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Chen Y, Wu J. Aging-Related Sarcopenia: Metabolic Characteristics and Therapeutic Strategies. Aging Dis 2024:AD.2024.0407. [PMID: 38739945 DOI: 10.14336/ad.2024.0407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 04/07/2024] [Indexed: 05/16/2024] Open
Abstract
The proportion of the elderly population is gradually increasing as a result of medical care advances, leading to a subsequent surge in geriatric diseases that significantly impact quality of life and pose a substantial healthcare burden. Sarcopenia, characterized by age-related decline in skeletal muscle mass and quality, affects a considerable portion of older adults, particularly the elderly, and can result in adverse outcomes such as frailty, fractures, bedridden, hospitalization, and even mortality. Skeletal muscle aging is accompanied by underlying metabolic changes. Therefore, elucidating these metabolic profiles and specific mechanisms holds promise for informing prevention and treatment strategies for sarcopenia. This review provides a comprehensive overview of the key metabolites identified in current clinical studies on sarcopenia and their potential pathophysiological alterations in metabolic activity. Besides, we examine potential therapeutic strategies for sarcopenia from a perspective focused on metabolic regulation.
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Rajcic D, Kromm F, Hernández-Arriaga A, Brandt A, Baumann A, Staltner R, Camarinha-Silva A, Bergheim I. Supplementing L-Citrulline Can Extend Lifespan in C. elegans and Attenuate the Development of Aging-Related Impairments of Glucose Tolerance and Intestinal Barrier in Mice. Biomolecules 2023; 13:1579. [PMID: 38002262 PMCID: PMC10669166 DOI: 10.3390/biom13111579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/19/2023] [Accepted: 10/24/2023] [Indexed: 11/26/2023] Open
Abstract
L-Citrulline (L-Cit) is discussed to possess a protective effect on intestinal barrier dysfunction but also to diminish aging-associated degenerative processes. Here, the effects of L-Cit on lifespan were assessed in C. elegans, while the effects of L-Cit on aging-associated decline were determined in C57BL/6J mice. For lifespan analysis, C. elegans were treated with ±5 mM L-Cit. Twelve-month-old male C57BL/6J mice (n = 8-10/group) fed a standard chow diet received drinking water ± 2.5 g/kg/d L-Cit or 5 g/kg/d hydrolyzed soy protein (Iso-N-control) for 16 or 32 weeks. Additionally, 4-month-old C57BL/6J mice were treated accordingly for 8 weeks. Markers of senescence, glucose tolerance, intestinal barrier function, and intestinal microbiota composition were analyzed in mice. L-Cit treatment significantly extended the lifespan of C. elegans. The significant increase in markers of senescence and signs of impaired glucose tolerance found in 16- and 20-month-old control mice was attenuated in L-Cit-fed mice, which was associated with protection from intestinal barrier dysfunction and a decrease in NO2- levels in the small intestine, while no marked differences in intestinal microbiota composition were found when comparing age-matched groups. Our results suggest that pharmacological doses of L-Cit may have beneficial effects on lifespan in C. elegans and aging-associated decline in mice.
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Affiliation(s)
- Dragana Rajcic
- Department of Nutritional Sciences, Molecular Nutritional Science, University of Vienna, 1090 Vienna, Austria
| | - Franziska Kromm
- Department of Nutritional Sciences, Molecular Nutritional Science, University of Vienna, 1090 Vienna, Austria
| | | | - Annette Brandt
- Department of Nutritional Sciences, Molecular Nutritional Science, University of Vienna, 1090 Vienna, Austria
| | - Anja Baumann
- Department of Nutritional Sciences, Molecular Nutritional Science, University of Vienna, 1090 Vienna, Austria
| | - Raphaela Staltner
- Department of Nutritional Sciences, Molecular Nutritional Science, University of Vienna, 1090 Vienna, Austria
| | - Amélia Camarinha-Silva
- Institute of Animal Science, University of Hohenheim, 70593 Stuttgart, Germany (A.C.-S.)
| | - Ina Bergheim
- Department of Nutritional Sciences, Molecular Nutritional Science, University of Vienna, 1090 Vienna, Austria
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Wilkinson K, Koscien CP, Monteyne AJ, Wall BT, Stephens FB. Association of postprandial postexercise muscle protein synthesis rates with dietary leucine: A systematic review. Physiol Rep 2023; 11:e15775. [PMID: 37537134 PMCID: PMC10400406 DOI: 10.14814/phy2.15775] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/20/2023] [Accepted: 07/05/2023] [Indexed: 08/05/2023] Open
Abstract
BACKGROUND Dietary protein ingestion augments post (resistance) exercise muscle protein synthesis (MPS) rates. It is thought that the dose of leucine ingested within the protein (leucine threshold hypothesis) and the subsequent plasma leucine variables (leucine trigger hypothesis; peak magnitude, rate of rise, and total availability) determine the magnitude of the postprandial postexercise MPS response. METHODS A quantitative systematic review was performed extracting data from studies that recruited healthy adults, applied a bout of resistance exercise, ingested a bolus of protein within an hour of exercise, and measured plasma leucine concentrations and MPS rates (delta change from basal). RESULTS Ingested leucine dose was associated with the magnitude of the MPS response in older, but not younger, adults over acute (0-2 h, r2 = 0.64, p = 0.02) and the entire postprandial (>2 h, r2 = 0.18, p = 0.01) period. However, no single plasma leucine variable possessed substantial predictive capacity over the magnitude of MPS rates in younger or older adults. CONCLUSION Our data provide support that leucine dose provides predictive capacity over postprandial postexercise MPS responses in older adults. However, no threshold in older adults and no plasma leucine variable was correlated with the magnitude of the postexercise anabolic response.
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Affiliation(s)
- Kiera Wilkinson
- Nutritional Physiology Research Group, Public Health and Sport Sciences, Faculty of Health and Life SciencesUniversity of ExeterExeterUK
| | - Christopher P. Koscien
- Nutritional Physiology Research Group, Public Health and Sport Sciences, Faculty of Health and Life SciencesUniversity of ExeterExeterUK
| | - Alistair J. Monteyne
- Nutritional Physiology Research Group, Public Health and Sport Sciences, Faculty of Health and Life SciencesUniversity of ExeterExeterUK
| | - Benjamin T. Wall
- Nutritional Physiology Research Group, Public Health and Sport Sciences, Faculty of Health and Life SciencesUniversity of ExeterExeterUK
| | - Francis B. Stephens
- Nutritional Physiology Research Group, Public Health and Sport Sciences, Faculty of Health and Life SciencesUniversity of ExeterExeterUK
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Park HY, Kim SW, Seo J, Jung YP, Kim H, Kim AJ, Kim S, Lim K. Dietary Arginine and Citrulline Supplements for Cardiovascular Health and Athletic Performance: A Narrative Review. Nutrients 2023; 15:1268. [PMID: 36904267 PMCID: PMC10005484 DOI: 10.3390/nu15051268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023] Open
Abstract
The global market for nutritional supplements (NS) is growing rapidly, and the use of L-arginine (Arg), L-citrulline (Cit), and citrulline malate (CitMal) supplements has been shown to enhance cardiovascular health and athletic performance. Over the past decade, Arg, Cit, and CitMal supplements have received considerable attention from researchers in the field of exercise nutrition, who have investigated their potential effects on hemodynamic function, endothelial function, aerobic and anaerobic capacity, strength, power, and endurance. Previous studies were reviewed to determine the potential impact of Arg, Cit, and CitMal supplements on cardiovascular health and exercise performance. By synthesizing the existing literature, the study aimed to provide insight into the possible uses and limitations of these supplements for these purposes. The results showed that both recreational and trained athletes did not see improved physical performance or increased nitric oxide (NO) synthesis with 0.075 g or 6 g doses of Arg supplement per body weight. However, 2.4 to 6 g of Cit per day for 7 to 16 days of various NSs had a positive impact, increasing NO synthesis, enhancing athletic performance indicators, and reducing feelings of exertion. The effects of an 8 g acute dose of CitMal supplement were inconsistent, and more research is needed to determine its impact on muscle endurance performance. Based on the positive effects reported in previous studies, further testing is warranted in various populations that may benefit from nutritional supplements, including aerobic and anaerobic athletes, resistance-trained individuals, elderly people, and clinical populations, to determine the impact of different doses, timing of ingestion, and long-term and acute effects of Arg, Cit, and CitMal supplements on cardiovascular health and athletic performance.
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Affiliation(s)
- Hun-Young Park
- Physical Activity and Performance Institute, Konkuk University, Seoul 05029, Republic of Korea
- Department of Sports Medicine and Science, Graduate School, Konkuk University, Seoul 05029, Republic of Korea
| | - Sung-Woo Kim
- Physical Activity and Performance Institute, Konkuk University, Seoul 05029, Republic of Korea
- Department of Sports Medicine and Science, Graduate School, Konkuk University, Seoul 05029, Republic of Korea
| | - Jisoo Seo
- Department of Sports Medicine and Science, Graduate School, Konkuk University, Seoul 05029, Republic of Korea
| | - Yanghoon P. Jung
- CJ CheilJedang Food & Nutrition Tech, Jung-gu, Seoul 04527, Republic of Korea
| | - Hyunji Kim
- CJ CheilJedang Food & Nutrition Tech, Jung-gu, Seoul 04527, Republic of Korea
| | - Ah-Jin Kim
- CJ CheilJedang Food & Nutrition Tech, Jung-gu, Seoul 04527, Republic of Korea
| | - Sonwoo Kim
- CJ CheilJedang Food & Nutrition Tech, Jung-gu, Seoul 04527, Republic of Korea
| | - Kiwon Lim
- Physical Activity and Performance Institute, Konkuk University, Seoul 05029, Republic of Korea
- Department of Sports Medicine and Science, Graduate School, Konkuk University, Seoul 05029, Republic of Korea
- Department of Physical Education, Konkuk University, Seoul 05029, Republic of Korea
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Effects of L-Citrulline Supplementation on Endothelial Function and Blood Pressure in Hypertensive Postmenopausal Women. Nutrients 2022; 14:nu14204396. [PMID: 36297080 PMCID: PMC9609406 DOI: 10.3390/nu14204396] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/15/2022] [Accepted: 10/18/2022] [Indexed: 11/17/2022] Open
Abstract
Aging and menopause are associated with decreased nitric oxide bioavailability due to reduced L-arginine (L-ARG) levels contributing to endothelial dysfunction (ED). ED precedes arterial stiffness and hypertension development, a major risk factor for cardiovascular disease. This study investigated the effects of L-citrulline (L-CIT) on endothelial function, aortic stiffness, and resting brachial and aortic blood pressures (BP) in hypertensive postmenopausal women. Twenty-five postmenopausal women were randomized to 4 weeks of L-CIT (10 g) or placebo (PL). Serum L-ARG, brachial artery flow-mediated dilation (FMD), aortic stiffness (carotid-femoral pulse wave velocity, cfPWV), and resting brachial and aortic BP were assessed at 0 and 4 weeks. L-CIT supplementation increased L-ARG levels (Δ13 ± 2 vs. Δ−2 ± 2 µmol/L, p < 0.01) and FMD (Δ1.4 ± 2.0% vs. Δ−0.5 ± 1.7%, p = 0.03) compared to PL. Resting aortic diastolic BP (Δ−2 ± 4 vs. Δ2 ± 5 mmHg, p = 0.01) and mean arterial pressure (Δ−2 ± 4 vs. Δ2 ± 6 mmHg, p = 0.04) were significantly decreased after 4 weeks of L-CIT compared to PL. Although not statistically significant (p = 0.07), cfPWV decreased after L-CIT supplementation by ~0.66 m/s. These findings suggest that L-CIT supplementation improves endothelial function and aortic BP via increased L-ARG availability.
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Yu T, Park YM, Wang L, Deuster PA. L-citrulline prevents heat-induced mitochondrial dysfunction and cell injury through nitric oxide-mediated Drp1 inhibition in mouse C2C12 myoblasts. Br J Nutr 2022; 129:1-24. [PMID: 35791786 DOI: 10.1017/s0007114522001982] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Severe heat exposure causes mitochondrial fragmentation and dysfunction, which contribute to the pathogenesis of heat-related illness. L-citrulline is a naturally occurring amino acid and has been suggested to influence heat shock responses. This study aimed to test whether L-citrulline supplementation would preserve mitochondrial integrity and attenuate heat-induced skeletal muscle injury, and elucidate the underlying mechanisms. At 37°C, L-citrulline (2 mM) increased mitochondrial elongation in mouse C2C12 myoblasts, a process associated with a reduction in mitochondrial fission protein Drp1 levels. Mechanistic studies revealed that L-citrulline increased cellular nitric oxide (NO) levels, but not S-nitrosylation of Drp1. L-citrulline caused a decrease in phosphorylation of Drp1 at Ser 616 and an increase in phosphorylation of Drp1 at Ser 637, which resulted in a reduced mitochondrial localization of Drp1. L-NAME, a non-selective NO synthase inhibitor, abolished the increase in L-citrulline-induced NO levels and inhibited Drp1 phosphorylation changes and mitochondrial elongation, which indicates involvement of a NO-dependent pathway. Under 43°C heat stress conditions, L-citrulline prevented translocation of Drp1 to mitochondria, mitochondrial fragmentation and decreased membrane potential. Finally, L-citrulline pretreatment inhibited heat-induced reactive oxygen species (ROS) overproduction, caspase 3/7 activation, apoptotic cell death, and improved cell viability. NO inhibitor L-NAME abolished all the above protective effects of L-citrulline under heat stress. Our results suggest that L-citrulline prevents heat-induced mitochondrial dysfunction and cell injury through NO-mediated Drp1 inhibition in C2C12 myoblasts. L-citrulline may be an effective treatment for heat-related illnesses and other mitochondrial diseases.
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Affiliation(s)
- Tianzheng Yu
- Consortium for Health and Military Performance, Department of Military and Emergency Medicine, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Yu Min Park
- Consortium for Health and Military Performance, Department of Military and Emergency Medicine, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Li Wang
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
- Department of Pathology, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Patricia A Deuster
- Consortium for Health and Military Performance, Department of Military and Emergency Medicine, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD, USA
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Kim M, Isoda H, Okura T. Effect of Citrulline and Leucine Intake with Exercises on Body Composition, Physical Activity, and Amino Acid Concentration in Older Women: A Randomized Double-Blind Placebo-Controlled Study. Foods 2021; 10:foods10123117. [PMID: 34945668 PMCID: PMC8701161 DOI: 10.3390/foods10123117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/30/2021] [Accepted: 12/09/2021] [Indexed: 01/12/2023] Open
Abstract
The combined intake of citrulline (CIT) and leucine (LEU) can stimulate protein synthesis. Therefore, this study aimed to investigate the effect of combined intake of CIT and LEU accompanied by exercise for 20 weeks on body composition, physical activity (PA), and amino acid concentrations in older Japanese women with low body mass index (BMI) (16 to 21 kg/m2) using a randomized, double-blind, placebo-controlled design. The supplement was administered twice a day for 20 weeks (Ex (exercise) + CIT·LEU group, n = 10: mainly 0.8 g CIT and 1.6 g LEU; Ex + Placebo group, n = 13: mainly 3.5 g carbohydrate). Additionally, both groups exercised (weight-bearing exercise, square stepping exercise) once a week for 75 min. Body composition, PA, and amino acid concentrations in the plasma were measured. Body weight, BMI, body mass, household PA, total PA, and phenylalanine significantly increased in the Ex + CIT·LEU group (p < 0.05) post intervention. This study suggests that the combined intake of CIT and LEU accompanied by exercise can improve body weight, BMI, body mass, and PA in older women with low BMI, which may prevent sarcopenia and frailty.
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Affiliation(s)
- Mijin Kim
- R&D Center for Tailor-Made QOL, University of Tsukuba, Tsukuba 305-8550, Japan; (H.I.); (T.O.)
- Correspondence: ; Tel.: +81-29-859-1834
| | - Hiroko Isoda
- R&D Center for Tailor-Made QOL, University of Tsukuba, Tsukuba 305-8550, Japan; (H.I.); (T.O.)
- Alliance for Research on the Mediterranean and North Africa, University of Tsukuba, Tsukuba 305-8572, Japan
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan
| | - Tomohiro Okura
- R&D Center for Tailor-Made QOL, University of Tsukuba, Tsukuba 305-8550, Japan; (H.I.); (T.O.)
- Faculty of Health and Sport Science, University of Tsukuba, Tsukuba 305-8572, Japan
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Smeets ETHC, Mensink RP, Joris PJ. Effects of L-citrulline supplementation and watermelon consumption on longer-term and postprandial vascular function and cardiometabolic risk markers: A meta-analysis of randomized controlled trials in adults. Br J Nutr 2021; 128:1-34. [PMID: 34863321 PMCID: PMC9592950 DOI: 10.1017/s0007114521004803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 11/15/2021] [Accepted: 11/30/2021] [Indexed: 11/16/2022]
Abstract
L-citrulline may improve non-invasive vascular function and cardiometabolic risk markers through increases in L-arginine bioavailability and nitric oxide synthesis. A meta-analysis of randomized controlled trials (RCTs) was performed to examine longer-term and postprandial effects of L-citrulline supplementation and watermelon consumption on these markers for cardiovascular disease in adults. Summary estimates of weighted mean differences (WMDs) in vascular function and cardiometabolic risk markers with accompanying 95% confidence intervals (CIs) were calculated using random or fixed-effect meta-analyses. Seventeen RCTs were included involving an L-citrulline intervention, of which six studied postprandial and twelve longer-term effects. Five studies investigated longer-term effects of watermelon consumption and five assessed effects during the postprandial phase. Longer-term L-citrulline supplementation improved brachial artery flow-mediated vasodilation (FMD) by 0.9 %-point (95 % CI: 0.7 to 1.1, P < 0.001). Longer-term watermelon consumption improved pulse wave velocity by 0.9 m/s (95% CI: 0.1 to 1.5, P < 0.001), while effects on FMD were not studied. No postprandial effects on vascular function markers were found. Postprandial glucose concentrations decreased by 0.6 mmol/L (95% CI: 0.4 to 0.7, P < 0.001) following watermelon consumption, but no other longer-term or postprandial effects were observed on cardiometabolic risk markers. To conclude, longer-term L-citrulline supplementation and watermelon consumption may improve vascular function, suggesting a potential mechanism by which increased L-citrulline intake beneficially affects cardiovascular health outcomes in adults. No effects on postprandial vascular function markers were found, while more research is needed to investigate effects of L-citrulline and watermelon on risk markers related to cardiometabolic health.
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Affiliation(s)
- Ellen T. H. C. Smeets
- Department of Nutrition and Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, 6200 MD, Maastricht, The Netherlands
| | - Ronald P. Mensink
- Department of Nutrition and Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, 6200 MD, Maastricht, The Netherlands
| | - Peter J. Joris
- Department of Nutrition and Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, 6200 MD, Maastricht, The Netherlands
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Theodorou AA, Zinelis PT, Malliou VJ, Chatzinikolaou PN, Margaritelis NV, Mandalidis D, Geladas ND, Paschalis V. Acute L-Citrulline Supplementation Increases Nitric Oxide Bioavailability but Not Inspiratory Muscle Oxygenation and Respiratory Performance. Nutrients 2021; 13:nu13103311. [PMID: 34684312 PMCID: PMC8537281 DOI: 10.3390/nu13103311] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/17/2021] [Accepted: 09/20/2021] [Indexed: 11/16/2022] Open
Abstract
The present study aimed to investigate whether acute L-citrulline supplementation would affect inspiratory muscle oxygenation and respiratory performance. Twelve healthy males received 6 g of L-citrulline or placebo in a double-blind crossover design. Pulmonary function (i.e., forced expired volume in 1 s, forced vital capacity and their ratio), maximal inspiratory pressure (MIP), fractional exhaled nitric oxide (NO•), and sternocleidomastoid muscle oxygenation were measured at baseline, one hour post supplementation, and after an incremental resistive breathing protocol to task failure of the respiratory muscles. The resistive breathing task consisted of 30 inspirations at 70% and 80% of MIP followed by continuous inspirations at 90% of MIP until task failure. Sternocleidomastoid muscle oxygenation was assessed using near-infrared spectroscopy. One-hour post-L-citrulline supplementation, exhaled NO• was significantly increased (19.2%; p < 0.05), and this increase was preserved until the end of the resistive breathing (16.4%; p < 0.05). In contrast, no difference was observed in the placebo condition. Pulmonary function and MIP were not affected by the L-citrulline supplementation. During resistive breathing, sternocleidomastoid muscle oxygenation was significantly reduced, with no difference noted between the two supplementation conditions. In conclusion, a single ingestion of 6 g L-citrulline increased NO• bioavailability but not the respiratory performance and inspiratory muscle oxygenation.
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Affiliation(s)
- Anastasios A. Theodorou
- Department of Life Sciences, School of Sciences, European University Cyprus, Nicosia 1516, Cyprus
- Correspondence:
| | - Panagiotis T. Zinelis
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, 17237 Athens, Greece; (P.T.Z.); (V.J.M.); (D.M.); (N.D.G.); (V.P.)
| | - Vassiliki J. Malliou
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, 17237 Athens, Greece; (P.T.Z.); (V.J.M.); (D.M.); (N.D.G.); (V.P.)
| | - Panagiotis N. Chatzinikolaou
- Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, 61122 Serres, Greece; (P.N.C.); (N.V.M.)
| | - Nikos V. Margaritelis
- Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, 61122 Serres, Greece; (P.N.C.); (N.V.M.)
- Dialysis Unit, 424 General Military Hospital of Thessaloniki, 56429 Thessaloniki, Greece
| | - Dimitris Mandalidis
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, 17237 Athens, Greece; (P.T.Z.); (V.J.M.); (D.M.); (N.D.G.); (V.P.)
| | - Nickos D. Geladas
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, 17237 Athens, Greece; (P.T.Z.); (V.J.M.); (D.M.); (N.D.G.); (V.P.)
| | - Vassilis Paschalis
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, 17237 Athens, Greece; (P.T.Z.); (V.J.M.); (D.M.); (N.D.G.); (V.P.)
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10
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Vincellette CM, Losso J, Early K, Spielmann G, Irving BA, Allerton TD. Supplemental Watermelon Juice Attenuates Acute Hyperglycemia-Induced Macro-and Microvascular Dysfunction in Healthy Adults. J Nutr 2021; 151:3450-3458. [PMID: 34510203 PMCID: PMC8562079 DOI: 10.1093/jn/nxab279] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 05/06/2021] [Accepted: 07/30/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Acute hyperglycemia reduces NO bioavailability and causes macro- and microvascular dysfunction. Watermelon juice (WMJ) is a natural source of the amino acid citrulline, which is metabolized to form arginine for the NO cycle and may improve vascular function. OBJECTIVES We examined the effects of 2 weeks of WMJ compared to a calorie-matched placebo (PLA) to attenuate acute hyperglycemia-induced vascular dysfunction. METHODS In a randomized, placebo-controlled, double-blind, crossover trial, 6 men and 11 women (aged 21-25; BMI, 23.5 ± 3.2 kg/m2) received 2 weeks of daily WMJ (500 mL) or a PLA drink followed by an oral-glucose-tolerance test. Postprandial flow-mediated dilation (FMD) was measured by ultrasound (primary outcome), while postprandial microvascular blood flow (MVBF) and ischemic reperfusion were measured by near-infrared spectroscopy (NIRS) vascular occlusion test (VOT). RESULTS The postprandial FMD area AUC was higher after WMJ supplementation compared to PLA supplementation (838 ± 459% · 90 min compared with 539 ± 278% · 90 min; P = 0.03). The postprandial MVBF (AUC) was higher (P = 0.01) following WMJ supplementation (51.0 ± 29.1 mL blood · 100 mL tissue-1 · min-1 · 90 min) compared to the PLA (36.0 ± 20.5 mL blood · 100 mL tissue-1 · min-1 · 90 min; P = 0.01). There was a significant treatment effect (P = 0.048) for WMJ supplementation (71.2 ± 1.5%) to increase baseline tissue oxygen saturation (StO2%) when compared to PLA (65.9 ± 1.7%). The ischemic-reperfusion slope was not affected by WMJ treatment (P = 0.83). CONCLUSIONS Two weeks of daily WMJ supplementation improved FMD and some aspects of microvascular function (NIRS-VOT) during experimentally induced acute hyperglycemia in healthy adults. Preserved postprandial endothelial function and enhanced skeletal muscle StO2% are likely partially mediated by increased NO production (via citrulline conversion into arginine) and by the potential antioxidant effect of other bioactive compounds in WMJ.
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Affiliation(s)
| | - Jack Losso
- Louisiana State University, School of Nutrition and Food Sciences, Baton Rouge, LA, USA
| | - Kate Early
- Columbus State University, Department of Kinesiology and Health Sciences, Columbus, GA, USA
| | - Guillaume Spielmann
- Louisiana State University, Department of Kinesiology, Baton Rouge, LA, USA,Pennington Biomedical Research Center, Vascular Metabolism Laboratory, Baton Rouge, LA, USA
| | - Brian A Irving
- Louisiana State University, Department of Kinesiology, Baton Rouge, LA, USA,Pennington Biomedical Research Center, Vascular Metabolism Laboratory, Baton Rouge, LA, USA
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Gough LA, Sparks SA, McNaughton LR, Higgins MF, Newbury JW, Trexler E, Faghy MA, Bridge CA. A critical review of citrulline malate supplementation and exercise performance. Eur J Appl Physiol 2021; 121:3283-3295. [PMID: 34417881 PMCID: PMC8571142 DOI: 10.1007/s00421-021-04774-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 07/20/2021] [Indexed: 01/03/2023]
Abstract
As a nitric oxide (NO) enhancer, citrulline malate (CM) has recently been touted as a potential ergogenic aid to both resistance and high-intensity exercise performance, as well as the recovery of muscular performance. The mechanism has been associated with enhanced blood flow to active musculature, however, it might be more far-reaching as either ammonia homeostasis could be improved, or ATP production could be increased via greater availability of malate. Moreover, CM might improve muscle recovery via increased nutrient delivery and/or removal of waste products. To date, a single acute 8 g dose of CM on either resistance exercise performance or cycling has been the most common approach, which has produced equivocal results. This makes the effectiveness of CM to improve exercise performance difficult to determine. Reasons for the disparity in conclusions seem to be due to methodological discrepancies such as the testing protocols and the associated test–retest reliability, dosing strategy (i.e., amount and timing), and the recent discovery of quality control issues with some manufacturers stated (i.e., citrulline:malate ratios). Further exploration of the optimal dose is therefore required including quantification of the bioavailability of NO, citrulline, and malate following ingestion of a range of CM doses. Similarly, further well-controlled studies using highly repeatable exercise protocols with a large aerobic component are required to assess the mechanisms associated with this supplement appropriately. Until such studies are completed, the efficacy of CM supplementation to improve exercise performance remains ambiguous.
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Affiliation(s)
- Lewis A Gough
- Research Centre for Life and Sport Science (CLaSS), Human Performance and Health Research Group, Birmingham City University, Birmingham, UK.
| | - S Andy Sparks
- Sports Nutrition and Performance Research Group, Department of Sport and Physical Activity, Edge Hill University, Ormskirk, UK
| | - Lars R McNaughton
- Sports Nutrition and Performance Research Group, Department of Sport and Physical Activity, Edge Hill University, Ormskirk, UK
| | | | - Josh W Newbury
- Research Centre for Life and Sport Science (CLaSS), Human Performance and Health Research Group, Birmingham City University, Birmingham, UK
| | | | - Mark A Faghy
- Human Sciences Research Centre, University of Derby, Derby, UK
| | - Craig A Bridge
- Sports Nutrition and Performance Research Group, Department of Sport and Physical Activity, Edge Hill University, Ormskirk, UK
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12
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Understanding the effects of nutrition and post-exercise nutrition on skeletal muscle protein turnover: Insights from stable isotope studies. CLINICAL NUTRITION OPEN SCIENCE 2021. [DOI: 10.1016/j.nutos.2021.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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13
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Jegatheesan P, Vicente C, Marquet de Rouge P, Neveux N, Ramassamy R, Magassa S, Aussel C, Raynaud-Simon A, Cynober L, De Bandt JP. Combined effect of citrulline and lactoserum on amino acid availability in aged rats. Nutrition 2021; 87-88:111196. [PMID: 33744643 DOI: 10.1016/j.nut.2021.111196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/28/2021] [Accepted: 01/30/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Age-associated sarcopenia is due to anabolic resistance to feeding. Muscle protein synthesis is improved by fast proteins (e.g., lactoserum), which increase peripheral amino acid (AA) bioavailability more rapidly than slow proteins (e.g., casein), and by citrulline. Citrulline, which limits splanchnic sequestration of AA, may more effectively increase peripheral AA bioavailability when combined with lactoserum than with casein when administered as an oral nutritional protein supplement. METHODS In this study, 25 fasted aged rats received a single gavage administration of lactoserum or casein 0.4 g/kg, alone or with citrulline 0.4 g/kg, and AA pharmacokinetics, glucose, insulin, triglycerides, and insulin-like growth factor 1 (IGF1) were monitored for 4 h. At 4 h, muscle protein and AA contents and protein synthesis activation were measured. RESULTS While lactoserum was associated with higher AA availability, citrulline exerts only limited effects on the plasma profile of AAs from the two proteins. Maximum plasma citrulline was reached earlier with casein (T90 min) than with lactoserum (T120 min). A protein x citrulline interaction was observed for some plasma and muscle AA levels with a significant activation of mechanistic target of rapamycin complex 1 (mTORC1) signaling suggesting higher anabolism with the combination of citrulline and lactoserum. Lower plasma and muscle AA levels with citrulline and lactoserum compared to lactoserum alone suggest a greater AA utilization in a context of muscle anabolic signaling activation. CONCLUSION Provision of a citrulline-lactoserum combination as a nutritional supplement could therefore be beneficial in terms of muscle protein balance and prevention of sarcopenia. Further studies are warranted to evaluate the efficacy of this combination.
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Affiliation(s)
| | | | | | - Nathalie Neveux
- Faculty of Pharmacy, Paris University, Paris, France; Clinical Chemistry Department, Hôpital Cochin, Asssistance Publique - Hôpitaux de Paris, Paris, France
| | | | | | | | - Agathe Raynaud-Simon
- Faculty of Pharmacy, Paris University, Paris, France; Gerontology Department, Hôpital Bichat, Asssistance Publique - Hôpitaux de Paris, HU Paris-Nord-Val-de-Seine, Paris, France
| | - Luc Cynober
- Faculty of Pharmacy, Paris University, Paris, France; Clinical Chemistry Department, Hôpital Cochin, Asssistance Publique - Hôpitaux de Paris, Paris, France
| | - Jean-Pascal De Bandt
- Faculty of Pharmacy, Paris University, Paris, France; Clinical Chemistry Department, Hôpital Cochin, Asssistance Publique - Hôpitaux de Paris, Paris, France.
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14
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Hughes WE, Zinkevich N, Gutterman DD, Beyer AM. Hypertension preserves the magnitude of microvascular flow-mediated dilation following transient elevation in intraluminal pressure. Physiol Rep 2021; 9:e14507. [PMID: 33587335 PMCID: PMC7883808 DOI: 10.14814/phy2.14507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVE The objective of this study was to measure flow-mediated dilation (FMD) prior to and following transient increases in intraluminal pressure (IILP) in resistance arterioles isolated from subjects with and without coronary artery disease (CAD) (CAD and non-CAD) and non-CAD subjects with hypertension. METHODS Arterioles were isolated from discarded surgical tissues (adipose and atrial) from patients without coronary artery disease (non-CAD; ≤1 risk factor, excluding hypertension), with CAD, and non-CAD patients with hypertension (hypertension as the only risk factor). To simulate transient hypertension, increased IILP was generated (150 mmHg, 30 min) by gravity. Arterioles were constricted with endothelin-1, followed by FMD and endothelial-independent dilation prior to and following exposure to IILP. RESULTS IILP reduced FMD in non-CAD and CAD arterioles relative to pre-IILP (p <.05 at 100 cmH2 O). In contrast, arterioles from non-CAD hypertensive subjects exhibited no reduction in maximal FMD following IILP (p = .84 at 100 cmH2 O). FMD was reduced by L-NAME prior to IILP in non-CAD hypertensive patients (p < .05 at 100 cmH2 O); however, following IILP, FMD was inhibited by peg-cat (p < .05 at 100 cmH2 O), indicating a switch from NO to H2 O2 as the mechanism of dilation. CONCLUSIONS Acute exposure (30 min) to IILP (150 mmHg) attenuates the magnitude of FMD in non-CAD and CAD resistance arterioles. The presence of clinically diagnosed hypertension in non-CAD resistance arterioles preserves the magnitude of FMD following IILP as a result of a compensatory switch from NO to H2 O2 as the mechanism of dilation.
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Affiliation(s)
- William E. Hughes
- Department of MedicineMedical College of WisconsinMilwaukeeWIUSA
- Cardiovascular CenterMedical College of WisconsinMilwaukeeWIUSA
| | - Natalya Zinkevich
- Cardiovascular CenterMedical College of WisconsinMilwaukeeWIUSA
- Department of Health and MedicineCarroll UniversityWaukeshaWIUSA
| | - David D. Gutterman
- Department of MedicineMedical College of WisconsinMilwaukeeWIUSA
- Cardiovascular CenterMedical College of WisconsinMilwaukeeWIUSA
- Department of PhysiologyMedical College of WisconsinMilwaukeeWIUSA
| | - Andreas M. Beyer
- Department of MedicineMedical College of WisconsinMilwaukeeWIUSA
- Cardiovascular CenterMedical College of WisconsinMilwaukeeWIUSA
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15
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Cherubini JM, Cheng JL, Williams JS, MacDonald MJ. Sleep deprivation and endothelial function: reconciling seminal evidence with recent perspectives. Am J Physiol Heart Circ Physiol 2020; 320:H29-H35. [PMID: 33064569 DOI: 10.1152/ajpheart.00607.2020] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Sleep is critical for the maintenance of physiological homeostasis and, as such, inadequate sleep beckons a myriad of pathologies. Sleep deprivation is a growing health concern in contemporary society since short sleep durations are associated with increased cardiovascular disease risk and atherosclerotic plaque development. Vascular endothelial dysfunction is an antecedent to atherosclerosis and cardiovascular disease. Herein, we review seminal literature indicating that short sleep durations attenuate endothelial function and explore more recent evidence indicating that sleep deprivation perturbs autonomic balance and the circadian rhythmicity of peripheral vascular clock components. We further examine literature that indicates a mechanistic link between short sleep duration and endothelial dysfunction and subsequent morbidity. Understanding the mechanisms that regulate endothelial function in the context of sleep deprivation facilitates the development and optimization of interventions, such as exercise, that mitigate the ramifications of inadequate sleep on vascular function and cardiovascular health.Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/sleep-deprivation-and-endothelial-function/.
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Affiliation(s)
| | - Jem L Cheng
- Vascular Dynamics Lab, McMaster University, Hamilton, Ontario, Canada
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16
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The Potential Role of Fish-Derived Protein Hydrolysates on Metabolic Health, Skeletal Muscle Mass and Function in Ageing. Nutrients 2020; 12:nu12082434. [PMID: 32823615 PMCID: PMC7468851 DOI: 10.3390/nu12082434] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/11/2020] [Accepted: 08/11/2020] [Indexed: 02/07/2023] Open
Abstract
Fish protein represents one of the most widely consumed dietary protein sources by humans. The processing of material from the fishing industry generates substantial unexploited waste products, many of which possess high biological value. Protein hydrolysates, such as fish protein hydrolysates (FPH), containing predominantly di- and tripeptides, are more readily absorbed than free amino acids and intact protein. Furthermore, in animal models, FPH have been shown to possess numerous beneficial properties for cardiovascular, neurological, intestinal, renal, and immune health. Ageing is associated with the loss of skeletal muscle mass and function, as well as increased oxidative stress, compromised vascularisation, neurological derangements, and immunosenescence. Thus, there appears to be a potential application for FPH in older persons as a high-quality protein source that may also confer additional health benefits. Despite this, there remains a dearth of information concerning the impact of FPH on health outcomes in humans. The limited evidence from human interventional trials suggests that FPH may hold promise for supporting optimal body composition and maintaining gut integrity. FPH also provide a high-quality source of dietary protein without negatively impacting on subjective appetite perceptions or regulatory hormones. Further studies are needed to assess the impact and utility of FPH on skeletal muscle health in older persons, ideally comparing FPH to ‘established’ protein sources or a non-bioactive, nitrogen-matched control. In particular, the effects of acute and chronic FPH consumption on post-exercise aminoacidaemia, skeletal muscle protein synthesis, and intramyocellular anabolic signalling in older adults are worthy of investigation. FPH may represent beneficial and sustainable alternative sources of high-quality protein to support skeletal muscle health and anabolism in ageing, without compromising appetite and subsequent energy intake.
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17
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Loh R, Stamatakis E, Folkerts D, Allgrove JE, Moir HJ. Effects of Interrupting Prolonged Sitting with Physical Activity Breaks on Blood Glucose, Insulin and Triacylglycerol Measures: A Systematic Review and Meta-analysis. Sports Med 2020; 50:295-330. [PMID: 31552570 PMCID: PMC6985064 DOI: 10.1007/s40279-019-01183-w] [Citation(s) in RCA: 125] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Physical activity (PA) breaks in sitting time might attenuate metabolic markers relevant to the prevention of type 2 diabetes. OBJECTIVES The primary aim of this paper was to systematically review and meta-analyse trials that compared the effects of breaking up prolonged sitting with bouts of PA throughout the day (INT) versus continuous sitting (SIT) on glucose, insulin and triacylglycerol (TAG) measures. A second aim was to compare the effects of INT versus continuous exercise (EX) on glucose, insulin and TAG measures. METHODS The review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) recommendations. Eligibility criteria consisted of trials comparing INT vs. SIT or INT vs. one bout of EX before or after sitting, in participants aged 18 or above, who were classified as either metabolically healthy or impaired, but not with other major health conditions such as chronic obstructive pulmonary disease or peripheral arterial disease. RESULTS A total of 42 studies were included in the overall review, whereas a total of 37 studies were included in the meta-analysis. There was a standardised mean difference (SMD) of - 0.54 (95% CI - 0.70, - 0.37, p = 0.00001) in favour of INT compared to SIT for glucose. With respect to insulin, there was an SMD of - 0.56 (95% CI - 0.74, - 0.38, p = 0.00001) in favour of INT. For TAG, there was an SMD of - 0.26 (95% CI - 0.44, - 0.09, p = 0.002) in favour of INT. Body mass index (BMI) was associated with glucose responses (β = - 0.05, 95% CI - 0.09, - 0.01, p = 0.01), and insulin (β = - 0.05, 95% CI - 0.10, - 0.006, p = 0.03), but not TAG (β = 0.02, 95% CI - 0.02, 0.06, p = 0.37). When energy expenditure was matched, there was an SMD of - 0.26 (95% CI - 0.50, - 0.02, p = 0.03) in favour of INT for glucose, but no statistically significant SMDs for insulin, i.e. 0.35 (95% CI - 0.37, 1.07, p = 0.35), or TAG i.e. 0.08 (95% CI - 0.22, 0.37, p = 0.62). It is worth noting that there was possible publication bias for TAG outcomes when PA breaks were compared with sitting. CONCLUSION The use of PA breaks during sitting moderately attenuated post-prandial glucose, insulin, and TAG, with greater glycaemic attenuation in people with higher BMI. There was a statistically significant small advantage for PA breaks over continuous exercise for attenuating glucose measures when exercise protocols were energy matched, but no statistically significant differences for insulin and TAG. PROSPERO Registration: CRD42017080982. PROSPERO REGISTRATION CRD42017080982.
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Affiliation(s)
- Roland Loh
- School of Life Sciences, Pharmacy and Chemistry, Faculty of Science, Engineering and Computing, Kingston University, Penrhyn Road, Kingston upon Thames, Surrey, London, KT1 2EE, UK.
| | - Emmanuel Stamatakis
- Charles Perkins Centre, Prevention Research Collaboration, School of Public Health, University of Sydney, Sydney, NSW, Australia
| | - Dirk Folkerts
- School of Life Sciences, Pharmacy and Chemistry, Faculty of Science, Engineering and Computing, Kingston University, Penrhyn Road, Kingston upon Thames, Surrey, London, KT1 2EE, UK.,Faculty of Sport and Exercise Sciences, University of Muenster, Münster, Germany
| | - Judith E Allgrove
- School of Life Sciences, Pharmacy and Chemistry, Faculty of Science, Engineering and Computing, Kingston University, Penrhyn Road, Kingston upon Thames, Surrey, London, KT1 2EE, UK
| | - Hannah J Moir
- School of Life Sciences, Pharmacy and Chemistry, Faculty of Science, Engineering and Computing, Kingston University, Penrhyn Road, Kingston upon Thames, Surrey, London, KT1 2EE, UK.
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18
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Marshall RN, Smeuninx B, Morgan PT, Breen L. Nutritional Strategies to Offset Disuse-Induced Skeletal Muscle Atrophy and Anabolic Resistance in Older Adults: From Whole-Foods to Isolated Ingredients. Nutrients 2020; 12:nu12051533. [PMID: 32466126 PMCID: PMC7284346 DOI: 10.3390/nu12051533] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 05/19/2020] [Accepted: 05/22/2020] [Indexed: 12/14/2022] Open
Abstract
Preserving skeletal muscle mass and functional capacity is essential for healthy ageing. Transient periods of disuse and/or inactivity in combination with sub-optimal dietary intake have been shown to accelerate the age-related loss of muscle mass and strength, predisposing to disability and metabolic disease. Mechanisms underlying disuse and/or inactivity-related muscle deterioration in the older adults, whilst multifaceted, ultimately manifest in an imbalance between rates of muscle protein synthesis and breakdown, resulting in net muscle loss. To date, the most potent intervention to mitigate disuse-induced muscle deterioration is mechanical loading in the form of resistance exercise. However, the feasibility of older individuals performing resistance exercise during disuse and inactivity has been questioned, particularly as illness and injury may affect adherence and safety, as well as accessibility to appropriate equipment and physical therapists. Therefore, optimising nutritional intake during disuse events, through the introduction of protein-rich whole-foods, isolated proteins and nutrient compounds with purported pro-anabolic and anti-catabolic properties could offset impairments in muscle protein turnover and, ultimately, the degree of muscle atrophy and recovery upon re-ambulation. The current review therefore aims to provide an overview of nutritional countermeasures to disuse atrophy and anabolic resistance in older individuals.
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Affiliation(s)
- Ryan N. Marshall
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (R.N.M.); (B.S.); (P.T.M.)
- Medical Research Council-Versus Arthritis Centre for Musculoskeletal Ageing, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Benoit Smeuninx
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (R.N.M.); (B.S.); (P.T.M.)
- Medical Research Council-Versus Arthritis Centre for Musculoskeletal Ageing, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Paul T. Morgan
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (R.N.M.); (B.S.); (P.T.M.)
- Medical Research Council-Versus Arthritis Centre for Musculoskeletal Ageing, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Leigh Breen
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (R.N.M.); (B.S.); (P.T.M.)
- Medical Research Council-Versus Arthritis Centre for Musculoskeletal Ageing, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
- Correspondence: ; Tel.: +44-121-414-4109
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19
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Gonzalez AM, Trexler ET. Effects of Citrulline Supplementation on Exercise Performance in Humans: A Review of the Current Literature. J Strength Cond Res 2020; 34:1480-1495. [DOI: 10.1519/jsc.0000000000003426] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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20
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Eshreif A, Al Batran R, Jamieson KL, Darwesh AM, Gopal K, Greenwell AA, Zlobine I, Aburasayn H, Eaton F, Mulvihill EE, Campbell JE, Seubert JM, Ussher JR. l-Citrulline supplementation improves glucose and exercise tolerance in obese male mice. Exp Physiol 2020; 105:270-281. [PMID: 31802553 DOI: 10.1113/ep088109] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 12/03/2019] [Indexed: 12/13/2022]
Abstract
NEW FINDINGS What is the central question of the study? Does the action of l-citrulline, which has been shown to augment performance in animals and athletes, possibly via increasing mitochondrial function, translate to obese animals, and does this improve glycaemia? What is the main finding and its importance? Chronic supplementation with l-citrulline improves not only exercise capacity, but also glycaemia in obese mice, which would be beneficial as obese individuals are at increased risk for type 2 diabetes. However, l-citrulline supplementation also caused a mild impairment in insulin signalling and insulin tolerance in obese mice. ABSTRACT: l-Citrulline is an organic α-amino acid that has been shown to have a number of salutary actions on whole-body physiology, including reducing muscle wasting and augmenting exercise and muscle performance. The latter has been suggested to arise from elevations in mitochondrial function. Because enhancing mitochondrial function has been proposed as a novel strategy to mitigate insulin resistance, our goal was to determine whether supplementation with l-citrulline could also improve glycaemia in an experimental mouse model of obesity. We hypothesized that l-citrulline treatment would improve glycaemia in obese mice, and this would be associated with elevations in skeletal muscle mitochondrial function. Ten-week-old C57BL/6J mice were fed either a low-fat (10% kcal from lard) or a high-fat (60% kcal from lard) diet, while receiving drinking water supplemented with either vehicle or l-citrulline (0.6 g l-1 ) for 15 weeks. Glucose homeostasis was assessed via glucose/insulin tolerance testing, while in vivo metabolism was assessed via indirect calorimetry, and forced exercise treadmill testing was utilized to assess endurance. As expected, obese mice supplemented with l-citrulline exhibited an increase in exercise capacity, which was associated with an improvement in glucose tolerance. Consistent with augmented mitochondrial function, we observed an increase in whole body oxygen consumption rates in obese mice supplemented with l-citrulline. Surprisingly, l-citrulline supplementation worsened insulin tolerance and reduced insulin signalling in obese mice. Taken together, although l-citrulline supplementation improves both glucose tolerance and exercise capacity in obese mice, caution must be applied with its broad use as a nutraceutical due to a potential deterioration of insulin sensitivity.
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Affiliation(s)
- Amina Eshreif
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Rami Al Batran
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - K Lockhart Jamieson
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Ahmed M Darwesh
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Keshav Gopal
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Amanda A Greenwell
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Igor Zlobine
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Hanin Aburasayn
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Farah Eaton
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - Erin E Mulvihill
- Department of Biochemistry, Microbiology & Immunology, University of Ottawa, Ottawa, ON, Canada.,University of Ottawa Heart Institute, University of Ottawa, Ottawa, ON, Canada
| | | | - John M Seubert
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - John R Ussher
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
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21
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Yang HH, Li XL, Zhang WG, Figueroa A, Chen LH, Qin LQ. Effect of oral L-citrulline on brachial and aortic blood pressure defined by resting status: evidence from randomized controlled trials. Nutr Metab (Lond) 2019; 16:89. [PMID: 31889969 PMCID: PMC6933755 DOI: 10.1186/s12986-019-0415-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 12/12/2019] [Indexed: 02/06/2023] Open
Abstract
Background Experimental evidence indicates that oral L-citrulline (L-Cit) may reduce resting blood pressure (BP) as well as BP responses to exercise and cold exposure (non-resting). However, results from human intervention trials are inconsistent. This study aims to summarize the clinical evidence regarding the effects of L-Cit supplementation on brachial systolic blood pressure (SBP), brachial diastolic blood pressure (DBP), in addition to aortic SBP and aortic DBP at rest and non-resting conditions. Methods Multiple databases including PubMed, Embase, Cochrane library, Web of Science, and Clinical Trials were searched systematically. Randomized controlled trials of human participants were quantitatively meta-analyzed. Results Fourteen trials contained in eight studies were available for quantitative syntheses for brachial BP. Results showed that L-Cit supplementation significantly reduced both brachial SBP (− 4.490 mmHg, 95% CI: − 7.332 to − 1.648, P = 0.002) and brachial DBP (− 3.629 mmHg, 95% CI: − 5.825 to − 1.434, P = 0.001). Nine of the trials were meta-analyzed for aortic BP which showed that L-Cit intervention significantly reduced aortic SBP (− 6.763 mmHg, 95% CI: − 10.991 to − 2.534, P = 0.002), but not aortic DBP (− 3.396 mmHg, 95% CI: − 7.418 to 0.627, P = 0.098). The observed reducing effects of L-Cit appeared stronger for non-resting than for resting brachial SBP (P for difference = 0.044). Conclusion L-Cit supplementation significantly decreased non-resting brachial and aortic SBP. Brachial DBP was significantly lowered by L-Cit regardless of resting status. Given the relatively small number of available trials in the stratified analyses and the potential limitations of these trials, the present findings should be interpreted cautiously and need to be confirmed in future well-designed trials with a larger sample size.
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Affiliation(s)
- Huan-Huan Yang
- 1Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, 215123 China
| | - Xin-Li Li
- 1Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, 215123 China
| | | | - Arturo Figueroa
- 3Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX 79409 USA
| | - Li-Hua Chen
- 1Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, 215123 China
| | - Li-Qiang Qin
- 1Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, 215123 China
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22
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Azizi S, Mahdavi R, Vaghef-Mehrabany E, Maleki V, Karamzad N, Ebrahimi-Mameghani M. Potential roles of Citrulline and watermelon extract on metabolic and inflammatory variables in diabetes mellitus, current evidence and future directions: A systematic review. Clin Exp Pharmacol Physiol 2019; 47:187-198. [PMID: 31612510 DOI: 10.1111/1440-1681.13190] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 09/24/2019] [Accepted: 10/12/2019] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Diabetes mellitus is a prevalent endocrine disorder worldwide. Citrulline is an α-amino acid, which is abundant in watermelon, and a precursor of arginine and nitric oxide. Decreased bioavailability of nitric oxide is associated with insulin resistance. The present systematic review focused on the existing evidence of citrulline and watermelon extract effects on metabolic and inflammatory parameters in diabetes mellitus. METHODS A systematic search of the databases PubMed, Scopus, EMBASE, ProQuest and Google Scholar was conducted for relevant papers published from inception until October 2018. All clinical trials, animal and in vitro studies published in the English language that assessed the role of citrulline and watermelon extract on diabetes mellitus, were eligible. Studies providing inadequate information were excluded. RESULTS Out of 1262 articles we found, only eight articles met the inclusion criteria for analysis. In three studies an increase in the synthesis of nitric oxide was reported with citrulline and watermelon extract supplementation. Four studies showed a significant reduction in blood glucose after supplementation with watermelon extract, and two studies reported a decrease in a number of inflammatory biomarkers following citrulline supplementation. Although citrulline intake caused a significant reduction in HOMA-IR in one study, inconsistent results were revealed on the effects of citrulline and watermelon extract on insulin levels and lipid profile. CONCLUSION Citrulline and watermelon extract could improve nitric oxide synthesis, glycaemic status and inflammation in diabetes mellitus. However, further studies are required to shed light on the underlying mechanisms.
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Affiliation(s)
- Samaneh Azizi
- Department of Biochemistry and Dietetics, Faculty of Nutrition and Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Reza Mahdavi
- Nutrition Research Center, Department of Biochemistry and Diet Therapy, School of Nutrition & Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Elnaz Vaghef-Mehrabany
- Department of Biochemistry and Dietetics, Faculty of Nutrition and Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Vahid Maleki
- Department of Biochemistry and Dietetics, Faculty of Nutrition and Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Nahid Karamzad
- Department of Biochemistry and Dietetics, Faculty of Nutrition and Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mehrangiz Ebrahimi-Mameghani
- Nutrition Research Center, Department of Biochemistry and Diet Therapy, School of Nutrition & Food Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
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Trexler ET, Keith DS, Lucero AA, Stoner L, Schwartz TA, Persky AM, Ryan ED, Smith-Ryan AE. Effects of Citrulline Malate and Beetroot Juice Supplementation on Energy Metabolism and Blood Flow During Submaximal Resistance Exercise. J Diet Suppl 2019; 17:698-717. [DOI: 10.1080/19390211.2019.1650866] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Eric T. Trexler
- Human Movement Science Curriculum, Department of Allied Health Sciences, University of North Carolina, Chapel Hill, NC, USA
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA
| | - Dale S. Keith
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA
| | - Adam A. Lucero
- School of Sport, Exercise and Nutrition, Massey University, Wellington, NZ
| | - Lee Stoner
- Human Movement Science Curriculum, Department of Allied Health Sciences, University of North Carolina, Chapel Hill, NC, USA
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA
| | - Todd A. Schwartz
- Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
| | - Adam M. Persky
- Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Eric D. Ryan
- Human Movement Science Curriculum, Department of Allied Health Sciences, University of North Carolina, Chapel Hill, NC, USA
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA
| | - Abbie E. Smith-Ryan
- Human Movement Science Curriculum, Department of Allied Health Sciences, University of North Carolina, Chapel Hill, NC, USA
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA
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24
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Supplementary Nitric Oxide Donors and Exercise as Potential Means to Improve Vascular Health in People with Type 1 Diabetes: Yes to NO? Nutrients 2019; 11:nu11071571. [PMID: 31336832 PMCID: PMC6682901 DOI: 10.3390/nu11071571] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 06/26/2019] [Accepted: 07/10/2019] [Indexed: 12/16/2022] Open
Abstract
Type 1 diabetes (T1D) is associated with a greater occurrence of cardiovascular pathologies. Vascular dysfunction has been shown at the level of the endothelial layers and failure to maintain a continuous pool of circulating nitric oxide (NO) has been implicated in the progression of poor vascular health. Biochemically, NO can be produced via two distinct yet inter-related pathways that involve an upregulation in the enzymatic activity of nitric oxide synthase (NOS). These pathways can be split into an endogenous oxygen-dependent pathway i.e., the catabolism of the amino acid L-arginine to L-citrulline concurrently yielding NO in the process, and an exogenous oxygen-independent one i.e., the conversion of exogenous inorganic nitrate to nitrite and subsequently NO in a stepwise fashion. Although a body of research has explored the vascular responses to exercise and/or compounds known to stimulate NOS and subsequently NO production, there is little research applying these findings to individuals with T1D, for whom preventative strategies that alleviate or at least temper vascular pathologies are critical foci for long-term risk mitigation. This review addresses the proposed mechanisms responsible for vascular dysfunction, before exploring the potential mechanisms by which exercise, and two supplementary NO donors may provide vascular benefits in T1D.
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25
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Le Roux-Mallouf T, Pelen F, Vallejo A, Halimaoui I, Doutreleau S, Verges S. Effect of chronic nitrate and citrulline supplementation on vascular function and exercise performance in older individuals. Aging (Albany NY) 2019; 11:3315-3332. [PMID: 31141497 PMCID: PMC6555465 DOI: 10.18632/aging.101984] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 05/17/2019] [Indexed: 12/11/2022]
Abstract
Increased nitric oxide (NO) bioavailability may improve exercise performance and vascular function. It remains unclear whether older adults who experience a decreased NO bioavailability may benefit from chronic NO precursor supplementation. This randomised, double-blind, trial aims to assess the effect of chronic NO precursor intake on vascular function and exercise performance in older adults (60-70 years old). Twenty-four healthy older adults (12 females) performed vascular function assessment and both local (knee extensions) and whole-body (incremental cycling) exercise tests to exhaustion before and after one month of daily intake of a placebo (PLA) or a nitrate-rich salad and citrulline (N+C, 520mg nitrate and 6g citrulline) drink. Arterial blood pressure (BP) and stiffness, post-ischemic, hypercapnic and hypoxic vascular responses were evaluated. Prefrontal cortex and quadriceps oxygenation was monitored by near-infrared spectroscopy. N+C supplementation reduced mean BP (-3.3mmHg; p=0.047) without altering other parameters of vascular function and oxygenation kinetics. N+C supplementation reduced heart rate and oxygen consumption during submaximal cycling and increased maximal power output by 5.2% (p<0.05), but had no effect on knee extension exercise performance. These results suggest that chronic NO precursor supplementation in healthy older individuals can reduce resting BP and increase cycling performance by improving cardiorespiratory responses.
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Affiliation(s)
| | - Felix Pelen
- Université Grenoble Alpes, Inserm, HP2 Laboratory, Grenoble F-38000, France
| | - Angela Vallejo
- Université Grenoble Alpes, Inserm, HP2 Laboratory, Grenoble F-38000, France
| | - Idir Halimaoui
- Université Grenoble Alpes, Inserm, HP2 Laboratory, Grenoble F-38000, France
| | - Stéphane Doutreleau
- Université Grenoble Alpes, Inserm, HP2 Laboratory, Grenoble F-38000, France
- Sport and Pathologies Unit, Grenoble Alpes University Hospital, Hôpital Michallon, Grenoble F-38042, France
| | - Samuel Verges
- Université Grenoble Alpes, Inserm, HP2 Laboratory, Grenoble F-38000, France
- Sport and Pathologies Unit, Grenoble Alpes University Hospital, Hôpital Michallon, Grenoble F-38042, France
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26
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Impact of 3-week citrulline supplementation on postprandial protein metabolism in malnourished older patients: The Ciproage randomized controlled trial. Clin Nutr 2019; 38:564-574. [DOI: 10.1016/j.clnu.2018.02.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/07/2018] [Accepted: 02/12/2018] [Indexed: 12/27/2022]
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27
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Bowden Davies KA, Pickles S, Sprung VS, Kemp GJ, Alam U, Moore DR, Tahrani AA, Cuthbertson DJ. Reduced physical activity in young and older adults: metabolic and musculoskeletal implications. Ther Adv Endocrinol Metab 2019; 10:2042018819888824. [PMID: 31803464 PMCID: PMC6878603 DOI: 10.1177/2042018819888824] [Citation(s) in RCA: 112] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 10/22/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Although the health benefits of regular physical activity and exercise are well established and have been incorporated into national public health recommendations, there is a relative lack of understanding pertaining to the harmful effects of physical inactivity. Experimental paradigms including complete immobilization and bed rest are not physiologically representative of sedentary living. A useful 'real-world' approach to contextualize the physiology of societal downward shifts in physical activity patterns is that of short-term daily step reduction. RESULTS Step-reduction studies have largely focused on musculoskeletal and metabolic health parameters, providing relevant disease models for metabolic syndrome, type 2 diabetes (T2D), nonalcoholic fatty liver disease (NAFLD), sarcopenia and osteopenia/osteoporosis. In untrained individuals, even a short-term reduction in physical activity has a significant impact on skeletal muscle protein and carbohydrate metabolism, causing anabolic resistance and peripheral insulin resistance, respectively. From a metabolic perspective, short-term inactivity-induced peripheral insulin resistance in skeletal muscle and adipose tissue, with consequent liver triglyceride accumulation, leads to hepatic insulin resistance and a characteristic dyslipidaemia. Concomitantly, various inactivity-related factors contribute to a decline in function; a reduction in cardiorespiratory fitness, muscle mass and muscle strength. CONCLUSIONS Physical inactivity maybe particularly deleterious in certain patient populations, such as those at high risk of T2D or in the elderly, considering concomitant sarcopenia or osteoporosis. The effects of short-term physical inactivity (with step reduction) are reversible on resumption of habitual physical activity in younger people, but less so in older adults. Nutritional interventions and resistance training offer potential strategies to prevent these deleterious metabolic and musculoskeletal effects. IMPACT Individuals at high risk of/with cardiometabolic disease and older adults may be more prone to these acute periods of inactivity due to acute illness or hospitalization. Understanding the risks is paramount to implementing countermeasures.
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Affiliation(s)
| | - Samuel Pickles
- Institute of Ageing and Chronic Disease,
University of Liverpool, Liverpool, UK
- Obesity and Endocrinology Research Group,
Aintree University Hospital NHS Foundation Trust, Liverpool, UK
| | - Victoria S. Sprung
- Research Institute for Sport and Exercise
Science, Liverpool John Moores University, Liverpool, UK
- Institute of Ageing and Chronic Disease,
University of Liverpool, Liverpool, UK
- Obesity and Endocrinology Research Group,
Aintree University Hospital NHS Foundation Trust, Liverpool, UK
| | - Graham J. Kemp
- Institute of Ageing and Chronic Disease,
University of Liverpool, Liverpool, UK
- Liverpool Magnetic Resonance Imaging Centre
(LiMRIC), University of Liverpool, Liverpool, UK
| | - Uazman Alam
- Institute of Ageing and Chronic Disease,
University of Liverpool, Liverpool, UK
- Obesity and Endocrinology Research Group,
Aintree University Hospital NHS Foundation Trust, Liverpool, UK
- Pain Research Institute, University of
Liverpool, Liverpool, UK
- Division of Endocrinology, Diabetes and
Gastroenterology, University of Manchester, Manchester, UK
- Department of Diabetes and Endocrinology, Royal
Liverpool and Broadgreen University NHS Hospitals Trust, Liverpool, UK
| | - Daniel R. Moore
- Faculty of Kinesiology and Physical Education,
University of Toronto, Toronto, ON, Canada
| | - Abd A. Tahrani
- Institute of Metabolism and Systems Research,
College of Medical and Dental Sciences, University of Birmingham,
Birmingham, UK
- Centre of Endocrinology, Diabetes and
Metabolism (CEDAM), Birmingham Health Partners, Birmingham UK
- Department of Diabetes and Endocrinology,
University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Daniel J. Cuthbertson
- Institute of Ageing and Chronic Disease,
University of Liverpool, Liverpool, UK
- Obesity and Endocrinology Research Group,
Aintree University Hospital NHS Foundation Trust, Liverpool, UK
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28
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Citrulline in health and disease. Review on human studies. Clin Nutr 2018; 37:1823-1828. [DOI: 10.1016/j.clnu.2017.10.009] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 09/28/2017] [Accepted: 10/09/2017] [Indexed: 12/13/2022]
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29
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Moore DR, Kelly RP, Devries MC, Churchward-Venne TA, Phillips SM, Parise G, Johnston AP. Low-load resistance exercise during inactivity is associated with greater fibre area and satellite cell expression in older skeletal muscle. J Cachexia Sarcopenia Muscle 2018; 9:747-754. [PMID: 29761654 PMCID: PMC6104111 DOI: 10.1002/jcsm.12306] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 03/07/2018] [Accepted: 03/21/2018] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Age-related sarcopenia is accelerated by physical inactivity. Low-load resistance exercise (LLRE) counters inactivity-induced muscle atrophy in older adults, but changes in muscle fibre morphology are unstudied. We aimed to determine the impact of LLRE during short-term inactivity (step-reduction) on muscle fibre size and capillarity as well as satellite cell (SC) content in older skeletal muscle. METHODS Fourteen older (~71 years) male adults underwent 14 days of step reduction (<1500 steps/day) while performing six sessions of LLRE (~30% maximal strength) with one leg (SR + EX) while the contralateral leg served as an untrained control (SR). Seven healthy ambulatory age-matched male adults (~69 years) served as a comparator group (COM). Muscle biopsies were taken from the vastus lateralis after 14 days, and immunohistochemical analysis was performed to determine muscle fibre cross-sectional area (CSA), myonuclear content, SC content (PAX7+ cells), and total (C:F) and fibre type-specific (C:Fi) capillary-to-fibre ratios. RESULTS Type I and II fibre CSA was greater in SR + EX compared with SR. Whereas there were no differences across fibre types between SR + EX and CON, type II fibre CSA was significantly lower in SR compared with COM. Type II myonuclear domain was greater in SR + EX compared with COM and SR. Pax7+ cells associated with type I and II fibres were lower in SR compared with SR + EX. Type II PAX7+ cells were also lower in SR compared with COM with a similar trend for type I fibres. There were trends for a lower C:Fi in SR compared with SR + EX for both fibre types with no differences for each compared with COM. CONCLUSIONS Minimal LLRE during a period of decreased physical activity is associated with greater muscle fibre CSA, SC content, and capillarization. These results support the use of LLRE as an effective countermeasure to inactivity-induced alterations in muscle morphology with age.
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Affiliation(s)
- Daniel R Moore
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada
| | - Ryan P Kelly
- Department of Applied Human Sciences, University of Prince Edward Island, Charlottetown, PE, Canada
| | | | | | - Stuart M Phillips
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Gianni Parise
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Adam P Johnston
- Department of Applied Human Sciences, University of Prince Edward Island, Charlottetown, PE, Canada
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30
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Allerton TD, Proctor DN, Stephens JM, Dugas TR, Spielmann G, Irving BA. l-Citrulline Supplementation: Impact on Cardiometabolic Health. Nutrients 2018; 10:nu10070921. [PMID: 30029482 PMCID: PMC6073798 DOI: 10.3390/nu10070921] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 07/09/2018] [Accepted: 07/16/2018] [Indexed: 12/12/2022] Open
Abstract
Diminished bioavailability of nitric oxide (NO), the gaseous signaling molecule involved in the regulation of numerous vital biological functions, contributes to the development and progression of multiple age- and lifestyle-related diseases. While l-arginine is the precursor for the synthesis of NO by endothelial-nitric oxide synthase (eNOS), oral l-arginine supplementation is largely ineffective at increasing NO synthesis and/or bioavailability for a variety of reasons. l-citrulline, found in high concentrations in watermelon, is a neutral alpha-amino acid formed by enzymes in the mitochondria that also serves as a substrate for recycling l-arginine. Unlike l-arginine, l-citrulline is not quantitatively extracted from the gastrointestinal tract (i.e., enterocytes) or liver and its supplementation is therefore more effective at increasing l-arginine levels and NO synthesis. Supplementation with l-citrulline has shown promise as a blood pressure lowering intervention (both resting and stress-induced) in adults with pre-/hypertension, with pre-clinical (animal) evidence for atherogenic-endothelial protection. Preliminary evidence is also available for l-citrulline-induced benefits to muscle and metabolic health (via vascular and non-vascular pathways) in susceptible/older populations. In this review, we examine the impact of supplementing this important urea cycle intermediate on cardiovascular and metabolic health outcomes and identify future directions for investigating its therapeutic impact on cardiometabolic health.
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Affiliation(s)
| | - David N Proctor
- Department of Kinesiology, Pennsylvania State University, University Park, PA 16802, USA.
| | | | - Tammy R Dugas
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.
| | - Guillaume Spielmann
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
- Department of Kinesiology, Louisiana State University, Baton Rouge, LA 70803, USA.
| | - Brian A Irving
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
- Department of Kinesiology, Louisiana State University, Baton Rouge, LA 70803, USA.
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31
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Mertz KH, Bülow J, Holm L. Contrast-enhanced ultrasound using bolus injections of contrast agent for assessment of postprandial microvascular blood volume in human skeletal muscle. Clin Physiol Funct Imaging 2017; 38:864-871. [DOI: 10.1111/cpf.12496] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 12/05/2017] [Indexed: 12/01/2022]
Affiliation(s)
- Kenneth H. Mertz
- Institute of Sports Medicine and Orthopedic Surgery M81; Bispebjerg Hospital; Birmingham UK
| | - Jacob Bülow
- Institute of Sports Medicine and Orthopedic Surgery M81; Bispebjerg Hospital; Birmingham UK
| | - Lars Holm
- Institute of Sports Medicine and Orthopedic Surgery M81; Bispebjerg Hospital; Birmingham UK
- School of Sport; Exercise and Rehabilitation Sciences; University of Birmingham; Birmingham UK
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32
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Mitchell WK, Phillips BE, Wilkinson DJ, Williams JP, Rankin D, Lund JN, Smith K, Atherton PJ. Supplementing essential amino acids with the nitric oxide precursor, l-arginine, enhances skeletal muscle perfusion without impacting anabolism in older men. Clin Nutr 2017; 36:1573-1579. [PMID: 27746000 DOI: 10.1016/j.clnu.2016.09.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 05/22/2016] [Accepted: 09/30/2016] [Indexed: 01/01/2023]
Abstract
Postprandial limb blood flow and skeletal muscle microvascular perfusion reduce with aging. Here we tested the impact of providing bolus essential amino acids (EAA) in the presence and absence of the nitric oxide precursor, l-Arginine (ARG), upon skeletal muscle blood flow and anabolism in older men. Healthy young (YOUNG: 19.7 ± 0.5 y, N = 8) and older men (OLD, 70 ± 0.8 y, N = 8) received 15 g EAA or (older only) 15 g EAA +3 g ARG (OLD-ARG, 69.2 ± 1.2 y, N = 8). We quantified responses in muscle protein synthesis (MPS; incorporation of 13C phenylalanine into myofibrillar proteins), leg and muscle microvascular blood flow (Doppler/contrast enhanced ultrasound (CEUS)) and insulin/EAA in response to EEA ± ARG. Plasma EAA increased similarly across groups but argininemia was evident solely in OLD-ARG (∼320 mmol, 65 min post feed); increases in plasma insulin (to ∼13 IU ml-1) were similar across groups. Increases in femoral flow were evident in YOUNG >2 h after feeding; these effects were blunted in OLD and OLD-ARG. Increases in microvascular blood volume (MBV) occurred only in YOUNG and these effects were isolated to the early postprandial phase (+45% at ∼45 min after feeding) coinciding with detectable arterio-venous differences in EAA reflecting net uptake by muscle. Increases in microvascular flow velocity (MFV) and tissue perfusion (MBV × MFV) occurred (∼2 h) in YOUNG and OLD-ARG, but not OLD. Postprandial protein accretion was greater in YOUNG than OLD or OLD-ARG; the latter two groups being indistinguishable. Therefore, ARG rescues aspects of muscle perfusion in OLD without impacting anabolic blunting, perhaps due to the "rescue" being beyond the period of active EAA-uptake.
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Affiliation(s)
- W Kyle Mitchell
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, DE22 3DT, UK
| | - Bethan E Phillips
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, DE22 3DT, UK
| | - Daniel J Wilkinson
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, DE22 3DT, UK
| | - John P Williams
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, DE22 3DT, UK
| | - Debbie Rankin
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, DE22 3DT, UK
| | - Jonathan N Lund
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, DE22 3DT, UK
| | - Kenneth Smith
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, DE22 3DT, UK
| | - Philip J Atherton
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Medicine, University of Nottingham, Derby, DE22 3DT, UK.
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da Silva DK, Jacinto JL, de Andrade WB, Roveratti MC, Estoche JM, Balvedi MCW, de Oliveira DB, da Silva RA, Aguiar AF. Citrulline Malate Does Not Improve Muscle Recovery after Resistance Exercise in Untrained Young Adult Men. Nutrients 2017; 9:E1132. [PMID: 29057836 PMCID: PMC5691748 DOI: 10.3390/nu9101132] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 10/03/2017] [Accepted: 10/10/2017] [Indexed: 01/21/2023] Open
Abstract
The effects of citrulline malate (CM) on muscle recovery from resistance exercise remains unknown. We aimed to determine if citrulline malate supplementation improves muscle recovery after a single session of high-intensity resistance exercise (RE) in untrained young adult men. Nine young adult men (24.0 ± 3.3 years) participated in a double-blind crossover study in which they received 6 g of CM and placebo (PL) on two occasions, separated by a seven-day washout period. Each occasion consisted of a single session of high-intensity RE (0 h) and three subsequent fatigue tests sessions (at 24, 48, and 72 h) to assess the time course of muscle recovery. During the tests sessions, we assessed the following variables: number of maximum repetitions, electromyographic signal (i.e., root mean square (RMS) and median frequency (MF)), muscle soreness and perceived exertion, as well as blood levels of creatine kinase (CK), lactate, insulin, and testosterone:cortisol ratio. CK levels increased at 24 h post-exercise and remained elevate at 48 and 72 h, with no difference between CM and PL conditions. Muscle soreness increased at 24 h post-exercise, which progressively returned to baseline at 72 h in both conditions. Lactate levels increased immediately post-exercise and remained elevated at 24, 48, and 72 h in both conditions. No significant treatment × time interaction was found for all dependents variables (maximum repetitions, perceived exertion, CK, lactate, RMS, MF, and testosterone:cortisol ratio) during the recovery period. In conclusion, our data indicate that CM supplementation (single 6 g dose pre-workout) does not improve the muscle recovery process following a high-intensity RE session in untrained young adult men.
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Affiliation(s)
- Douglas K da Silva
- Center for Research in Health Sciences, North University of Paraná (UNOPAR), 675 Paris Ave., Londrina 86041-120, Brazil.
| | - Jeferson L Jacinto
- Center for Research in Health Sciences, North University of Paraná (UNOPAR), 675 Paris Ave., Londrina 86041-120, Brazil.
| | - Walquiria B de Andrade
- Center for Research in Health Sciences, North University of Paraná (UNOPAR), 675 Paris Ave., Londrina 86041-120, Brazil.
| | - Mirela C Roveratti
- Center for Research in Health Sciences, North University of Paraná (UNOPAR), 675 Paris Ave., Londrina 86041-120, Brazil.
| | - José M Estoche
- Center for Research in Health Sciences, North University of Paraná (UNOPAR), 675 Paris Ave., Londrina 86041-120, Brazil.
| | - Mario C W Balvedi
- Center for Research in Health Sciences, North University of Paraná (UNOPAR), 675 Paris Ave., Londrina 86041-120, Brazil.
| | - Douglas B de Oliveira
- Center for Research in Health Sciences, North University of Paraná (UNOPAR), 675 Paris Ave., Londrina 86041-120, Brazil.
| | - Rubens A da Silva
- Laboratory of Functional Evaluation and Human Motor Performance, LAFUP, Center for Research in Health Sciences, North Univeristy of Paraná (UNOPAR), 675 Paris Ave., Londrina 86041-120, Brazil.
- Département des Sciences de la Santé, Programme de Physiothérapie de L'université McGill Offert en Extension à L'UNIVERSITÉ du Québec à Chicoutimi (UQAC), 555 boul. De L'université, ville du Saguenay, Québec, QC G7H 5B8, Canada.
| | - Andreo F Aguiar
- Center for Research in Health Sciences, North University of Paraná (UNOPAR), 675 Paris Ave., Londrina 86041-120, Brazil.
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Gonzales JU, Raymond A, Ashley J, Kim Y. Does l-citrulline supplementation improve exercise blood flow in older adults? Exp Physiol 2017; 102:1661-1671. [PMID: 28940638 PMCID: PMC5999519 DOI: 10.1113/ep086587] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 09/18/2017] [Indexed: 12/12/2022]
Abstract
NEW FINDINGS What is the central question of this study? Does short-term supplementation with l-citrulline in order to increase l-arginine improve exercise blood flow and peripheral dilatation responses to exercise in older adults? What is the main finding and its importance? l-Citrulline increased femoral blood flow by 11% and vascular conductance by 14% during lower-limb exercise in older men, whereas no changes were observed in older women. This modest improvement in bulk muscle blood flow in older men has implications for altering muscle metabolism that may result in enhanced exercise tolerance in older adults. l-Citrulline (Cit) increases l-arginine (Arg), the primary substrate for nitric oxide biosynthesis. We tested the hypothesis that muscle blood flow during exercise would be enhanced by Cit supplementation in older adults. Femoral artery blood flow was measured during calf exercise using Doppler ultrasound, and vascular conductance (FVC) was calculated in 25 older adults (13 women and 12 men) before and after 14 days of Cit (6 g day-1 ) and placebo (maltodextrin) in a randomized, double-blind, crossover study. Plasma [Arg] and resting blood pressure were also measured before and after each condition. Women and men were analysed separately because of significant sex-by-condition interactions for the change in exercise blood flow and FVC. Plasma [Arg] was increased by 30 and 35% after Cit (P < 0.01) in women and men, respectively, with no change after placebo. Citrulline lowered diastolic blood pressure in men (75 ± 9 versus 71 ± 6 mmHg, P = 0.02), but this variable remained unchanged in women. Blood flow and FVC during exercise at higher workloads were increased after Cit in men (flow, 521 ± 134 versus 584 ± 166 ml min-1 , P = 0.04; FVC, 5.0 ± 1.5 versus 5.8 ± 1.7 m, min mmHg-1 , P = 0.01) but were not different after placebo. These variables were not altered by Cit in women. Adjusting for baseline diastolic blood pressure removed (P = 0.10) the difference in FBF and FVC following Cit in men. These results indicate that l-citrulline has a modest effect of improving muscle blood flow during submaximal exercise in older men.
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Affiliation(s)
- Joaquin U Gonzales
- Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, USA
| | - Andrea Raymond
- Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, USA
| | - John Ashley
- Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, USA
| | - Youngdeok Kim
- Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX, USA
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Deane CS, Wilkinson DJ, Phillips BE, Smith K, Etheridge T, Atherton PJ. "Nutraceuticals" in relation to human skeletal muscle and exercise. Am J Physiol Endocrinol Metab 2017; 312:E282-E299. [PMID: 28143855 PMCID: PMC5406990 DOI: 10.1152/ajpendo.00230.2016] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 01/25/2017] [Accepted: 01/25/2017] [Indexed: 12/16/2022]
Abstract
Skeletal muscles have a fundamental role in locomotion and whole body metabolism, with muscle mass and quality being linked to improved health and even lifespan. Optimizing nutrition in combination with exercise is considered an established, effective ergogenic practice for athletic performance. Importantly, exercise and nutritional approaches also remain arguably the most effective countermeasure for muscle dysfunction associated with aging and numerous clinical conditions, e.g., cancer cachexia, COPD, and organ failure, via engendering favorable adaptations such as increased muscle mass and oxidative capacity. Therefore, it is important to consider the effects of established and novel effectors of muscle mass, function, and metabolism in relation to nutrition and exercise. To address this gap, in this review, we detail existing evidence surrounding the efficacy of a nonexhaustive list of macronutrient, micronutrient, and "nutraceutical" compounds alone and in combination with exercise in relation to skeletal muscle mass, metabolism (protein and fuel), and exercise performance (i.e., strength and endurance capacity). It has long been established that macronutrients have specific roles and impact upon protein metabolism and exercise performance, (i.e., protein positively influences muscle mass and protein metabolism), whereas carbohydrate and fat intakes can influence fuel metabolism and exercise performance. Regarding novel nutraceuticals, we show that the following ones in particular may have effects in relation to 1) muscle mass/protein metabolism: leucine, hydroxyl β-methylbutyrate, creatine, vitamin-D, ursolic acid, and phosphatidic acid; and 2) exercise performance: (i.e., strength or endurance capacity): hydroxyl β-methylbutyrate, carnitine, creatine, nitrates, and β-alanine.
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Affiliation(s)
- Colleen S Deane
- Medical Research Council-Arthritis Research UK Centre of Excellence for Musculoskeletal Ageing Research and Clinical, Metabolic, and Molecular Physiology, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
- Faculty of Health and Social Science, Bournemouth University, Bournemouth, United Kingdom; and
- Department of Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Daniel J Wilkinson
- Medical Research Council-Arthritis Research UK Centre of Excellence for Musculoskeletal Ageing Research and Clinical, Metabolic, and Molecular Physiology, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
| | - Bethan E Phillips
- Medical Research Council-Arthritis Research UK Centre of Excellence for Musculoskeletal Ageing Research and Clinical, Metabolic, and Molecular Physiology, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
| | - Kenneth Smith
- Medical Research Council-Arthritis Research UK Centre of Excellence for Musculoskeletal Ageing Research and Clinical, Metabolic, and Molecular Physiology, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom
| | - Timothy Etheridge
- Department of Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Philip J Atherton
- Medical Research Council-Arthritis Research UK Centre of Excellence for Musculoskeletal Ageing Research and Clinical, Metabolic, and Molecular Physiology, University of Nottingham, Royal Derby Hospital, Derby, United Kingdom;
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Synergistic effects of citrulline supplementation and exercise on performance in male rats: evidence for implication of protein and energy metabolisms. Clin Sci (Lond) 2017; 131:775-790. [PMID: 28250083 DOI: 10.1042/cs20170088] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 11/17/2022]
Abstract
Background: Exercise and citrulline (CIT) are both regulators of muscle protein metabolism. However, the combination of both has been under-studied yet may have synergistic effects on muscle metabolism and performance. Methods: Three-month-old healthy male rats were randomly assigned to be fed ad libitum for 4 weeks with either a citrulline-enriched diet (1 g·kg-1·day-1) (CIT) or an isonitrogenous standard diet (by addition of nonessential amino acid) (Ctrl) and trained (running on treadmill 5 days·week-1) (ex) or not. Maximal endurance activity and body composition were assessed, and muscle protein metabolism (protein synthesis, proteomic approach) and energy metabolism [energy expenditure, mitochondrial metabolism] were explored. Results: Body composition was affected by exercise but not by CIT supplementation. Endurance training was associated with a higher maximal endurance capacity than sedentary groups (P<0.001), and running time was 14% higher in the CITex group than the Ctrlex group (139±4 min versus 122±6 min, P<0.05). Both endurance training and CIT supplementation alone increased muscle protein synthesis (by +27% and +33%, respectively, versus Ctrl, P<0.05) with an additive effect (+48% versus Ctrl, P<0.05). Mitochondrial metabolism was modulated by exercise but not directly by CIT supplementation. However, the proteomic approach demonstrated that CIT supplementation was able to affect energy metabolism, probably due to activation of pathways generating acetyl-CoA. Conclusion: CIT supplementation and endurance training in healthy male rats modulates both muscle protein and energy metabolisms, with synergic effects on an array of parameters, including performance and protein synthesis.
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Figueroa A, Wong A, Jaime SJ, Gonzales JU. Influence of L-citrulline and watermelon supplementation on vascular function and exercise performance. Curr Opin Clin Nutr Metab Care 2017; 20:92-98. [PMID: 27749691 DOI: 10.1097/mco.0000000000000340] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW L-Citrulline, either synthetic or in watermelon, may improve vascular function through increased L-arginine bioavailability and nitric oxide synthesis. This article analyses potential vascular benefits of L-citrulline and watermelon supplementation at rest and during exercise. RECENT FINDINGS There is clear evidence that acute L-citrulline ingestion increases plasma L-arginine, the substrate for endothelial nitric oxide synthesis. However, the subsequent acute improvement in nitric oxide production and mediated vasodilation is inconsistent, which likely explains the inability of acute L-citrulline or watermelon to improve exercise tolerance. Recent studies have shown that chronic L-citrulline supplementation increases nitric oxide synthesis, decreases blood pressure, and may increase peripheral blood flow. These changes are paralleled by improvements in skeletal muscle oxygenation and performance during endurance exercise. The antihypertensive effect of L-citrulline/watermelon supplementation is evident in adults with prehypertension or hypertension, but not in normotensives. However, L-citrulline supplementation may attenuate the blood pressure response to exercise in normotensive men. SUMMARY The beneficial vascular effects of L-citrulline/watermelon supplementation may stem from improvements in the L-arginine/nitric oxide pathway. Reductions in resting blood pressure with L-citrulline/watermelon supplementation may have major implications for individuals with prehypertension and hypertension. L-Citrulline supplementation, but not acute ingestion, have shown to improve exercise performance in young healthy adults.
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Affiliation(s)
- Arturo Figueroa
- aDepartment of Nutrition, Food, and Exercise Sciences, Florida State University, Tallahassee, Florida bDepartment of Health and Human Performance, Marymount University, Arlington, Virginia cDepartment of Kinesiology and Sport Management, Texas Tech University, Lubbock, Texas, USA
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Le Plénier S, Goron A, Sotiropoulos A, Archambault E, Guihenneuc C, Walrand S, Salles J, Jourdan M, Neveux N, Cynober L, Moinard C. Citrulline directly modulates muscle protein synthesis via the PI3K/MAPK/4E-BP1 pathway in a malnourished state: evidence from in vivo, ex vivo, and in vitro studies. Am J Physiol Endocrinol Metab 2017; 312:E27-E36. [PMID: 27827806 DOI: 10.1152/ajpendo.00203.2016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 10/13/2016] [Accepted: 10/18/2016] [Indexed: 12/16/2022]
Abstract
Citrulline (CIT) is an endogenous amino acid produced by the intestine. Recent literature has consistently shown CIT to be an activator of muscle protein synthesis (MPS). However, the underlying mechanism is still unknown. Our working hypothesis was that CIT might regulate muscle homeostasis directly through the mTORC1/PI3K/MAPK pathways. Because CIT undergoes both interorgan and intraorgan trafficking and metabolism, we combined three approaches: in vivo, ex vivo, and in vitro. Using a model of malnourished aged rats, CIT supplementation activated the phosphorylation of S6K1 and 4E-BP1 in muscle. Interestingly, the increase in S6K1 phosphorylation was positively correlated (P < 0.05) with plasma CIT concentration. In a model of isolated incubated skeletal muscle from malnourished rats, CIT enhanced MPS (from 30 to 80% CIT vs. Ctrl, P < 0.05), and the CIT effect was abolished in the presence of wortmannin, rapamycin, and PD-98059. In vitro, on myotubes in culture, CIT led to a 2.5-fold increase in S6K1 phosphorylation and a 1.5-fold increase in 4E-BP1 phosphorylation. Both rapamycin and PD-98059 inhibited the CIT effect on S6K1, whereas only LY-294002 inhibited the CIT effect on both S6K1 and 4E-BP1. These findings show that CIT is a signaling agent for muscle homeostasis, suggesting a new role of the intestine in muscle mass control.
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Affiliation(s)
- Servane Le Plénier
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France;
| | - Arthur Goron
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Athanassia Sotiropoulos
- Centre National de la Recherche Scientifique UMR 8104, Institut Cochin, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Eliane Archambault
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Chantal Guihenneuc
- Laboratoire d'épidémiologie environnementale, EA 4064, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Stéphane Walrand
- Unité de Nutrition humaine, UMR 1019, Institut National de la Recherche Agronomique/Université d'Auvergne, Centre de Recherche en Nutrition Humaine, Auvergne, Clermont-Ferrand, France; and
| | - Jérome Salles
- Unité de Nutrition humaine, UMR 1019, Institut National de la Recherche Agronomique/Université d'Auvergne, Centre de Recherche en Nutrition Humaine, Auvergne, Clermont-Ferrand, France; and
| | - Marion Jourdan
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Nathalie Neveux
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Luc Cynober
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
- Service de Biochimie interhospitalier Cochin et Hôtel-Dieu, GH Hôpitaux universitaire Paris Centre, AP-HP, Paris, France
| | - Christophe Moinard
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
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Kouw IWK, Cermak NM, Burd NA, Churchward-Venne TA, Senden JM, Gijsen AP, van Loon LJC. Sodium nitrate co-ingestion with protein does not augment postprandial muscle protein synthesis rates in older, type 2 diabetes patients. Am J Physiol Endocrinol Metab 2016; 311:E325-34. [PMID: 27221118 DOI: 10.1152/ajpendo.00122.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 05/19/2016] [Indexed: 12/24/2022]
Abstract
The age-related anabolic resistance to protein ingestion is suggested to be associated with impairments in insulin-mediated capillary recruitment and postprandial muscle tissue perfusion. The present study investigated whether dietary nitrate co-ingestion with protein improves muscle protein synthesis in older, type 2 diabetes patients. Twenty-four men with type 2 diabetes (72 ± 1 yr, 26.7 ± 1.4 m/kg(2) body mass index, 7.3 ± 0.4% HbA1C) received a primed continuous infusion of l-[ring-(2)H5]phenylalanine and l-[1-(13)C]leucine and ingested 20 g of intrinsically l-[1-(13)C]phenylalanine- and l-[1-(13)C]leucine-labeled protein with (PRONO3) or without (PRO) sodium nitrate (0.15 mmol/kg). Blood and muscle samples were collected to assess protein digestion and absorption kinetics and postprandial muscle protein synthesis rates. Upon protein ingestion, exogenous phenylalanine appearance rates increased in both groups (P < 0.001), resulting in 55 ± 2% and 53 ± 2% of dietary protein-derived amino acids becoming available in the circulation over the 5h postprandial period in the PRO and PRONO3 groups, respectively. Postprandial myofibrillar protein synthesis rates based on l-[ring-(2)H5]phenylalanine did not differ between groups (0.025 ± 0.004 and 0.021 ± 0.007%/h over 0-2 h and 0.032 ± 0.004 and 0.030 ± 0.003%/h over 2-5 h in PRO and PRONO3, respectively, P = 0.7). No differences in incorporation of dietary protein-derived l-[1-(13)C]phenylalanine into de novo myofibrillar protein were observed at 5 h (0.016 ± 0.002 and 0.014 ± 0.002 mole percent excess in PRO and PRONO3, respectively, P = 0.8). Dietary nitrate co-ingestion with protein does not modulate protein digestion and absorption kinetics, nor does it further increase postprandial muscle protein synthesis rates or the incorporation of dietary protein-derived amino acids into de novo myofibrillar protein in older, type 2 diabetes patients.
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Affiliation(s)
- Imre W K Kouw
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Naomi M Cermak
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Nicholas A Burd
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Tyler A Churchward-Venne
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Joan M Senden
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Annemarie P Gijsen
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Luc J C van Loon
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
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Oral nitrate and citrulline decrease blood pressure and increase vascular conductance in young adults: a potential therapy for heart failure. Eur J Appl Physiol 2016; 116:1651-61. [PMID: 27333912 PMCID: PMC4983290 DOI: 10.1007/s00421-016-3418-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 06/15/2016] [Indexed: 02/08/2023]
Abstract
Purpose Both inorganic nitrate and citrulline are known to alter the arginine–nitric oxide–nitrate system to increase the bioavailability of nitric oxide with potential benefits in the treatment of heart failure. However, their effects on cardiac electrical activity, vascular compliance and peripheral conductance are less well understood. This study examined the effect of nitrate and citrulline on cardiac electrical activity and blood flow. Methods Young adult subjects (n = 12) were recruited to investigate the effects of acute oral nitrate consumption (8 mg/kg) and chronic citrulline consumption (3 g/day) on cardiac electrical activity measured by ECG recording and blood pressure. Blood flow and vascular compliance were measured by IR-plethysmography at the thumb and the hallux. Results Nitrate (p < 0.05) and citrulline (p < 0.01) consumption both decreased diastolic blood pressure but had no effect on either pulse pressure or rate-pressure product (NS for both). Citrulline also decreased systolic pressure (p < 0.01). Nitrate and citrulline both decreased vascular compliance (p < 0.05 for both) prior to isometric grip exercise, but this was increased for nitrate following exercise (NS). Citrulline decreased R–R interval 9 % (p < 0.05) at rest and increased heart rate (p < 0.05) in addition to significantly decreasing pulse transit duration (6 %; p < 0.05). QRS duration was also decreased by 5 % for citrulline (p < 0.05) with the reduction in R–R interval. Conclusion Both nitrate and citrulline supplementation decreased vascular tone at rest but citrulline also altered sympathovagal balance to increase sympathetic tone. We suggest that both oral nitrate and citrulline may be suitable adjuvants for patients with heart failure to improve peripheral tissue oxygenation.
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Exceptional body composition changes attributed to collagen peptide supplementation and resistance training in older sarcopenic men. Br J Nutr 2016; 116:569-70. [DOI: 10.1017/s000711451600221x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Brook MS, Wilkinson DJ, Phillips BE, Perez-Schindler J, Philp A, Smith K, Atherton PJ. Skeletal muscle homeostasis and plasticity in youth and ageing: impact of nutrition and exercise. Acta Physiol (Oxf) 2016; 216:15-41. [PMID: 26010896 PMCID: PMC4843955 DOI: 10.1111/apha.12532] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 11/10/2014] [Accepted: 05/18/2015] [Indexed: 12/18/2022]
Abstract
Skeletal muscles comprise a substantial portion of whole body mass and are integral for locomotion and metabolic health. Increasing age is associated with declines in both muscle mass and function (e.g. strength‐related performance, power) with declines in muscle function quantitatively outweighing those in muscle volume. The mechanisms behind these declines are multi‐faceted involving both intrinsic age‐related metabolic dysregulation and environmental influences such as nutritional and physical activity. Ageing is associated with a degree of ‘anabolic resistance’ to these key environmental inputs, which likely accelerates the intrinsic processes driving ageing. On this basis, strategies to sensitize and/or promote anabolic responses to nutrition and physical activity are likely to be imperative in alleviating the progression and trajectory of sarcopenia. Both resistance‐ and aerobic‐type exercises are likely to confer functional and health benefits in older age, and a clutch of research suggests that enhancement of anabolic responsiveness to exercise and/or nutrition may be achieved by optimizing modifications of muscle‐loading paradigms (workload, volume, blood flow restriction) or nutritional support (e.g. essential amino acid/leucine) patterns. Nonetheless, more work is needed in which a more holistic view in ageing studies is taken into account. This should include improved characterization of older study recruits, that is physical activity/nutritional behaviours, to limit confounding variables influencing whether findings are attributable to age, or other environmental influences. Nonetheless, on balance, ageing is associated with declines in muscle mass and function and a partially related decline in aerobic capacity. There is also good evidence that metabolic flexibility is impaired in older age.
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Affiliation(s)
- M. S. Brook
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, Clinical Metabolic and Molecular Physiology; University of Nottingham; Royal Derby Hospital Centre; Derby UK
| | - D. J. Wilkinson
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, Clinical Metabolic and Molecular Physiology; University of Nottingham; Royal Derby Hospital Centre; Derby UK
| | - B. E. Phillips
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, Clinical Metabolic and Molecular Physiology; University of Nottingham; Royal Derby Hospital Centre; Derby UK
| | - J. Perez-Schindler
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences; University of Birmingham; Birmingham UK
| | - A. Philp
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences; University of Birmingham; Birmingham UK
| | - K. Smith
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, Clinical Metabolic and Molecular Physiology; University of Nottingham; Royal Derby Hospital Centre; Derby UK
| | - P. J. Atherton
- MRC-ARUK Centre of Excellence for Musculoskeletal Ageing Research, Clinical Metabolic and Molecular Physiology; University of Nottingham; Royal Derby Hospital Centre; Derby UK
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Kim IY, Schutzler SE, Schrader A, Spencer HJ, Azhar G, Deutz NEP, Wolfe RR. Acute ingestion of citrulline stimulates nitric oxide synthesis but does not increase blood flow in healthy young and older adults with heart failure. Am J Physiol Endocrinol Metab 2015; 309:E915-24. [PMID: 26442881 PMCID: PMC4669336 DOI: 10.1152/ajpendo.00339.2015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 09/29/2015] [Indexed: 11/22/2022]
Abstract
To determine if age-associated vascular dysfunction in older adults with heart failure (HF) is due to insufficient synthesis of nitric oxide (NO), we performed two separate studies: 1) a kinetic study with a stable isotope tracer method to determine in vivo kinetics of NO metabolism, and 2) a vascular function study using a plethysmography method to determine reactive hyperemic forearm blood flow (RH-FBF) in older and young adults in the fasted state and in response to citrulline ingestion. In the fasted state, NO synthesis (per kg body wt) was ∼ 50% lower in older vs. young adults and was related to a decreased rate of appearance of the NO precursor arginine. Citrulline ingestion (3 g) stimulated de novo arginine synthesis in both older [6.88 ± 0.83 to 35.40 ± 4.90 μmol · kg body wt(-1) · h(-1)] and to a greater extent in young adults (12.02 ± 1.01 to 66.26 ± 4.79 μmol · kg body wt(-1) · h(-1)). NO synthesis rate increased correspondingly in older (0.17 ± 0.01 to 2.12 ± 0.36 μmol · kg body wt(-1) · h(-1)) and to a greater extent in young adults (0.36 ± 0.04 to 3.57 ± 0.47 μmol · kg body wt(-1) · h(-1)). Consistent with the kinetic data, RH-FBF in the fasted state was ∼ 40% reduced in older vs. young adults. However, citrulline ingestion (10 g) failed to increase RH-FBF in either older or young adults. In conclusion, citrulline ingestion improved impaired NO synthesis in older HF adults but not RH-FBF, suggesting that factors other than NO synthesis play a role in the impaired RH-FBF in older HF adults, and/or it may require a longer duration of supplementation to be effective in improving RH-FBF.
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Affiliation(s)
- Il-Young Kim
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, Arkansas,
| | - Scott E Schutzler
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Amy Schrader
- College of Medicine Biostatistics, University of Arkansas for Medical Sciences, Little Rock, Arkansas; and
| | - Horace J Spencer
- College of Medicine Biostatistics, University of Arkansas for Medical Sciences, Little Rock, Arkansas; and
| | - Gohar Azhar
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Nicolaas E P Deutz
- Center for Translational Research in Aging and Longevity, Department of Health and Kinesiology, Texas A&M University, College Station, Texas
| | - Robert R Wolfe
- Department of Geriatrics, Center for Translational Research in Aging and Longevity, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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Ham DJ, Gleeson BG, Chee A, Baum DM, Caldow MK, Lynch GS, Koopman R. L-Citrulline Protects Skeletal Muscle Cells from Cachectic Stimuli through an iNOS-Dependent Mechanism. PLoS One 2015; 10:e0141572. [PMID: 26513461 PMCID: PMC4625972 DOI: 10.1371/journal.pone.0141572] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 10/09/2015] [Indexed: 12/31/2022] Open
Abstract
Dietary L-citrulline is thought to modulate muscle protein turnover by increasing L-arginine availability. To date, the direct effects of increased L-citrulline concentrations in muscle have been completely neglected. Therefore, we determined the role of L-citrulline in regulating cell size during catabolic conditions by depriving mature C2C12 myotubes of growth factors (serum free; SF) or growth factors and nutrients (HEPES buffered saline; HBS). Cells were treated with L-citrulline or equimolar concentrations of L-arginine (positive control) or L-alanine (negative control) and changes in cell size and protein turnover were assessed. In myotubes incubated in HBS or SF media, L-citrulline improved rates of protein synthesis (HBS: +63%, SF: +37%) and myotube diameter (HBS: +18%, SF: +29%). L-citrulline treatment substantially increased iNOS mRNA expression (SF: 350%, HBS: 750%). The general NOS inhibitor L-NAME and the iNOS specific inhibitor aminoguanidine prevented these effects in both models. Depriving myotubes in SF media of L-arginine or L-leucine, exacerbated wasting which was not attenuated by L-citrulline. The increased iNOS mRNA expression was temporally associated with increases in mRNA of the endogenous antioxidants SOD1, SOD3 and catalase. Furthermore, L-citrulline prevented inflammation (LPS) and oxidative stress (H2O2) induced muscle cell wasting. In conclusion, we demonstrate a novel direct protective effect of L-citrulline on skeletal muscle cell size independent of L-arginine that is mediated through induction of the inducible NOS (iNOS) isoform. This discovery of a nutritional modulator of iNOS mRNA expression in skeletal muscle cells could have substantial implications for the treatment of muscle wasting conditions.
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Affiliation(s)
- Daniel J. Ham
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
| | - Benjamin G. Gleeson
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
| | - Annabel Chee
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
| | - Dale M. Baum
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
| | - Marissa K. Caldow
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
| | - Gordon S. Lynch
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
| | - René Koopman
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
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Consumption of Milk Protein or Whey Protein Results in a Similar Increase in Muscle Protein Synthesis in Middle Aged Men. Nutrients 2015; 7:8685-99. [PMID: 26506377 PMCID: PMC4632440 DOI: 10.3390/nu7105420] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 09/23/2015] [Accepted: 09/29/2015] [Indexed: 02/07/2023] Open
Abstract
The differential ability of various milk protein fractions to stimulate muscle protein synthesis (MPS) has been previously described, with whey protein generally considered to be superior to other fractions. However, the relative ability of a whole milk protein to stimulate MPS has not been compared to whey. Sixteen healthy middle-aged males ingested either 20 g of milk protein (n = 8) or whey protein (n = 8) while undergoing a primed constant infusion of ring 13C6 phenylalanine. Muscle biopsies were obtained 120 min prior to consumption of the protein and 90 and 210 min afterwards. Resting myofibrillar fractional synthetic rates (FSR) were 0.019% ± 0.009% and 0.021% ± 0.018% h−1 in the milk and whey groups respectively. For the first 90 min after protein ingestion the FSR increased (p < 0.001) to 0.057% ± 0.018% and 0.052% ± 0.024% h−1 in the milk and whey groups respectively with no difference between groups (p = 0.810). FSR returned to baseline in both groups between 90 and 210 min after protein ingestion. Despite evidence of increased rate of digestion and leucine availability following the ingestion of whey protein, there was similar activation of MPS in middle-aged men with either 20 g of milk protein or whey protein.
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Devries MC, Breen L, Von Allmen M, MacDonald MJ, Moore DR, Offord EA, Horcajada MN, Breuillé D, Phillips SM. Low-load resistance training during step-reduction attenuates declines in muscle mass and strength and enhances anabolic sensitivity in older men. Physiol Rep 2015; 3:3/8/e12493. [PMID: 26265753 PMCID: PMC4562579 DOI: 10.14814/phy2.12493] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Step-reduction (SR) in older adults results in muscle atrophy and an attenuated rise in postprandial muscle protein synthesis (MPS): anabolic resistance. Knowing that resistance exercise (RT) can enhance MPS, we examined whether RT could enhance MPS following 2 weeks of SR. In addition, as we postulated that SR may impair feeding-induced vasodilation limiting nutrient delivery to muscle, we also examined whether citrulline (CIT), as an arginine and nitric oxide precursor, could attenuate muscle anabolic resistance accompanying SR. We used a unilateral leg model to compare older subjects’ who had undergone SR to a loaded condition of SR plus RT (SR + RT). Thirty older men (70 ± 1 years) underwent 14 days of SR (<1500 steps/day) with supplementation of either 5 g/day CIT or glycine placebo. Throughout SR, subjects performed unilateral low-load RT thrice weekly. We assessed muscle protein synthesis in the postabsorptive and postprandial state (20 g whey isolate plus 15 g glycine or as micellar-whey with 5 g CIT or 15 g glycine, n = 10/group). As MPS was similar after ingestion of either whey isolate, micellar-whey, or micellar-whey + CIT data related to different dietary groups were collapsed to compare SR and SR + RT legs. Subjects’ daily steps were reduced by 80 ± 2% during SR (P < 0.001) compared with baseline. Leg fat-free mass decreased with SR (−124 ± 61 g) and increased in the SR + RT (+126 ± 68 g; P = 0.003). Myofibrillar FSR was lower (P < 0.0001) in the SR as compared with the SR + RT leg in the postabsorptive (0.026 ± 0.001%/h vs. 0.045 ± 0.001%/h) and postprandial states (0.055 ± 0.002%/h vs. 0.115 ± 0.003%/h). We conclude that low-load RT, but not supplementation with CIT, can attenuate the deleterious effects of SR in aging muscle.
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Affiliation(s)
| | - Leigh Breen
- Department of Kinesiology, McMaster University, Hamilton, Canada School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Mark Von Allmen
- Department of Kinesiology, McMaster University, Hamilton, Canada
| | | | - Daniel R Moore
- Faculty of Kinesiology & Physical Education, University of Toronto, Toronto, Canada
| | | | | | - Denis Breuillé
- Nestlé Research Center, Nestec Ltd, Lausanne, Switzerland
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Ham DJ, Kennedy TL, Caldow MK, Chee A, Lynch GS, Koopman R. Citrulline does not prevent skeletal muscle wasting or weakness in limb-casted mice. J Nutr 2015; 145:900-6. [PMID: 25740910 DOI: 10.3945/jn.114.203737] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 01/20/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Increasing arginine (Arg) availability reduces atrophy in cultured skeletal muscle cells. Supplementation with its metabolic precursor citrulline (Cit) is more effective at improving skeletal muscle Arg concentrations. OBJECTIVE We tested the hypothesis that Cit supplementation would attenuate skeletal muscle atrophy and loss of function during hindlimb immobilization in mice. METHODS Male C57BL/6JArc mice underwent 14 d of unilateral hindlimb immobilization/plaster casting and were supplemented with ~0.81 g Cit · kg⁻¹ · d⁻¹ (CIT group) or Ala (ALA group) mixed into their food. The uncasted contralateral limb (internal control) and an uncasted group (CON) served as controls. Muscle atrophy was evaluated with mass, fiber area, and in situ muscle function. RESULTS Tibialis anterior (TA) muscle mass [ALA: 37.6 ± 0.92 mg; CIT: 38.3 ± 1.25 mg] and peak tetanic force (ALA: 1150 ± 38.5 mN; CIT: 1150 ± 52.0 mN) were lower (P < 0.001) in the ALA (53.9 ± 0.42 mg) and CIT (1760 ± 28.5 mN) groups than in the CON group. No difference was found between ALA and CIT groups for TA mass, fiber area, or peak force. The mRNA expression of the nitric oxide synthase 2, inducible (Nos2; ~15-fold) and B-cell chronic lymphoid leukemia/lymphoma 2/adenovirus E1B 19 kDa interacting protein 3 (Bnip3; ~17-fold) genes and the ratio of microtubule-associated protein light chain 3BII to 3BI (LC3BII:LC3BI) (50.5% ± 17.7%) were higher (P < 0.05) in the ALA group than in the CON group, suggesting increased autophagy. In the CIT group, Bnip3 mRNA was lower (-70%; P < 0.05) and Nos2 mRNA tended to be lower (-45%; P = 0.05) than in the ALA group, whereas LC3BII:LC3BI was not different from the CON group. CONCLUSIONS Cit treatment of male mice did not affect therapeutically relevant outcome measures such as skeletal muscle mass and peak muscle force after 14 d of hindlimb immobilization.
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Affiliation(s)
- Daniel J Ham
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Australia
| | - Tahnee L Kennedy
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Australia
| | - Marissa K Caldow
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Australia
| | - Annabel Chee
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Australia
| | - Gordon S Lynch
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Australia
| | - René Koopman
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Parkville, Australia
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Murphy CH, Churchward-Venne TA, Mitchell CJ, Kolar NM, Kassis A, Karagounis LG, Burke LM, Hawley JA, Phillips SM. Hypoenergetic diet-induced reductions in myofibrillar protein synthesis are restored with resistance training and balanced daily protein ingestion in older men. Am J Physiol Endocrinol Metab 2015; 308:E734-43. [PMID: 25738784 PMCID: PMC4420900 DOI: 10.1152/ajpendo.00550.2014] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 02/23/2015] [Indexed: 01/22/2023]
Abstract
Strategies to enhance weight loss with a high fat-to-lean ratio in overweight/obese older adults are important since lean loss could exacerbate sarcopenia. We examined how dietary protein distribution affected muscle protein synthesis during energy balance (EB), energy restriction (ER), and energy restriction plus resistance training (ER + RT). A 4-wk ER diet was provided to overweight/obese older men (66 ± 4 yr, 31 ± 5 kg/m(2)) who were randomized to either a balanced (BAL: 25% daily protein/meal × 4) or skewed (SKEW: 7:17:72:4% daily protein/meal; n = 10/group) pattern. Myofibrillar and sarcoplasmic protein fractional synthetic rates (FSR) were measured during a 13-h primed continuous infusion of l-[ring-(13)C6]phenylalanine with BAL and SKEW pattern of protein intake in EB, after 2 wk ER, and after 2 wk ER + RT. Fed-state myofibrillar FSR was lower in ER than EB in both groups (P < 0.001), but was greater in BAL than SKEW (P = 0.014). In ER + RT, fed-state myofibrillar FSR increased above ER in both groups and in BAL was not different from EB (P = 0.903). In SKEW myofibrillar FSR remained lower than EB (P = 0.002) and lower than BAL (P = 0.006). Fed-state sarcoplasmic protein FSR was reduced similarly in ER and ER + RT compared with EB (P < 0.01) in both groups. During ER in overweight/obese older men a BAL consumption of protein stimulated the synthesis of muscle contractile proteins more effectively than traditional, SKEW distribution. Combining RT with a BAL protein distribution "rescued" the lower rates of myofibrillar protein synthesis during moderate ER.
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Affiliation(s)
- Caoileann H Murphy
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | | | - Cameron J Mitchell
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Nathan M Kolar
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Amira Kassis
- Nestlé Research Center, Nestec, Lausanne, Switzerland
| | | | - Louise M Burke
- Department of Sports Nutrition, Australian Institute of Sport, Canberra, Australia
| | - John A Hawley
- Exercise and Nutrition Research Group, School of Exercise Science, Australian Catholic University, Fitzroy, Victoria, Australia; Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, United Kingdom; and
| | - Stuart M Phillips
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada;
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49
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Muscle protein turnover in the elderly and its potential contribution to the development of sarcopenia. Proc Nutr Soc 2015; 74:387-96. [PMID: 25826683 DOI: 10.1017/s0029665115000130] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The underlying aetiology of sarcopenia appears multifaceted and not yet fully defined, but ultimately involves the gradual loss of muscle protein content over time. The present evidence suggests that the loss of lean tissue in the elderly is exacerbated by low dietary protein intake. Moreover, acute stable-isotope-based methodologies have demonstrated that the muscle anabolic response to a given amount of protein may decline with age, a phenomenon that has been termed anabolic resistance. Although the mechanism responsible for the inability of muscle to mount a satisfactory anabolic response to protein provision with increasing age is presently unknown, it does not appear due to impaired digestion or absorption of dietary protein. Rather, the issue could reside with any combination of: a diminished delivery of amino acids to peripheral tissues, impaired uptake of amino acids into muscle cells, or an inability of amino acids to elicit intracellular events pivotal for anabolism to occur. Despite the presence of anabolic resistance to dietary protein, present evidence suggests that protein supplementation may be able to overcome these issues, particularly when combined with resistance exercise programmes. As such, protein supplementation may prove to be an effective approach to delay the loss of muscle mass with age and has led to calls for the recommended daily intake of protein to be increased for the elderly population.
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50
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Bell KE, Séguin C, Parise G, Baker SK, Phillips SM. Day-to-Day Changes in Muscle Protein Synthesis in Recovery From Resistance, Aerobic, and High-Intensity Interval Exercise in Older Men. J Gerontol A Biol Sci Med Sci 2015; 70:1024-9. [DOI: 10.1093/gerona/glu313] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Accepted: 12/17/2014] [Indexed: 12/14/2022] Open
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