucose Alone and Combined on Blood Glucose, Plasma Insulin and Glucagon Concentrations in Younger and Older Men. Nutrients 2022; 14:nu14153111. [PMID: 35956288 PMCID: PMC9370714 DOI: 10.3390/nu14153111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 07/25/2022] [Accepted: 07/26/2022] [Indexed: 12/10/2022] Open
Abstract
The ingestion of dietary protein with, or before, carbohydrate may be a useful strategy to reduce postprandial hyperglycemia, but its effect in older people, who have an increased predisposition for type 2 diabetes, has not been clarified. Blood glucose, plasma insulin and glucagon concentrations were measured for 180 min following a drink containing either glucose (120 kcal), whey-protein (120 kcal), whey-protein plus glucose (240 kcal) or control (~2 kcal) in healthy younger (n = 10, 29 ± 2 years; 26.1 ± 0.4 kg/m2) and older men (n = 10, 78 ± 2 years; 27.3 ± 1.4 kg/m2). Mixed model analysis was used. In both age groups the co-ingestion of protein with glucose (i) markedly reduced the increase in blood glucose concentrations following glucose ingestion alone (p < 0.001) and (ii) had a synergistic effect on the increase in insulin concentrations (p = 0.002). Peak insulin concentrations after protein were unaffected by ageing, whereas insulin levels after glucose were lower in older than younger men (p < 0.05) and peak insulin concentrations were higher after glucose than protein in younger (p < 0.001) but not older men. Glucagon concentrations were unaffected by age. We conclude that the ability of whey-protein to reduce carbohydrate-induced postprandial hyperglycemia is retained in older men and that protein supplementation may be a useful strategy in the prevention and management of type 2 diabetes in older people.
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Fan J, Yuan Z, Burley SK, Libutti SK, Zheng XFS. Amino acids control blood glucose levels through mTOR signaling. Eur J Cell Biol 2022; 101:151240. [PMID: 35623230 PMCID: PMC10035058 DOI: 10.1016/j.ejcb.2022.151240] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/15/2022] [Accepted: 05/16/2022] [Indexed: 12/12/2022] Open
Abstract
Amino Acids are not only major nutrient sources, but also serve as chemical signals to control cellular growth. Rab1A recently emerged as a key component in amino acid sensing and signaling to activate the mTOR complex1 (mTORC1). In a recently published study [1], we generated tamoxifen-inducible, conditional whole-body Rab1A knockout in adult mice. These mice are viable but develop hyperglycemia and glucose intolerance. Interestingly, Rab1A ablation selectively reduces insulin expression and pancreatic beta-cell population. Mechanistically, branched chain amino acids (BCAA), through the Rab1A-mTORC1 complex, promote the stability and nuclear localization of Pdx1, a master transcription factor that controls growth, function and identity of pancreatic beta-cells. These findings reveal a role and underlying mechanism by which amino acids control body's glucose level through a beta-cell specific function by the Rab1A-mTORC1-Pdx1 signaling axis, which has implications in both diabetes and cancer.
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Affiliation(s)
- Jialin Fan
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA; Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, 675 Hoes Lane, Piscataway, NJ 08854, USA
| | - Ziqiang Yuan
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA; Department of Surgery, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - Stephen K Burley
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA; RCSB Protein Data Bank and Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854, USA; Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854, USA; RCSB Protein Data Bank, San Diego Supercomputer Center, University of California, La Jolla, 9500 Gilman Drive, San Diego, CA 92093, USA
| | - Steven K Libutti
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA; Department of Surgery, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - X F Steven Zheng
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA; Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, 675 Hoes Lane, Piscataway, NJ 08854, USA.
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Gehring J, Azzout-Marniche D, Chaumontet C, Piedcoq J, Gaudichon C, Even PC. Rats Self-Select a Constant Protein-to-Carbohydrate Ratio Rather Than a Constant Protein-to-Energy Ratio and Have Low Plasma FGF21 Concentrations. J Nutr 2021; 151:1921-1936. [PMID: 33830241 DOI: 10.1093/jn/nxab056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/12/2021] [Accepted: 02/11/2021] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Under dietary self-selection (DSS), rats ingest 25-30% of energy as protein. This high level appears to be explained by metabolic benefits related to reduced carbohydrate dependence and associated pathologies. However, the mechanisms underlying these choices remain largely misunderstood. OBJECTIVES The aim was to test the hypothesis that in a DSS model, rats select a protein-to-energy (PE) ratio to maintain the protein-to-carbohydrate (PC) ratio constant and that fibroblast growth factor 21 (FGF21) is involved in this response. METHODS Adult male Wistar rats were used in 3 experiments. The first was to determine whether the PE ratio was influenced by changes in carbohydrate content. The second was to test whether the PE ratio was defended with a modified DSS model. The third was to determine whether the selected PE ratio was of metabolic interest compared with a standard 15% protein diet. Food intake, body weight, and energy expenditure were measured. After 3 wk, plasma was sampled and rats were killed to determine body composition and gene expression. Statistical analyses were mainly done by ANOVA tests and correlation tests. RESULTS The selected PE ratio increased from 20% to 35% when the carbohydrate content of the protein-free diet increased from 30% to 75% (R2 = 0.56; P < 10-6). Consequently, the PC ratio was constant (70%) in all groups (P = 0.18). In self-selecting rats, plasma FGF21 concentrations were 3 times lower than in rats fed the 5% protein diet (P < 10-4) and similar to those in rats fed a 30% diet. CONCLUSIONS This study showed that self-selecting rats established PE ratios larger than those considered sufficient to achieve optimal growth in adult rats (10-15%), and the ratios were highly dependent on carbohydrates, apparently with the aim of maintaining a constant and high PC ratio. This was associated with a minimization of plasma FGF21.
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Affiliation(s)
- Josephine Gehring
- Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, Paris, France
| | | | | | - Julien Piedcoq
- Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, Paris, France
| | - Claire Gaudichon
- Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, Paris, France
| | - Patrick C Even
- Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, Paris, France
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Zhang X, Wang X, Yuan Z, Radford SJ, Liu C, Libutti SK, Zheng XFS. Amino acids-Rab1A-mTORC1 signaling controls whole-body glucose homeostasis. Cell Rep 2021; 34:108830. [PMID: 33730578 PMCID: PMC8062038 DOI: 10.1016/j.celrep.2021.108830] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 12/28/2020] [Accepted: 02/16/2021] [Indexed: 12/17/2022] Open
Abstract
Rab1A is a small GTPase known for its role in vesicular trafficking. Recent evidence indicates that Rab1A is essential for amino acids (aas) sensing and signaling to regulate mTORC1 in normal and cancer cells. However, Rab1A's in vivo function in mammals is not known. Here, we report the generation of tamoxifen (TAM)-induced whole body Rab1A knockout (Rab1A-/-) in adult mice. Rab1A-/- mice are viable but become hyperglycemic and glucose intolerant due to impaired insulin transcription and β-cell proliferation and maintenance. Mechanistically, Rab1A mediates AA-mTORC1 signaling, particularly branched chain amino acids (BCAA), to regulate the stability and localization of the insulin transcription factor Pdx1. Collectively, these results reveal a physiological role of aa-Rab1A-mTORC1 signaling in the control of whole-body glucose homeostasis in mammals. Intriguingly, Rab1A expression is reduced in β-cells of type 2 diabetes (T2D) patients, which is correlated with loss of insulin expression, suggesting that Rab1A downregulation contributes to T2D progression.
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Affiliation(s)
- Xin Zhang
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA; Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, 675 Hoes Lane, Piscataway, NJ 08854, USA
| | - Xiaowen Wang
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA; Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, 675 Hoes Lane, Piscataway, NJ 08854, USA
| | - Ziqiang Yuan
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA; Department of Surgery, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - Sarah J Radford
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - Chen Liu
- Department of Pathology and Laboratory Medicine, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - Steven K Libutti
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA; Department of Surgery, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA
| | - X F Steven Zheng
- Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA; Department of Pharmacology, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, 675 Hoes Lane, Piscataway, NJ 08854, USA.
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Ancu O, Mickute M, Guess ND, Hurren NM, Burd NA, Mackenzie RW. Does high dietary protein intake contribute to the increased risk of developing prediabetes and type 2 diabetes? Appl Physiol Nutr Metab 2020; 46:1-9. [PMID: 32755490 DOI: 10.1139/apnm-2020-0396] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Insulin resistance is a complex metabolic disorder implicated in the development of many chronic diseases. While it is generally accepted that body mass loss should be the primary approach for the management of insulin resistance-related disorders in overweight and obese individuals, there is no consensus among researchers regarding optimal protein intake during dietary restriction. Recently, it has been suggested that increased plasma branched-chain amino acids concentrations are associated with the development of insulin resistance and type 2 diabetes. The exact mechanism by which excessive amino acid availability may contribute to insulin resistance has not been fully investigated. However, it has been hypothesised that mammalian target of rapamycin (mTOR) complex 1 hyperactivation in the presence of amino acid overload contributes to reduced insulin-stimulated glucose uptake because of insulin receptor substrate (IRS) degradation and reduced Akt-AS160 activity. In addition, the long-term effects of high-protein diets on insulin sensitivity during both weight-stable and weight-loss conditions require more research. This review focusses on the effects of high-protein diets on insulin sensitivity and discusses the potential mechanisms by which dietary amino acids can affect insulin signalling. Novelty: Excess amino acids may over-activate mTOR, resulting in desensitisation of IRS-1 and reduced insulin-mediated glucose uptake.
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Affiliation(s)
- Oana Ancu
- Department of Life Sciences, University of Roehampton, London SW15 4DJ, UK
| | - Monika Mickute
- Diabetes Research Centre, University of Leicester and the NIHR Leicester Biomedical Research Centre, Leicester, LE17RH, UK
| | - Nicola D Guess
- Department of Nutritional Sciences, King's College London, London, WC2R2LS, UK
| | - Nicholas M Hurren
- Department of Life Sciences, University of Roehampton, London SW15 4DJ, UK
| | - Nicholas A Burd
- Division of Nutritional Sciences, University of Illinois, Urbana, IL 61820, USA
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7
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Caloric restriction induces anabolic resistance to resistance exercise. Eur J Appl Physiol 2020; 120:1155-1164. [PMID: 32236752 PMCID: PMC8233264 DOI: 10.1007/s00421-020-04354-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 03/21/2020] [Indexed: 12/21/2022]
Abstract
Purpose Weight loss can result in the loss of muscle mass and bone mineral density. Resistance exercise is commonly prescribed to attenuate these effects. However, the anabolic endocrine response to resistance exercise during caloric restriction has not been characterized. Methods Participants underwent 3-day conditions of caloric restriction (15 kcal kg FFM−1) with post-exercise carbohydrate (CRC) and with post-exercise protein (CRP), and an energy balance control (40 kcal kg FFM−1) with post-exercise carbohydrate (CON). Serial blood draws were taken following five sets of five repetitions of the barbell back squat exercise on day 3 of each condition. Results In CRC and CRP, respectively, growth hormone peaked at 2.6 ± 0.4 and 2.5 ± 0.9 times the peak concentrations observed during CON. Despite this, insulin-like growth factor-1 concentrations declined 18.3 ± 3.4% in CRC and 27.2 ± 3.8% in CRP, which was greater than the 7.6 ± 3.6% decline in CON, over the subsequent 24 h. Sclerostin increased over the first 2 days of each intervention by 19.2 ± 5.6% in CRC, 21.8 ± 6.2% in CRP and 13.4 ± 5.9% in CON, but following the resistance exercise bout, these increases were attenuated and no longer significant. Conclusion During caloric restriction, there is considerable endocrine anabolic resistance to a single bout of resistance exercise which persists in the presence of post-exercise whey protein supplementation. Alternative strategies to restore the sensitivity of insulin-like growth factor-1 to growth hormone need to be explored. Electronic supplementary material The online version of this article (10.1007/s00421-020-04354-0) contains supplementary material, which is available to authorized users.
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Myette-Côté É, Baba K, Brar R, Little JP. Detection of Salivary Insulin Following Low versus High Carbohydrate Meals in Humans. Nutrients 2017; 9:nu9111204. [PMID: 29099048 PMCID: PMC5707676 DOI: 10.3390/nu9111204] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 10/26/2017] [Accepted: 10/29/2017] [Indexed: 01/18/2023] Open
Abstract
Developing non-invasive alternatives to monitor insulin levels in humans holds potential practical value for identifying individuals with, or at risk of developing, insulin resistance. The aims of this study were: (1) to determine if saliva insulin can be used to delineate between low and high postprandial insulin levels following the ingestion of mixed breakfast meals; and (2) to determine if expected differences in postprandial hyperinsulinemia between young lean and young overweight/obese participants could be detected in saliva. Sixteen individuals (n = 8 classified as normal weight (NW); BMI 20.0–24.9 kg/m2, and n = 8 classified as overweight/obese (OO); BMI ≥ 28.0 kg/m2) completed two isocaloric mixed-meal tolerance tests following an overnight fast, consisting of a low-carbohydrate (LC) breakfast or a high-carbohydrate (HC) breakfast. Blood and saliva samples were collected at regular intervals for two hours postprandially. In both groups, plasma and saliva insulin total area under the curve (AUC) and incremental AUC (iAUC) were significantly higher after the HC as compared to the LC meal (all p ≤ 0.005). Insulin AUC and iAUC in both plasma and saliva were higher in OO than in NW after the HC meal (all p ≤ 0.02) but only plasma and saliva total AUC were higher in OO after the LC meal (both p ≤ 0.01). Plasma insulin AUC was significantly correlated with salivary insulin AUC in LC (r = 0.821; p < 0.001) and HC (r = 0.882; p < 0.001). These findings indicate that saliva could potentially be used to delineate between low and high insulin levels following mixed breakfast meals.
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Affiliation(s)
- Étienne Myette-Côté
- School of Health and Exercise Sciences, University of British Columbia Okanagan, 3333 University Way, Kelowna, BC V1V 1V7, Canada.
| | - Katie Baba
- Southern Medical Program, University of British Columbia Okanagan, 3333 University Way, Kelowna, BC V1V 1V7, Canada.
| | - Raj Brar
- Southern Medical Program, University of British Columbia Okanagan, 3333 University Way, Kelowna, BC V1V 1V7, Canada.
| | - Jonathan Peter Little
- School of Health and Exercise Sciences, University of British Columbia Okanagan, 3333 University Way, Kelowna, BC V1V 1V7, Canada.
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Horiuchi M, Takeda T, Takanashi H, Ozaki-Masuzawa Y, Taguchi Y, Toyoshima Y, Otani L, Kato H, Sone-Yonezawa M, Hakuno F, Takahashi SI, Takenaka A. Branched-chain amino acid supplementation restores reduced insulinotropic activity of a low-protein diet through the vagus nerve in rats. Nutr Metab (Lond) 2017; 14:59. [PMID: 28932254 PMCID: PMC5602936 DOI: 10.1186/s12986-017-0215-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 09/05/2017] [Indexed: 02/09/2023] Open
Abstract
Background Previously, we reported that a low-protein diet significantly reduced insulin secretion in response to feeding within 1 h in rats, suggesting that the insulinotropic effect of dietary protein plays an important role in maintaining normal insulin release. The current study aimed to elucidate whether deficiency of certain amino acids could diminish the insulinotropic activity and to investigate whether reduced insulin secretion in response to a low-protein diet is restored by supplementation with certain amino acids. Methods First, we fed male Wistar rats (5–6 rats per group) with diets deficient in every single amino acid or three branched-chain amino acids (BCAAs); within 1–2 h after the onset of feeding, we measured the plasma insulin levels by using an enzyme-linked immunosorbent assay (ELISA). As insulin secretion was reduced in BCAA-deficient groups, we fed low-protein diets supplemented with BCAAs to assess whether the reduced insulin secretion was restored. In addition, we treated the pancreatic beta cell line MIN6 with BCAAs to investigate the direct insulinotropic activity on beta cells. Lastly, we investigated the effect of the three BCAAs on sham-operated or vagotomized rats to assess involvement of the vagus nerve in restoration of the insulinotropic activity. Results Feeding a low-protein diet reduced essential amino acid concentrations in the plasma during an absorptive state, suggesting that reduced plasma amino acid levels can be an initial signal of protein deficiency. In normal rats, insulin secretion was reduced when leucine, valine, or three BCAAs were deficient. Insulin secretion was restored to normal levels by supplementation of the low-protein diet with three BCAAs, but not by supplementation with any single BCAA. In MIN6 cells, each BCAA alone stimulated insulin secretion but the three BCAAs did not show a synergistic stimulatory effect. The three BCAAs showed a synergistic stimulatory effect in sham-operated rats but failed to stimulate insulin secretion in vagotomized rats. Conclusions Leucine and valine play a role in maintaining normal insulin release by directly stimulating beta cells, and supplementation with the three BCAAs is sufficient to compensate for the reduced insulinotropic activity of the low-protein diet, through the vagus nerve.
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Affiliation(s)
- Mami Horiuchi
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, Kanagawa, Japan
| | - Tomoya Takeda
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, Kanagawa, Japan
| | - Hiroyuki Takanashi
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, Kanagawa, Japan
| | - Yori Ozaki-Masuzawa
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, Kanagawa, Japan.,Department of Chemistry and Life Science, College of Bioresource Sciences, Nihon University, Kanagawa, Japan
| | - Yusuke Taguchi
- Institute for Advanced Medical Sciences, Nippon Medical School, Kanagawa, Japan
| | - Yuka Toyoshima
- Institute for Advanced Medical Sciences, Nippon Medical School, Kanagawa, Japan
| | - Lila Otani
- Corporate Sponsored Research Program "Food for Life" Organization for Interdisciplinary Research Projects, The University of Tokyo, Tokyo, Japan
| | - Hisanori Kato
- Corporate Sponsored Research Program "Food for Life" Organization for Interdisciplinary Research Projects, The University of Tokyo, Tokyo, Japan
| | - Meri Sone-Yonezawa
- Department of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Fumihiko Hakuno
- Department of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Shin-Ichiro Takahashi
- Department of Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Asako Takenaka
- Department of Agricultural Chemistry, School of Agriculture, Meiji University, Kanagawa, Japan
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Gentle HL, Love TD, Howe AS, Black KE. A randomised trial of pre-exercise meal composition on performance and muscle damage in well-trained basketball players. J Int Soc Sports Nutr 2014; 11:33. [PMID: 25053925 PMCID: PMC4105559 DOI: 10.1186/1550-2783-11-33] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 06/20/2014] [Indexed: 11/12/2022] Open
Abstract
Background Attenuating muscle damage is important to subsequent sports performance. It is possible that pre-exercise protein intake could influence markers of muscle damage and benefit performance, however, published research provides conflicting results. At present no study has investigated protein and carbohydrate (PRO/CHO) co-ingestion solely pre-exercise, nor prior to basketball-specific exercise. The purpose of this study was to answer the research question; would pre-exercise protein intake enhance performance or attenuate muscle damage during a basketball simulation test? Methods Ten well-trained male basketball players consumed either carbohydrate (1 g · kg−1 body mass) with protein (1 g · kg−1 body mass), or carbohydrate alone (2 g · kg−1 body mass) in a randomised cross- over design, 90 minutes before completing an 87-minute exercise protocol. Results The rise in creatine kinase (CK) from baseline to post-exercise was attenuated following PRO/CHO (56 ± 13U · L−1) compared to carbohydrate (100 ± 10 U · L−1), (p = 0.018). Blood glucose was also higher during and post-exercise following PRO/CHO (p < 0.050), as was free throw shooting accuracy in the fourth quarter (p = 0.027). Nausea during (p = 0.007) and post-(p = 0.039) exercise increased following PRO/CHO, as did cortisol post-exercise (p = 0.038). Conclusions Results suggest that in well-trained basketball players, pre-exercise PRO/CHO may attenuate the rise in CK, indicative of a decrease in muscle damage during exercise. However, unfamiliarity with the protein amount provided may have increased nausea during exercise, and this may have limited the ability to see an improvement in more performance measures.
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Affiliation(s)
- Hannah Lonika Gentle
- Department of Human Nutrition, University of Otago, P.O. Box 56, 9054 Dunedin, New Zealand
| | - Thomas Darrell Love
- Applied Sports Technology Exercise and Medicine Research Centre Sport & Exercise Science College of Engineering, Swansea University, Room 955 Talbot Building, SA2 8PP Swansea, Wales
| | - Anna Susan Howe
- Department of Human Nutrition, University of Otago, P.O. Box 56, 9054 Dunedin, New Zealand
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Moazzami AA, Shrestha A, Morrison DA, Poutanen K, Mykkänen H. Metabolomics reveals differences in postprandial responses to breads and fasting metabolic characteristics associated with postprandial insulin demand in postmenopausal women. J Nutr 2014; 144:807-14. [PMID: 24717363 DOI: 10.3945/jn.113.188912] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Changes in serum metabolic profile after the intake of different food products (e.g., bread) can provide insight into their interaction with human metabolism. Postprandial metabolic responses were compared after the intake of refined wheat (RWB), whole-meal rye (WRB), and refined rye (RRB) breads. In addition, associations between the metabolic profile in fasting serum and the postprandial concentration of insulin in response to different breads were investigated. Nineteen postmenopausal women with normal fasting glucose and normal glucose tolerance participated in a randomized, controlled, crossover meal study. The test breads, RWB (control), RRB, and WRB, providing 50 g of available carbohydrate, were each served as a single meal. The postprandial metabolic profile was measured using nuclear magnetic resonance and targeted LC-mass spectrometry and was compared between different breads using ANOVA and multivariate models. Eight amino acids had a significant treatment effect (P < 0.01) and a significant treatment × time effect (P < 0.05). RWB produced higher postprandial concentrations of leucine (geometric mean: 224; 95% CI: 196, 257) and isoleucine (mean ± SD: 111 ± 31.5) compared with RRB (geometric mean: 165; 95% CI: 147, 186; mean ± SD: 84.2 ± 22.9) and WRB (geometric mean: 190; 95% CI: 174, 207; mean ± SD: 95.8 ± 17.3) at 60 min respectively (P < 0.001). In addition, 2 metabolic subgroups were identified using multivariate models based on the association between fasting metabolic profile and the postprandial concentration of insulin. Women with higher fasting concentrations of leucine and isoleucine and lower fasting concentrations of sphingomyelins and phosphatidylcholines had higher insulin responses despite similar glucose concentration after all kinds of bread (cross-validated ANOVA, P = 0.048). High blood concentration of branched-chain amino acids, i.e., leucine and isoleucine, has been associated with the increased risk of diabetes, which suggests that additional consideration should be given to bread proteins in understanding the beneficial health effects of different kinds of breads. The present study suggests that the fasting metabolic profile can be used to characterize the postprandial insulin demand in individuals with normal glucose metabolism that can be used for establishing strategies for the stratification of individuals in personalized nutrition.
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Affiliation(s)
| | | | - David A Morrison
- Biomedical Science and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Kaisa Poutanen
- Institute of Public Health and Clinical Nutrition, Department of Clinical Nutrition, University of Eastern Finland, Kuopio, Finland; and VTT Technical Research Centre of Finland, Espoo, Finland
| | - Hannu Mykkänen
- Institute of Public Health and Clinical Nutrition, Department of Clinical Nutrition, University of Eastern Finland, Kuopio, Finland; and
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12
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Zhang J, Xue C, Zhu T, Vivekanandan A, Pennathur S, Ma ZA, Chen YE. A tripeptide Diapin effectively lowers blood glucose levels in male type 2 diabetes mice by increasing blood levels of insulin and GLP-1. PLoS One 2013; 8:e83509. [PMID: 24386218 PMCID: PMC3873933 DOI: 10.1371/journal.pone.0083509] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Accepted: 11/04/2013] [Indexed: 01/28/2023] Open
Abstract
The prevalence of type 2 diabetes (T2D) is rapidly increasing worldwide. Effective therapies, such as insulin and Glucagon-like peptide-1 (GLP-1), require injections, which are costly and result in less patient compliance. Here, we report the identification of a tripeptide with significant potential to treat T2D. The peptide, referred to as Diapin, is comprised of three natural L-amino acids, GlyGlyLeu. Glucose tolerance tests showed that oral administration of Diapin effectively lowered blood glucose after oral glucose loading in both normal C57BL/6J mice and T2D mouse models, including KKay, db/db, ob/ob mice, and high fat diet-induced obesity/T2D mice. In addition, Diapin treatment significantly reduced casual blood glucose in KKay diabetic mice in a time-dependent manner without causing hypoglycemia. Furthermore, we found that plasma GLP-1 and insulin levels in diabetic models were significantly increased with Diapin treatment compared to that in the controls. In summary, our findings establish that a peptide with minimum of three amino acids can improve glucose homeostasis and Diapin shows promise as a novel pharmaceutical agent to treat patients with T2D through its dual effects on GLP-1 and insulin secretion.
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Affiliation(s)
- Jifeng Zhang
- Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Changyong Xue
- Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Tianqing Zhu
- Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Anuradha Vivekanandan
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Subramaniam Pennathur
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
| | - Zhongmin Alex Ma
- Diapin Therapeutics Limited Liability Company, Ann Arbor, Michigan, United States of America
| | - Y. Eugene Chen
- Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan, United States of America
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13
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Russell WR, Baka A, Björck I, Delzenne N, Gao D, Griffiths HR, Hadjilucas E, Juvonen K, Lahtinen S, Lansink M, Loon LV, Mykkänen H, östman E, Riccardi G, Vinoy S, Weickert MO. Impact of Diet Composition on Blood Glucose Regulation. Crit Rev Food Sci Nutr 2013; 56:541-90. [DOI: 10.1080/10408398.2013.792772] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Wendy R. Russell
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | | | - Inger Björck
- Centre for Chemistry and Chemical Engineering, University of Lund, Lund, Sweden
| | - Nathalie Delzenne
- Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Dan Gao
- Department of Diabetes and Metabolic Diseases, Beckman Research Institute of City of Hope, Duarte, California, USA
| | | | - Ellie Hadjilucas
- Coca-Cola Europe, Scientific and Regulatory Affairs Department, Brussels, Belgium
| | - Kristiina Juvonen
- Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
| | | | - Mirian Lansink
- Danone Research, Centre for Specialised Nutrition, Wageningen, The Netherlands
| | - Luc Van Loon
- Department of Movement Sciences, Maastricht University, Maastricht, The Netherlands
| | - Hannu Mykkänen
- Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
| | - Elin östman
- Centre for Chemistry and Chemical Engineering, University of Lund, Lund, Sweden
| | - Gabriele Riccardi
- Department of Clinical and Experimental Medicine, University Federico II, Naples, Italy
| | - Sophie Vinoy
- Kraft Foods, R&D Centre, Nutrition Department, Saclay, France
| | - Martin O. Weickert
- University Hospitals Coventry and Warwickshire and Division of Metabolic and Vascular Health, University of Warwick, Coventry, UK
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Insulinotropic and muscle protein synthetic effects of branched-chain amino acids: potential therapy for type 2 diabetes and sarcopenia. Nutrients 2012. [PMID: 23201839 PMCID: PMC3509512 DOI: 10.3390/nu4111664] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The loss of muscle mass and strength with aging (i.e., sarcopenia) has a negative effect on functional independence and overall quality of life. One main contributing factor to sarcopenia is the reduced ability to increase skeletal muscle protein synthesis in response to habitual feeding, possibly due to a reduction in postprandial insulin release and an increase in insulin resistance. Branched-chain amino acids (BCAA), primarily leucine, increases the activation of pathways involved in muscle protein synthesis through insulin-dependent and independent mechanisms, which may help counteract the "anabolic resistance" to feeding in older adults. Leucine exhibits strong insulinotropic characteristics, which may increase amino acid availability for muscle protein synthesis, reduce muscle protein breakdown, and enhance glucose disposal to help maintain blood glucose homeostasis.
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Hara D, Morrison PJ, Ding Z, Ivy JL. Effect of carbohydrate-protein supplementation postexercise on rat muscle glycogen synthesis and phosphorylation of proteins controlling glucose storage. Metabolism 2011; 60:1406-15. [PMID: 21489581 DOI: 10.1016/j.metabol.2011.02.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 02/08/2011] [Accepted: 02/10/2011] [Indexed: 11/16/2022]
Abstract
To examine whether addition of protein to a carbohydrate supplement enhances muscle glycogen synthesis, we compared the muscle glycogen concentrations of rats that had been depleted of their muscle glycogen stores with a 3-hour swim and immediately supplemented with a placebo (Con), carbohydrate (CHO), or carbohydrate plus protein supplement (C+P). Rats were given either 0.9 g carbohydrate per kilogram body mass for the CHO group or 0.9 g carbohydrate + 0.3 g protein per kilogram body mass for the C+P groups. Muscle samples of the red and white quadriceps were excised immediately, 30 minutes, or 90 minutes postexercise. Glycogen concentration of the C+P group was greater than that of the CHO group at 90 minutes postexercise in both red (C+P, 28.3 ± 2.6 µmol/g vs CHO, 22.4 ± 2.0 µmol/g; P < .05) and white (C+P, 24.9 ± 2.4 µmol/g vs CHO, 17.64 ± 1.5 µmol/g; P < .01) quadriceps. Protein kinase B phosphorylation was greater in the C+P-30 group (the number following treatment group abbreviation refers to time [in minutes] of euthanasia following exercise) than the sedentary control and exercised control groups in red quadriceps at 30 minutes and in white quadriceps at 90 minutes postexercise. This difference was not observed in the CHO group. Phosphorylation of glycogen synthase was significantly reduced 30 minutes postexercise and returned to baseline levels by 90 minutes postexercise in both CHO- and C+P-supplemented groups, with no difference between supplements. These results demonstrated that the addition of protein to a carbohydrate supplement will enhance the rate of muscle glycogen restoration postexercise and may involve facilitation of the glucose transport process.
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Affiliation(s)
- Daisuke Hara
- Exercise Physiology and Metabolism Laboratory, Department of Kinesiology and Health Education, University of Texas, Austin, TX 78712, USA
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Gannon MC, Nuttall FQ. Effect of a high-protein diet on ghrelin, growth hormone, and insulin-like growth factor-I and binding proteins 1 and 3 in subjects with type 2 diabetes mellitus. Metabolism 2011; 60:1300-11. [PMID: 21406307 DOI: 10.1016/j.metabol.2011.01.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 01/19/2011] [Accepted: 01/29/2011] [Indexed: 01/12/2023]
Abstract
We have developed a diet that over 5 weeks dramatically lowers plasma glucose in people with type 2 diabetes mellitus. This diet consists of 30% carbohydrate, 30% protein, and 40% fat and is referred to as a Low Biologically Available Glucose (LoBAG) diet. The diet also resulted in an approximately 30% increase in fasting insulin-like growth factor-I (IGF-I). Thus, we were interested in determining if the IGF-I elevation was due to an increase in ghrelin and growth hormone (GH) or to a change in IGF-I binding proteins (IGFBPs). Eight men with type 2 diabetes mellitus ingested a control diet (15% protein, 55% carbohydrate, and 30% fat) and a LoBAG(30) diet for 5 weeks in a randomized crossover design with a washout period in between. Before and after each 5-week period, subjects had blood drawn for total glycated hemoglobin and, at several time points over 24 hours, for GH, IGF-I, IGFBP-1, IGFBP-3, ghrelin, glucose, and insulin. Fasting and 24-hour glucose concentrations and total glycated hemoglobin were decreased, as expected (all Ps < .05). Fasting IGF-I increased by approximately 30% (P = .05) and remained unchanged throughout 24 hours. Ghrelin, GH, IGFBP-1, IGFBP-3, and insulin were not different between diets. Insulin and IGFBP-1 concentrations were reciprocal, as expected. Insulin-like growth factor-I binding protein 1 decreased as insulin increased to greater than approximately 30 to 40 μU/mL. Ingestion of a LoBAG(30) diet by weight-stable subjects with type 2 diabetes mellitus resulted in an increase in total IGF-I without an increase in ghrelin, GH, and IGFBP-3 or a change in IGFBP-1 regulation. The mechanism remains to be determined.
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Affiliation(s)
- Mary Carol Gannon
- Section of Endocrinology, Metabolism and Nutrition and the Metabolic Research Laboratory, Minneapolis VA Medical Center, Minneapolis, MN 55417, USA.
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Geerts BF, Dongen MGV, Flameling B, Moerland MM, Kam MLD, Cohen AF, Romijn JA, Gerhardt CC, Kloek J, Burggraaf J. Hydrolyzed Casein Decreases Postprandial Glucose Concentrations in T2DM Patients Irrespective of Leucine Content. J Diet Suppl 2011; 8:280-92. [DOI: 10.3109/19390211.2011.593617] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Breen L, Philp A, Shaw CS, Jeukendrup AE, Baar K, Tipton KD. Beneficial effects of resistance exercise on glycemic control are not further improved by protein ingestion. PLoS One 2011; 6:e20613. [PMID: 21701685 PMCID: PMC3119062 DOI: 10.1371/journal.pone.0020613] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 05/05/2011] [Indexed: 01/11/2023] Open
Abstract
Purpose To investigate the mechanisms underpinning modifications in glucose homeostasis and insulin sensitivity 24 h after a bout of resistance exercise (RE) with or without protein ingestion. Methods Twenty-four healthy males were assigned to a control (CON; n = 8), exercise (EX; n = 8) or exercise plus protein condition (EX+PRO; n = 8). Muscle biopsy and blood samples were obtained at rest for all groups and immediately post-RE (75% 1RM, 8×10 repetitions of leg-press and extension exercise) for EX and EX+PRO only. At 24 h post-RE (or post-resting biopsy for CON), a further muscle biopsy was obtained. Participants then consumed an oral glucose load (OGTT) containing 2 g of [U-13C] glucose during an infusion of 6, 6-[2H2] glucose. Blood samples were obtained every 10 min for 2 h to determine glucose kinetics. EX+PRO ingested an additional 25 g of intact whey protein with the OGTT. A final biopsy sample was obtained at the end of the OGTT. Results Fasted plasma glucose and insulin were similar for all groups and were not different immediately post- and 24 h post-RE. Following RE, muscle glycogen was 26±8 and 19±6% lower in EX and EX+PRO, respectively. During OGTT, plasma glucose AUC was lower for EX and EX+PRO (75.1±2.7 and 75.3±2.8 mmol·L−1∶120 min, respectively) compared with CON (90.6±4.1 mmol·L−1∶120 min). Plasma insulin response was 13±2 and 21±4% lower for EX and CON, respectively, compared with EX+PRO. Glucose disappearance from the circulation was ∼12% greater in EX and EX+PRO compared with CON. Basal 24 h post-RE and insulin-stimulated PAS-AS160/TBC1D4 phosphorylation was greater for EX and EX+PRO. Conclusions Prior RE improves glycemic control and insulin sensitivity through an increase in the rate at which glucose is disposed from the circulation. However, co-ingesting protein during a high-glucose load does not augment this response at 24 h post-exercise in healthy, insulin-sensitive individuals.
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Affiliation(s)
- Leigh Breen
- School of Sport and Exercise Sciences, University of Birmingham, Birmingham, United Kingdom
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Andrew Philp
- Functional Molecular Biology Lab, Neurobiology, Physiology and Behaviour, University of California Davis, Davis, California, United States of America
| | - Christopher S. Shaw
- School of Sport and Exercise Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Asker E. Jeukendrup
- School of Sport and Exercise Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Keith Baar
- Functional Molecular Biology Lab, Neurobiology, Physiology and Behaviour, University of California Davis, Davis, California, United States of America
| | - Kevin D. Tipton
- School of Sport and Exercise Sciences, University of Birmingham, Birmingham, United Kingdom
- Department of Sports Studies, University of Stirling, Stirling, United Kingdom
- * E-mail:
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19
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Growth hormone responses to ingestion of soyprotein with or without fat and/or carbohydrate in humans. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.eclnm.2009.06.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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van Vught AJAH, Nieuwenhuizen AG, Brummer RJM, Westerterp-Plantenga MS. Somatotropic responses to soy protein alone and as part of a meal. Eur J Endocrinol 2008; 159:15-8. [PMID: 18463106 DOI: 10.1530/eje-08-0142] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
CONTEXT GH is an important regulator of growth and body composition. We previously showed that GH release can be promoted by oral ingestion of soy protein; it is not known, however, whether these somatotropic effects of soy protein are also present when soy protein is ingested as part of a complete meal. OBJECTIVE/DESIGN We compared the effects of oral ingestion of soy protein alone with the effects of a meal containing the same amount of soy protein on GH secretion in six healthy women (body mass index 19-26 kg/m(2), 19-36 years), in a randomized crossover design. During the whole experiment, serum GH, insulin, and glucose were determined every 20 min. RESULTS GH responses as determined by area under the curve (AUC) and peak values were lower after ingestion of the meal, in comparison with GH responses after the soy protein consumption alone (P<0.05), and did not differ from the placebo. Glucose and insulin responses, both determined as AUC and peak values, were higher after ingestion of the meal, compared with those after ingestion of the protein drink or the placebo (P<0.05). CONCLUSION The somatotropic effect of soy protein is reduced and delayed when soy protein is ingested as part of a complete meal. Dietary carbohydrates, by increasing serum levels of glucose and insulin concentration, as well as dietary fat, may have interfered with the somatotropic effects of soy protein.
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Affiliation(s)
- Anneke J A H van Vught
- Department of Human Biology, PO Box 616, 6200 MD Maastricht, The Netherlands and TI Food and Nutrition, PO Box 557, 6700 AN Wageningen, The Netherlands.
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Manders RJ, Koopman R, Beelen M, Gijsen AP, Wodzig WK, Saris WH, van Loon LJ. The muscle protein synthetic response to carbohydrate and protein ingestion is not impaired in men with longstanding type 2 diabetes. J Nutr 2008; 138:1079-85. [PMID: 18492837 DOI: 10.1093/jn/138.6.1079] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Protein ingestion stimulates muscle protein synthesis and improves net muscle protein balance. Insulin resistance has been suggested to result in a reduced muscle protein synthetic response to food intake. As such, we hypothesized that type 2 diabetes patients have a impaired muscle protein synthetic response to food ingestion. To test this hypothesis, 10 male type 2 diabetes patients using their normal oral glucose-lowering medication (68 +/- 2 y) and 10 matched, normoglycemic men (65 +/- 2 y) were randomly assigned to 2 crossover treatments in which whole body and muscle protein synthesis were measured following the consumption of either carbohydrate (CHO) or carbohydrate with a protein hydrolysate (CHO+PRO). Primed, continuous infusions with L-[ring-13C6]phenylalanine and L-[ring-2H2]tyrosine were applied and blood and muscle samples were collected to assess whole-body protein balance and mixed muscle protein fractional synthetic rate over a 6-h period. Whole-body phenylalanine and tyrosine flux were higher after the CHO+PRO treatment compared with the CHO treatment in the diabetes and control group (P < 0.01). Protein balance was negative following CHO but positive following CHO+PRO treatment in both groups. Muscle protein synthesis rates were higher in both groups following the CHO+PRO (0.086 +/- 0.014%/h) treatment than in the CHO treatment (0.040 +/- 0.003%/h; P < 0.01) with no difference between the diabetes patients and normoglycemic controls. We conclude that the muscle protein synthetic response to CHO or CHO+PRO ingestion is not substantially impaired in longstanding, type 2 diabetes patients treated with oral blood glucose-lowering medication.
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Affiliation(s)
- Ralph J Manders
- Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht, Maastricht University, 6200 MD Maastricht, The Netherlands.
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van Vught AJAH, Nieuwenhuizen AG, Brummer RJM, Westerterp-Plantenga MS. Effects of oral ingestion of amino acids and proteins on the somatotropic axis. J Clin Endocrinol Metab 2008; 93:584-90. [PMID: 18029456 DOI: 10.1210/jc.2007-1784] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
CONTEXT GH is an important regulator of growth and body composition. It has been shown that GH release can be promoted by iv as well as oral administration of various amino acids (AAs), especially arginine (ARG) and lysine (LYS), which are amply present in soy protein. However, the effects of dietary protein on GH secretion are less well described. OBJECTIVE AND DESIGN In an experiment, we compared the effects of oral ingestion of a mixture reflecting the AA composition of soy protein (AA), with oral ingestion of ARG + LYS, on GH secretion in eight healthy women (body mass index 19-25 kg/m(2); age, 18-24 yr). In a second experiment, we compared oral ingestion of hydrolyzed soy protein and complete soy protein with the AA mixture on GH secretion in eight healthy women (body mass index 19-26 kg/m(2); age, 19-36 yr). Both experiments were performed in a randomized, single-blind crossover design. GH, insulin, glucose, and plasma AA were determined every 20 min, during 3 h in the first experiment and during 5 h in the second experiment. RESULTS Peak values of GH were higher after ingestion of the AA mixture compared with ingestion of ARG + LYS (P < 0.05). GH responses, as determined by area under the curve, did not significantly differ after ingestion of the complete soy protein, hydrolyzed soy protein, or AA mixture but were all higher than after placebo (P < 0.05). Insulin responses (area under the curve) were higher after ingestion of hydrolyzed soy protein, complete soy protein, and AA mixture, compared with placebo (P < 0.05). Glucose concentrations were unaffected. CONCLUSION Ingestion of soy protein, either hydrolyzed or intact, as well as AAs reflecting soy protein, stimulates GH release to a similar extent.
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Affiliation(s)
- Anneke J A H van Vught
- Department of Human Biology, University of Maastricht, P.O. Box 616, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands.
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Claessens M, Calame W, Siemensma AD, van Baak MA, Saris WHM. The effect of different protein hydrolysate/carbohydrate mixtures on postprandial glucagon and insulin responses in healthy subjects. Eur J Clin Nutr 2007; 63:48-56. [PMID: 17851462 DOI: 10.1038/sj.ejcn.1602896] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVES To study the effect of four protein hydrolysates from vegetable (pea, gluten, rice and soy) and two protein hydrolysates from animal origin (whey and egg) on glucagon and insulin responses. SUBJECTS/METHODS Eight healthy normal-weight male subjects participated in this study. The study employed a repeated-measures design with Latin square randomization and single-blind trials. Protein hydrolysates used in this study (pea, rice, soy, gluten, whey and egg protein hydrolysate) consisted of 0.2 g hydrolysate per kg body weight (bw) and 0.2 g maltodextrin per kg bw and were compared to maltodextrin alone. Postprandial plasma glucose, glucagon, insulin and amino acids were determined over 2 h. RESULTS All protein hydrolysates induced an enhanced insulin secretion compared to maltodextrin alone and a correspondingly low plasma glucose response. A significant difference was observed in area under the curve (AUC) for plasma glucagon between protein hydrolysates and the maltodextrin control drink (P<0.05). Gluten protein hydrolysate induced the lowest glucagon response. CONCLUSIONS High amino-acid-induced glucagon response does not necessarily go together with low insulin response. Protein hydrolysate source affects AUC for glucagon more profoundly than for insulin, although the protein load used in this study seemed to be at lower level for significant physiological effects.
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Affiliation(s)
- M Claessens
- Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, Maastricht, The Netherlands.
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Nolles JA, Van Straten EME, Bremer BI, Koopmanschap RE, Verstegen MWA, Schreurs VVAM. Dietary amino acids fed in free form and as protein components do not differently affect postprandial plasma insulin, glucagon, growth hormone and corticosterone responses in rats. J Anim Physiol Anim Nutr (Berl) 2006; 90:289-99. [PMID: 16867074 DOI: 10.1111/j.1439-0396.2005.00598.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This study examined, whether the postprandial fate of dietary amino acids from different amino acid sources is regulated by the responses of insulin, glucagon, corticosterone and growth hormone (GH). Male Wistar rats were cannulated in the vena jugularis and assigned to dietary groups. The diets contained 21% casein or the same amino acids in free form. In the free amino acid diets, methionine level was varied between the groups. The feed was supplied in two distinct meals. In previous experiments it was established that oxidative amino acid losses of the free amino acid diets and protein diets were different. After 3 weeks on those diets, it appeared that the differences in postprandial oxidative losses had been diminished. GH was measured every 12 min, from 144 min before the start of the experimental meal over the following 144 min. Insulin and corticosterone were measured six times from the start of the meal until 270 min after the meal. No differences have been observed between the hormonal responses to both meals at day 5 and at day 26. In conclusion, it has been found that the differences in the oxidative losses between protein and free amino acid meals are not mediated by the combined action of the insulin, glucagon, corticosterone and GH. Postprandial catabolism of amino acids is most probably regulated by substrate induction.
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Affiliation(s)
- J A Nolles
- Human and Animal Physiology Group, Wageningen Institute of Animal Sciences (WIAS) and Research Center, Haarweg 10, NL-6709 PJ Wageningen, The Netherlands.
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Manders RJ, Koopman R, Sluijsmans WE, van den Berg R, Verbeek K, Saris WH, Wagenmakers AJ, van Loon LJ. Co-ingestion of a protein hydrolysate with or without additional leucine effectively reduces postprandial blood glucose excursions in Type 2 diabetic men. J Nutr 2006; 136:1294-9. [PMID: 16614419 DOI: 10.1093/jn/136.5.1294] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This study examined postprandial plasma insulin and glucose responses after co-ingestion of an insulinotropic protein (Pro) hydrolysate with and without additional free leucine with a single bolus of carbohydrate (Cho). Male patients with long-standing Type 2 diabetes (n = 10) and healthy controls (n = 10) participated in 3 trials in which plasma glucose, insulin, and amino acid responses were determined after the ingestion of beverages of different composition (Cho: 0.7 g/kg carbohydrate, Cho+Pro: 0.7 g/kg carbohydrate with 0.3 g/kg protein hydrolysate, or Cho+Pro+Leu: 0.7 g/kg carbohydrate, 0.3 g/kg protein hydrolysate and 0.1 g/kg free leucine). Plasma insulin responses [expressed as area under the curve (AUC)] were 141 and 204% greater in patients with Type 2 diabetes and 66 and 221% greater in the controls in the Cho+Pro and Cho+Pro+Leu trials, respectively, compared with those in the Cho trial (P < 0.05). The concomitant plasma glucose responses were 15 and 12% lower in the patients with Type 2 diabetes and 92 and 97% lower in the control group in the Cho+Pro and Cho+Pro+Leu trials, respectively, compared with those in the Cho trial (P < 0.05). Plasma leucine concentrations correlated with the insulin response in all subjects (r = 0.43, P < 0.001). We conclude that co-ingestion of a protein hydrolysate with or without additional free leucine strongly augments the insulin response after ingestion of a single bolus of carbohydrate, thereby significantly reducing postprandial blood glucose excursions in patients with long-standing Type 2 diabetes.
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Affiliation(s)
- Ralph J Manders
- Department of Human Biology, Maastricht University, the Netherlands.
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Manders RJF, Wagenmakers AJM, Koopman R, Zorenc AHG, Menheere PPCA, Schaper NC, Saris WHM, van Loon LJC. Co-ingestion of a protein hydrolysate and amino acid mixture with carbohydrate improves plasma glucose disposal in patients with type 2 diabetes. Am J Clin Nutr 2005. [DOI: 10.1093/ajcn/82.1.76] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Ralph JF Manders
- From the Departments of Human Biology (RJFM, RK, AHGZ, WHMS, and LJCvL) and Movement Sciences (LJCvL), the Nutrition and Toxicology Research Institute Maastricht (NUTRIM), the Maastricht University, Maastricht, Netherlands; the School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, United Kingdom (AJMW); and the Departments of Clinical Chemistry (PPCAM) and Internal Medicine
| | - Anton JM Wagenmakers
- From the Departments of Human Biology (RJFM, RK, AHGZ, WHMS, and LJCvL) and Movement Sciences (LJCvL), the Nutrition and Toxicology Research Institute Maastricht (NUTRIM), the Maastricht University, Maastricht, Netherlands; the School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, United Kingdom (AJMW); and the Departments of Clinical Chemistry (PPCAM) and Internal Medicine
| | - René Koopman
- From the Departments of Human Biology (RJFM, RK, AHGZ, WHMS, and LJCvL) and Movement Sciences (LJCvL), the Nutrition and Toxicology Research Institute Maastricht (NUTRIM), the Maastricht University, Maastricht, Netherlands; the School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, United Kingdom (AJMW); and the Departments of Clinical Chemistry (PPCAM) and Internal Medicine
| | - Antoine HG Zorenc
- From the Departments of Human Biology (RJFM, RK, AHGZ, WHMS, and LJCvL) and Movement Sciences (LJCvL), the Nutrition and Toxicology Research Institute Maastricht (NUTRIM), the Maastricht University, Maastricht, Netherlands; the School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, United Kingdom (AJMW); and the Departments of Clinical Chemistry (PPCAM) and Internal Medicine
| | - Paul PCA Menheere
- From the Departments of Human Biology (RJFM, RK, AHGZ, WHMS, and LJCvL) and Movement Sciences (LJCvL), the Nutrition and Toxicology Research Institute Maastricht (NUTRIM), the Maastricht University, Maastricht, Netherlands; the School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, United Kingdom (AJMW); and the Departments of Clinical Chemistry (PPCAM) and Internal Medicine
| | - Nicolaas C Schaper
- From the Departments of Human Biology (RJFM, RK, AHGZ, WHMS, and LJCvL) and Movement Sciences (LJCvL), the Nutrition and Toxicology Research Institute Maastricht (NUTRIM), the Maastricht University, Maastricht, Netherlands; the School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, United Kingdom (AJMW); and the Departments of Clinical Chemistry (PPCAM) and Internal Medicine
| | - Wim HM Saris
- From the Departments of Human Biology (RJFM, RK, AHGZ, WHMS, and LJCvL) and Movement Sciences (LJCvL), the Nutrition and Toxicology Research Institute Maastricht (NUTRIM), the Maastricht University, Maastricht, Netherlands; the School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, United Kingdom (AJMW); and the Departments of Clinical Chemistry (PPCAM) and Internal Medicine
| | - Luc JC van Loon
- From the Departments of Human Biology (RJFM, RK, AHGZ, WHMS, and LJCvL) and Movement Sciences (LJCvL), the Nutrition and Toxicology Research Institute Maastricht (NUTRIM), the Maastricht University, Maastricht, Netherlands; the School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, United Kingdom (AJMW); and the Departments of Clinical Chemistry (PPCAM) and Internal Medicine
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Collene AL, Hertzler SR, Williams JA, Wolf BW. Effects of a nutritional supplement containing Salacia oblonga extract and insulinogenic amino acids on postprandial glycemia, insulinemia, and breath hydrogen responses in healthy adults. Nutrition 2005; 21:848-54. [PMID: 15975493 DOI: 10.1016/j.nut.2004.11.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2004] [Accepted: 11/11/2004] [Indexed: 10/25/2022]
Abstract
OBJECTIVE This study evaluated the postprandial glycemic, insulinemic, and breath hydrogen responses to a liquid nutritional product containing Salacia oblonga extract, an herbal alpha-glucosidase inhibitor, and two insulinogenic amino acids. METHODS In a randomized, double-masked, crossover design, 43 healthy subjects were fed the following meals on separate days after overnight fasting: control (C; 480 mL of a study beverage containing 82 g of carbohydrate, 20 g of protein, and 14 g of fat), control plus 3.5 g each of phenylalanine and leucine (AA), control plus 1000 mg of S. oblonga extract (S), and control plus S and AA (SAA). Postprandially, fingerstick capillary plasma glucose and venous serum insulin levels were measured for 180 min, and breath hydrogen excretion was measured for 480 min. RESULTS The baseline-adjusted peak glucose response was not different across meals. However, changes in plasma glucose areas under the curve (0 to 120 min and 0 to 180 min, respectively) compared with C were -9% and -11% for AA (P>0.05 each), -27% and -24% for S (P=0.035 and 0.137), and -27% and -29% for SAA (P<0.05 each). Changes in insulin areas under the curve were +5% and +5% for AA (P>0.05 each), -35% and -36% for S (P<0.001 each), and -6% and -7% for SAA (P>0.05 each). Breath hydrogen excretion was 60% greater (P<0.001) in the S-containing meals than in the C- and AA-containing meals and was associated with mild flatulence. CONCLUSIONS Salacia oblonga extract is a promising nutraceutical ingredient that decreased glycemia in this study. Supplementation with amino acids had no significant additional effect on glycemia.
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Affiliation(s)
- Angela L Collene
- Department of Human Nutrition, College of Human Ecology, The Ohio State University, Columbus, Ohio, USA
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Koopman R, Wagenmakers AJM, Manders RJF, Zorenc AHG, Senden JMG, Gorselink M, Keizer HA, van Loon LJC. Combined ingestion of protein and free leucine with carbohydrate increases postexercise muscle protein synthesis in vivo in male subjects. Am J Physiol Endocrinol Metab 2005; 288:E645-53. [PMID: 15562251 DOI: 10.1152/ajpendo.00413.2004] [Citation(s) in RCA: 175] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The present study was designed to determine postexercise muscle protein synthesis and whole body protein balance following the combined ingestion of carbohydrate with or without protein and/or free leucine. Eight male subjects were randomly assigned to three trials in which they consumed drinks containing either carbohydrate (CHO), carbohydrate and protein (CHO+PRO), or carbohydrate, protein, and free leucine (CHO+PRO+Leu) following 45 min of resistance exercise. A primed, continuous infusion of L-[ring-13C6]phenylalanine was applied, with blood samples and muscle biopsies collected to assess fractional synthetic rate (FSR) in the vastus lateralis muscle as well as whole body protein turnover during 6 h of postexercise recovery. Plasma insulin response was higher in the CHO+PRO+Leu compared with the CHO and CHO+PRO trials (+240 +/- 19% and +77 +/- 11%, respectively, P < 0.05). Whole body protein breakdown rates were lower, and whole body protein synthesis rates were higher, in the CHO+PRO and CHO+PRO+Leu trials compared with the CHO trial (P < 0.05). Addition of leucine in the CHO+PRO+Leu trial resulted in a lower protein oxidation rate compared with the CHO+PRO trial. Protein balance was negative during recovery in the CHO trial but positive in the CHO+PRO and CHO+PRO+Leu trials. In the CHO+PRO+Leu trial, whole body net protein balance was significantly greater compared with values observed in the CHO+PRO and CHO trials (P < 0.05). Mixed muscle FSR, measured over a 6-h period of postexercise recovery, was significantly greater in the CHO+PRO+Leu trial compared with the CHO trial (0.095 +/- 0.006 vs. 0.061 +/- 0.008%/h, respectively, P < 0.05), with intermediate values observed in the CHO+PRO trial (0.0820 +/- 0.0104%/h). We conclude that coingestion of protein and leucine stimulates muscle protein synthesis and optimizes whole body protein balance compared with the intake of carbohydrate only.
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Affiliation(s)
- René Koopman
- Department of Human Biology, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands.
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van Loon LJC, Kruijshoop M, Menheere PPCA, Wagenmakers AJM, Saris WHM, Keizer HA. Amino acid ingestion strongly enhances insulin secretion in patients with long-term type 2 diabetes. Diabetes Care 2003; 26:625-30. [PMID: 12610012 DOI: 10.2337/diacare.26.3.625] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Insulin secretion in response to carbohydrate intake is blunted in type 2 diabetic patients. However, it is not clear whether the insulin response to other stimuli, such as amino acids, is also diminished. Recently, we defined an optimal insulinoptropic mixture containing free leucine, phenylalanine, and a protein hydrolysate that substantially enhances the insulin response in healthy young subjects when coingested with carbohydrate. In this study, we aimed to investigate the insulinotropic capacity of this mixture in long-term type 2 diabetic patients. RESEARCH DESIGN AND METHODS Ten type 2 diabetic patients (aged 59.1 +/- 2.0 years, BMI 26.5 +/- 0.7 kg/m(2)) and 10 healthy control subjects (58.8 +/- 2.1 years, 26.5 +/- 0.7 kg/m(2)) visited our lab twice, during which insulin responses were determined following ingestion of carbohydrate only (CHO) or carbohydrate with the free amino acid/protein mixture (CHO+PRO). All subjects received 0.7 g x kg(-1) x h(-1) carbohydrate with or without 0.35 g x kg(-1) x h(-1) of the amino acid/protein mixture. RESULTS Insulin responses were dramatically increased in the CHO+PRO trial in both the type 2 diabetic and control groups (189 and 114%, respectively) compared with the CHO trial (P < 0.01). Plasma glucose, glucagon, growth hormone, cortisol, IGF-I, and IGF binding protein 3 responses were not different between trials within the 2-h time frame. CONCLUSIONS The insulin secretory capacity in long-term type 2 diabetic patients is substantially underestimated, as the insulin response following carbohydrate intake can be nearly tripled by coingestion of a free amino acid/protein mixture. Future research should be performed to investigate whether such nutritional interventions can improve postprandial glucose disposal.
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Affiliation(s)
- Luc J C van Loon
- Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, Maastricht, the Netherlands.
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30
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Ivy JL. Dietary strategies to promote glycogen synthesis after exercise. CANADIAN JOURNAL OF APPLIED PHYSIOLOGY = REVUE CANADIENNE DE PHYSIOLOGIE APPLIQUEE 2002; 26 Suppl:S236-45. [PMID: 11897899 DOI: 10.1139/h2001-058] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Muscle glycogen is an essential fuel for prolonged intense exercise, and therefore it is important that the glycogen stores be copious for competition and strenuous training regimens. While early research focused on means of increasing the muscle glycogen stores in preparation for competition and its day-to-day replenishment, recent research has focused on the most effective means of promoting its replenishment during the early hours of recovery. It has been observed that muscle glycogen synthesis is twice as rapid if carbohydrate is consumed immediately after exercise as opposed to waiting several hours, and that a rapid rate of synthesis can be maintained if carbohydrate is consumed on a regular basis. For example, supplementing at 30-min intervals at a rate of 1.2 to 1.5 g CHO x kg(-1) body wt x h(-1) appears to maximize synthesis for a period of 4- to 5-h post exercise. If a lighter carbohydrate supplement is desired, however, glycogen synthesis can be enhanced with the addition of protein and certain amino acids. Furthermore, the combination of carbohydrate and protein has the added benefit of stimulating amino acid transport, protein synthesis and muscle tissue repair. Research suggests that aerobic performance following recovery is related to the degree of muscle glycogen replenishment.
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Affiliation(s)
- J L Ivy
- Exercise Physiology and Metabolism Laboratory, Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, USA
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McCarty MF. Hepatic monitoring of essential amino acid availability may regulate IGF-I activity, thermogenesis, and fatty acid oxidation/synthesis. Med Hypotheses 2001; 56:220-4. [PMID: 11425291 DOI: 10.1054/mehy.2000.1154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Diets that are low in certain essential amino acids (EAAs), whether owing to low protein content or poor protein quality, tend to down-regulate systemic IGF-I activity, boost thermogenesis, and suppress hepatic capacity for lipogenesis, while promoting hepatic fatty acid oxidation. It is proposed that for each EAA there is a regulatory protein in hepatocytes whose activity is repressed by adequate levels of its EAA; if one (or more) of these regulatory proteins is active, it serves as a signal of EAA deficiency which then mediates the aforementioned effects on IGF-I activity, thermogenesis, and hepatic fatty acid metabolism. Mechanisms which monitor EAA availability likewise play a role in appetite regulation, thus accounting for the fact that spontaneous calorie consumption tends to be lower on high-protein diets. Diets low in protein quantity or quality may decrease insulin secretion, an effect which should contribute to their impact on IGF-I activity and lipid metabolism. The fact that vegans ingest diets that tend to be relatively low in certain EAAs may play a key role in their characteristic leanness and their decreased risk for diabetes, coronary disease, and cancer.
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Affiliation(s)
- M F McCarty
- Pantox Laboratories, 4622 Santa Fe Street, San Diego, CA 92109, USA
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van Loon LJ, Kruijshoop M, Verhagen H, Saris WH, Wagenmakers AJ. Ingestion of protein hydrolysate and amino acid-carbohydrate mixtures increases postexercise plasma insulin responses in men. J Nutr 2000; 130:2508-13. [PMID: 11015482 DOI: 10.1093/jn/130.10.2508] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
To optimize the postexercise insulin response and to increase plasma amino acid availability, we studied postexercise insulin levels after the ingestion of carbohydrate and wheat protein hydrolysate with and without free leucine and phenylalanine. After an overnight fast, eight male cyclists visited our laboratory on five occasions, during which a control drink and two different beverage compositions in two different doses were tested. After they performed a glycogen-depletion protocol, subjects received a beverage (3.5 mL. kg(-1)) every 30 min to ensure an intake of 1.2 g. kg(-1). h(-1) carbohydrate and 0, 0.2 or 0.4 g. kg(-1). h(-1) protein hydrolysate (and amino acid) mixture. After the insulin response was expressed as the area under the curve, only the ingestion of the beverages containing wheat protein hydrolysate, leucine and phenylalanine resulted in a marked increase in insulin response (+52 and + 107% for the 0.2 and 0.4 g. kg(-1). h(-1) mixtures, respectively; P: < 0. 05) compared with the carbohydrate-only trial). A dose-related effect existed because doubling the dose (0.2-0.4 g. kg(-1). h(-1)) led to an additional rise in insulin response (P: < 0.05). Plasma leucine, phenylalanine and tyrosine concentrations showed strong correlations with the insulin response (P: < 0.0001). This study provides a practical tool to markedly elevate insulin levels and plasma amino acid availability through dietary manipulation, which may be of great value in clinical nutrition, (recovery) sports drinks and metabolic research.
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Affiliation(s)
- L J van Loon
- Nutrition and Toxicology Research Institute NUTRIM, Department of Human Biology, Maastricht University, 6200 MD Maastricht, the Netherlands
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van Loon LJ, Saris WH, Kruijshoop M, Wagenmakers AJ. Maximizing postexercise muscle glycogen synthesis: carbohydrate supplementation and the application of amino acid or protein hydrolysate mixtures. Am J Clin Nutr 2000; 72:106-11. [PMID: 10871568 DOI: 10.1093/ajcn/72.1.106] [Citation(s) in RCA: 227] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Postexercise muscle glycogen synthesis is an important factor in determining the time needed to recover from prolonged exercise. OBJECTIVE This study investigated whether an increase in carbohydrate intake, ingestion of a mixture of protein hydrolysate and amino acids in combination with carbohydrate, or both results in higher postexercise muscle glycogen synthesis rates than does ingestion of 0.8 g*kg(-)(1)*h(-)(1) carbohydrate, provided at 30-min intervals. DESIGN Eight trained cyclists visited the laboratory 3 times, during which a control beverage and 2 other beverages were tested. After the subjects participated in a strict glycogen-depletion protocol, muscle biopsy samples were collected. The subjects received a beverage every 30 min to ensure ingestion of 0.8 g carbohydrate*kg(-)(1)*h(-)(1) (Carb trial), 0.8 g carbohydrate*kg(-)(1)*h(-)(1) plus 0.4 g wheat protein hydrolysate plus free leucine and phenylalanine*kg(-)(1)*h(-)(1) (proven to be highly insulinotropic; Carb + Pro trial), or 1.2 g carbohydrate*kg(-)(1)*h(-)(1) (Carb + Carb trial). After 5 h, a second biopsy was taken. RESULTS Plasma insulin responses in the Carb + Pro and Carb + Carb trials were higher than those in the Carb trial (88 +/- 17% and 46 +/- 18%; P < 0.05). Muscle glycogen synthesis was higher in both trials than in the Carb trial (35. 4 +/- 5.1 and 44.8 +/- 6.8 compared with 16.6 +/- 7.8 micromol glycosol units*g dry wt(-)(1)*h(-)(1), respectively; P < 0.05). CONCLUSIONS Addition of a mixture of protein hydrolysate and amino acids to a carbohydrate-containing solution (at an intake of 0.8 g carbohydrate*kg(-)(1)*h(-)(1)) can stimulate glycogen synthesis. However, glycogen synthesis can also be accelerated by increasing carbohydrate intake (0.4 g*kg(-)(1)*h(-)(1)) when supplements are provided at 30-min intervals.
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Affiliation(s)
- L J van Loon
- From the Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Department of Human Biology, Maastricht University, Maastricht, The Netherlands.
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van Loon LJ, Saris WH, Verhagen H, Wagenmakers AJ. Plasma insulin responses after ingestion of different amino acid or protein mixtures with carbohydrate. Am J Clin Nutr 2000; 72:96-105. [PMID: 10871567 DOI: 10.1093/ajcn/72.1.96] [Citation(s) in RCA: 241] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Protein induces an increase in insulin concentrations when ingested in combination with carbohydrate. Increases in plasma insulin concentrations have been observed after the infusion of free amino acids. However, the insulinotropic properties of different amino acids or protein (hydrolysates) when co-ingested with carbohydrate have not been investigated. OBJECTIVE The aim of this study was to define an amino acid and protein (hydrolysate) mixture with a maximal insulinotropic effect when co-ingested with carbohydrate. DESIGN Eight healthy, nonobese male subjects visited our laboratory, after an overnight fast, on 10 occasions on which different beverage compositions were tested for 2 h. During those trials the subjects ingested 0.8 g*kg(-)(1)*h(-)(1) carbohydrate and 0.4 g*kg(-)(1)*h(-)(1) of an amino acid and protein (hydrolysate) mixture. RESULTS A strong initial increase in plasma glucose and insulin concentrations was observed in all trials, after which large differences in insulin response between drinks became apparent. After we expressed the insulin response as area under the curve during the second hour, ingestion of the drinks containing free leucine, phenylalanine, and arginine and the drinks with free leucine, phenylalanine, and wheat protein hydrolysate were followed by the largest insulin response (101% and 103% greater, respectively, than with the carbohydrate-only drink; P < 0.05). CONCLUSIONS Insulin responses are positively correlated with plasma leucine, phenylalanine, and tyrosine concentrations. A mixture of wheat protein hydrolysate, free leucine, phenylalanine, and carbohydrate can be applied as a nutritional supplement to strongly elevate insulin concentrations.
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Affiliation(s)
- L J van Loon
- Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Department of Human Biology, Maastricht University, Maastricht, The Netherlands.
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Carrithers JA, Williamson DL, Gallagher PM, Godard MP, Schulze KE, Trappe SW. Effects of postexercise carbohydrate-protein feedings on muscle glycogen restoration. J Appl Physiol (1985) 2000; 88:1976-82. [PMID: 10846008 DOI: 10.1152/jappl.2000.88.6.1976] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this investigation was to determine the effects of postexercise eucaloric carbohydrate-protein feedings on muscle glycogen restoration after an exhaustive cycle ergometer exercise bout. Seven male collegiate cyclists [age = 25.6 +/- 1.3 yr, height = 180.9 +/- 3.2 cm, wt = 75.4 +/- 4.0 kg, peak oxygen uptake (VO(2 peak)) = 4.20 +/- 0.2 l/min] performed three trials, each separated by 1 wk: 1) 100% alpha-D-glucose [carbohydrate (CHO)], 2) 70% carbohydrate-20% protein (PRO)-10% fat, and 3) 86% carbohydrate-14% amino acid (AA). All feedings were eucaloric, based on 1.0 g. kg body wt(-1). h(-1) of CHO, and administered every 30 min during a 4-h muscle glycogen restoration period in an 18% wt/vol solution. Muscle biopsies were obtained immediately and 4 h after exercise. Blood samples were drawn immediately after the exercise bout and every 0.5 h for 4 h during the restoration period. Increases in muscle glycogen concentrations for the three feedings (CHO, CHO-PRO, CHO-AA) were 118 mmol/kg dry wt; however, no differences among the feedings were apparent. The serum glucose and insulin responses did not differ throughout the restoration period among the three feedings. These results suggest that muscle glycogen restoration does not appear to be enhanced with the addition of proteins or amino acids to an eucaloric CHO feeding after exhaustive cycle exercise.
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Affiliation(s)
- J A Carrithers
- Human Performance Laboratory, Ball State University, Muncie, Indiana 47306, USA
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Abstract
A reduced propensity to oxidize fat, as indicated by a relatively high fasting respiratory quotient, is a major risk factor for weight gain. Increased insulin secretion works in various ways to impede fat oxidation and promote fat storage. The substantial 'spontaneous' weight loss often seen with very-low-fat dietary regimens may reflect not only a reduced rate of fat ingestion, but also an improved insulin sensitivity of skeletal muscle that down-regulates insulin secretion. Reduction of diurnal insulin secretion may also play a role in the fat loss often achieved with exercise training, low-glycemic-index diets, supplementation with soluble fiber or chromium, low-carbohydrate regimens, and biguanide therapy. The exceptional leanness of vegan cultures may reflect an additional factor - the absence of animal protein. Although dietary protein by itself provokes relatively little insulin release, it can markedly potentiate the insulin response to co-ingested carbohydrate; Western meals typically unite starchy foods with an animal protein-based main course. Thus, postprandial insulin secretion may be reduced by either avoiding animal protein, or segregating it in low-carbohydrate meals; the latter practice is a feature of fad diets stressing 'food combining'. Vegan diets tend to be relatively low in protein, legume protein may be slowly absorbed, and, as compared to animal protein, isolated soy protein provokes a greater release of glucagon, an enhancer of fat oxidation. The low insulin response to rice may mirror its low protein content. Minimizing diurnal insulin secretion in the context of a low fat intake may represent an effective strategy for achieving and maintaining leanness.
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37
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McCARTY MARKF. Dietary Glycemic Index May Influence Cancer Risk by Modulating IGF-I Activity: A Hypothesis. J Med Food 1998. [DOI: 10.1089/jmf.1998.1.123] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Vogel HP, Kroll M, Fritschka E, Quabbe HJ. Twenty-four-hour profiles of growth hormone, prolactin and cortisol in the chronic vegetative state. Clin Endocrinol (Oxf) 1990; 33:631-43. [PMID: 2253414 DOI: 10.1111/j.1365-2265.1990.tb03902.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The 24-h profiles of growth hormone (GH), prolactin (PRL) and cortisol were obtained from 11 patients in the chronic vegetative state in order to gain more insight into the neuroendocrine alterations caused by widespread suprahypothalamic brain damage. Age and sex-matched normal subjects served as a control group. Patients had fewer high-amplitude GH peaks (greater than 20 mU/l: 6 peaks/24 h vs 21 peaks/24-h in controls) and a (non-significant) tendency towards higher basal GH concentrations. PRL concentrations were higher in patients (296 +/- 212 (SD) vs 120 +/- 28 mU/l). Cosinor analysis also showed that 24-h rhythmicity was preserved, but acrophases were more dispersed. A nocturnal PRL acrophase occurred in only three of 11 patients but in 10 of 11 control subjects. The number of PRL peaks was the same in patients and controls. Cortisol concentrations were also higher in patients (298.3 +/- 114.6 vs 193.6 +/- 97.4 nmol/l) with a preserved circadian rhythm. The acrophases, however, were likewise more dispersed. There was no difference in the number of cortisol peaks between patients and controls, but the mean peak duration was shorter in patients (75.4 +/- 28.1 vs 109.5 +/- 28.2 min). The stage of remission was negatively correlated with the 24-h mean and the mean peak amplitude of PRL. No patient showed a normal organization of sleep stages. On visual analysis there was no apparent association between EEG patterns and hormonal parameters. These results suggest that the endocrine hypothalamus is essentially intact in the chronic vegetative state. The observed changes may be due to an altered input from extrahypothalamic brain structures.
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Affiliation(s)
- H P Vogel
- Department of Neurology, Freie Universität Berlin, FR Germany
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Jenkins D, Fletcher SM, Holle A. Apparent suicide by carbon monoxide poisoning in a case of insulinoma. MEDICINE, SCIENCE, AND THE LAW 1982; 22:135-139. [PMID: 6290829 DOI: 10.1177/002580248202200210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A woman, found dead in her garage, had a fatal level of carboxyhaemoglobin in her blood. Her recent medical history tended to support a suspicion of suicide but at autopsy a small islet cell tumour was discovered in her pancreas. Further investigations indicated that she had a high blood insulin level, sufficient to produce lethargy or coma, at the time of death. In the light of these findings it was concluded that her death was accidental. The techniques available for investigating the significance of islet cell tumours found at post-mortem are discussed.
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Bloom SR, Edwards AV, Hardy RN, Malinowska K, Silver M. Cardiovascular and endocrine responses to feeding in the young calf. J Physiol 1975; 253:135-55. [PMID: 1206579 PMCID: PMC1348537 DOI: 10.1113/jphysiol.1975.sp011184] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A number of cardiovascular and endocrine responses which occur during and after feeding in the unweaned calf are described. 2. There was a substantial increase in both heart rate and mean aortic blood pressure during feeding in these animals. This occurred within the first few seconds and persisted throughout the period of ingestion. 3. The concentrations of glucose, insulin and gastrin in arterial plasma rose abruptly during, or immediately after, feeding and elevated values persisted for at least 2 hr. A transient increase in glucagon concentration was also observed. In contrast, feeding appeared to produce no immediate rise in enteroglucagon concentration. 4. The adrenal output of glucocorticoids rose transiently in response to feeding but that of catecholamines was unaffected. 5. Cardiovascular responses to feeding were also examined in other species. In unweaned kids the changes were essentially similar to those observed in the calf but were less pronounced. In lambs a persistent hypertension occurred which was associated with a brief initial tachycardia. In adult dogs ingestion of solid food also caused tachycardia but although the aortic blood pressure rose for a short period at the beginning of feeding, hypotension developed thereafter. 6. The possibility that both the cardiovascular and endocrine responses, which occur during or immediately after feeding, are mediated by the autonomic nervous system is discussed.
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Brown PS, Giuliano R, Hough G. Pituitary regulation of appetite and growth in the turtles Pseudomys scripta elegans and Chelydra serpentina. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1974; 187:205-15. [PMID: 4813415 DOI: 10.1002/jez.1401870203] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Cremer GM, Molnar GD, Taylor WF, Moxness KE, Service FJ, Gatewood LC, Ackerman E, Rosevear JW. Studies of diabetic instability. II. Tests of insulinogenic reserve with infusions of arginine, glucagon, epinephrine, and saline. Metabolism 1971; 20:1083-98. [PMID: 5129010 DOI: 10.1016/0026-0495(71)90033-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Iacono G, Ghionni A, Palomba D, Del Giudice N, Colucci M. [Behavior of somatotropic hormone and plasmatic NEFA during function tests in essential obesity]. ACTA DIABETOLOGICA LATINA 1971; 8:84-98. [PMID: 4937338 DOI: 10.1007/bf01550859] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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