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Pedersen MGB, Rittig N, Bangshaab M, Berg-Hansen K, Gopalasingam N, Gormsen LC, Søndergaard E, Møller N. Effects of exogenous lactate on lipid, protein, and glucose metabolism-a randomized crossover trial in healthy males. Am J Physiol Endocrinol Metab 2024; 326:E443-E453. [PMID: 38324259 PMCID: PMC11193511 DOI: 10.1152/ajpendo.00301.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 01/18/2024] [Accepted: 02/01/2024] [Indexed: 02/08/2024]
Abstract
Lactate may inhibit lipolysis and thus enhance insulin sensitivity, but there is a lack of metabolic human studies. This study aimed to determine how hyperlactatemia affects lipolysis, glucose- and protein metabolism, and insulin sensitivity in healthy men. In a single-blind, randomized, crossover design, eight healthy men were studied after an overnight fast on two occasions: 1) during a sodium-lactate infusion (LAC) and 2) during a sodium-matched NaCl infusion (CTR). Both days consisted of a 3-h postabsorptive period followed by a 3-h hyperinsulinemic-euglycemic clamp (HEC). Lipolysis rate, endogenous glucose production (EGP), and delta glucose rate of disappearance (ΔRdglu) were evaluated using [9,10-3H]palmitate and [3-3H]glucose tracers. In addition, whole body- and forearm protein metabolism was assessed using [15N]phenylalanine, [2H4]tyrosine, [15N]tyrosine, and [13C]urea tracers. In the postabsorptive period, plasma lactate increased to 2.7 ± 0.5 mmol/L during LAC vs. 0.6 ± 0.3 mmol/L during CTR (P < 0.001). In the postabsorptive period, palmitate flux was 30% lower during LAC compared with CTR (84 ± 32 µmol/min vs. 120 ± 35 µmol/min, P = 0.003). During the HEC, palmitate flux was suppressed similarly during both interventions (P = 0.7). EGP, ΔRdglu, and M value were similar during LAC and CTR. During HEC, LAC increased whole body phenylalanine flux (P = 0.02) and protein synthesis (P = 0.03) compared with CTR; LAC did not affect forearm protein metabolism compared with CTR. Lactate infusion inhibited lipolysis by 30% under postabsorptive conditions but did not affect glucose metabolism or improve insulin sensitivity. In addition, whole body phenylalanine flux was increased. Clinical trial registrations: NCT04710875.NEW & NOTEWORTHY Lactate is a decisive intermediary metabolite, serving as an energy substrate and a signaling molecule. The present study examines the effects of lactate on substrate metabolism and insulin sensitivity in healthy males. Hyperlactatemia reduces lipolysis by 30% without affecting insulin sensitivity and glucose metabolism. In addition, hyperlactatemia increases whole body amino acid turnover rate.
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Affiliation(s)
- Mette G B Pedersen
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
- Medical Research Laboratory, Aarhus University, Aarhus, Denmark
| | - Nikolaj Rittig
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
- Medical Research Laboratory, Aarhus University, Aarhus, Denmark
| | - Maj Bangshaab
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
- Medical Research Laboratory, Aarhus University, Aarhus, Denmark
| | | | | | - Lars C Gormsen
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus, Denmark
| | - Esben Søndergaard
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Niels Møller
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
- Medical Research Laboratory, Aarhus University, Aarhus, Denmark
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Edman S, Horwath O, Van der Stede T, Blackwood SJ, Moberg I, Strömlind H, Nordström F, Ekblom M, Katz A, Apró W, Moberg M. Pro-Brain-Derived Neurotrophic Factor (BDNF), but Not Mature BDNF, Is Expressed in Human Skeletal Muscle: Implications for Exercise-Induced Neuroplasticity. FUNCTION 2024; 5:zqae005. [PMID: 38706964 PMCID: PMC11065112 DOI: 10.1093/function/zqae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/15/2023] [Accepted: 01/24/2024] [Indexed: 05/07/2024] Open
Abstract
Exercise promotes brain plasticity partly by stimulating increases in mature brain-derived neurotrophic factor (mBDNF), but the role of the pro-BDNF isoform in the regulation of BDNF metabolism in humans is unknown. We quantified the expression of pro-BDNF and mBDNF in human skeletal muscle and plasma at rest, after acute exercise (+/- lactate infusion), and after fasting. Pro-BDNF and mBDNF were analyzed with immunoblotting, enzyme-linked immunosorbent assay, immunohistochemistry, and quantitative polymerase chain reaction. Pro-BDNF was consistently and clearly detected in skeletal muscle (40-250 pg mg-1 dry muscle), whereas mBDNF was not. All methods showed a 4-fold greater pro-BDNF expression in type I muscle fibers compared to type II fibers. Exercise resulted in elevated plasma levels of mBDNF (55%) and pro-BDNF (20%), as well as muscle levels of pro-BDNF (∼10%, all P < 0.05). Lactate infusion during exercise induced a significantly greater increase in plasma mBDNF (115%, P < 0.05) compared to control (saline infusion), with no effect on pro-BDNF levels in plasma or muscle. A 3-day fast resulted in a small increase in plasma pro-BDNF (∼10%, P < 0.05), with no effect on mBDNF. Pro-BDNF is highly expressed in human skeletal muscle, particularly in type I fibers, and is increased after exercise. While exercising with higher lactate augmented levels of plasma mBDNF, exercise-mediated increases in circulating mBDNF likely derive partly from release and cleavage of pro-BDNF from skeletal muscle, and partly from neural and other tissues. These findings have implications for preclinical and clinical work related to a wide range of neurological disorders such as Alzheimer's, clinical depression, and amyotrophic lateral sclerosis.
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Affiliation(s)
- Sebastian Edman
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
- Department of Women’s and Children’s Health, Karolinska Institute, Stockholm 171 77, Sweden
| | - Oscar Horwath
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
| | - Thibaux Van der Stede
- Department of Movement and Sport Sciences, Ghent University, Ghent 9000, Belgium
- The August Krogh Section for Human Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen 1172, Denmark
| | - Sarah Joan Blackwood
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
| | - Isabel Moberg
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
| | - Henrik Strömlind
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
| | - Fabian Nordström
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
| | - Maria Ekblom
- Department of Physical Activity and Health, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
- Department of Neuroscience, Karolinska Institute, Stockholm 171 77, Sweden
| | - Abram Katz
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
| | - William Apró
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
- Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm 171 77, Sweden
| | - Marcus Moberg
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm 171 77, Sweden
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3
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Mattingly ML, Ruple BA, Sexton CL, Godwin JS, McIntosh MC, Smith MA, Plotkin DL, Michel JM, Anglin DA, Kontos NJ, Fei S, Phillips SM, Mobley CB, Vechetti I, Vann CG, Roberts MD. Resistance training in humans and mechanical overload in rodents do not elevate muscle protein lactylation. Front Physiol 2023; 14:1281702. [PMID: 37841321 PMCID: PMC10569119 DOI: 10.3389/fphys.2023.1281702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 09/20/2023] [Indexed: 10/17/2023] Open
Abstract
Although several reports have hypothesized that exercise may increase skeletal muscle protein lactylation, empirical evidence in humans is lacking. Thus, we adopted a multi-faceted approach to examine if acute and subchronic resistance training (RT) altered skeletal muscle protein lactylation levels. In mice, we also sought to examine if surgical ablation-induced plantaris hypertrophy coincided with increases in muscle protein lactylation. To examine acute responses, participants' blood lactate concentrations were assessed before, during, and after eight sets of an exhaustive lower body RT bout (n = 10 trained college-aged men). Vastus lateralis biopsies were also taken before, 3-h post, and 6-h post-exercise to assess muscle protein lactylation. To identify training responses, another cohort of trained college-aged men (n = 14) partook in 6 weeks of lower-body RT (3x/week) and biopsies were obtained before and following the intervention. Five-month-old C57BL/6 mice were subjected to 10 days of plantaris overload (OV, n = 8) or served as age-matched sham surgery controls (Sham, n = 8). Although acute resistance training significantly increased blood lactate responses ∼7.2-fold (p < 0.001), cytoplasmic and nuclear protein lactylation levels were not significantly altered at the post-exercise time points, and no putative lactylation-dependent mRNA was altered following exercise. Six weeks of RT did not alter cytoplasmic protein lactylation (p = 0.800) despite significantly increasing VL muscle size (+3.5%, p = 0.037), and again, no putative lactylation-dependent mRNA was significantly affected by training. Plantaris muscles were larger in OV versus Sham mice (+43.7%, p < 0.001). However, cytoplasmic protein lactylation was similar between groups (p = 0.369), and nuclear protein lactylation was significantly lower in OV versus Sham mice (p < 0.001). The current null findings, along with other recent null findings in the literature, challenge the thesis that lactate has an appreciable role in promoting skeletal muscle hypertrophy.
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Affiliation(s)
| | - Bradley A. Ruple
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | - Casey L. Sexton
- Department of Physiology and Aging, University of Florida, Gainesville, FL, United States
| | - Joshua S. Godwin
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | | | - Morgan A. Smith
- Department of Genetics, Standford University, Stanford, CA, United States
| | | | - J. Max Michel
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | - Derick A. Anglin
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | | | - Shengyi Fei
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | | | - C. Brooks Mobley
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | - Ivan Vechetti
- Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Christopher G. Vann
- Duke Molecular Physiology Institute, Duke University School of Medicine, Duke University, Durham, NC, United States
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Horwath O, Nordström F, von Walden F, Apró W, Moberg M. Acute hypoxia attenuates resistance exercise-induced ribosome signaling but does not impact satellite cell pool expansion in human skeletal muscle. FASEB J 2023; 37:e22811. [PMID: 36786723 DOI: 10.1096/fj.202202065rr] [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: 12/09/2022] [Revised: 01/25/2023] [Accepted: 01/27/2023] [Indexed: 02/15/2023]
Abstract
Cumulative evidence supports the hypothesis that hypoxia acts as a regulator of muscle mass. However, the underlying molecular mechanisms remain incompletely understood, particularly in human muscle. Here we examined the effect of hypoxia on signaling pathways related to ribosome biogenesis and myogenic activity following an acute bout of resistance exercise. We also investigated whether hypoxia influenced the satellite cell response to resistance exercise. Employing a randomized, crossover design, eight men performed resistance exercise in normoxia (FiO2 21%) or normobaric hypoxia (FiO2 12%). Muscle biopsies were collected in a time-course manner (before, 0, 90, 180 min and 24 h after exercise) and were analyzed with respect to cell signaling, gene expression and satellite cell content using immunoblotting, RT-qPCR and immunofluorescence, respectively. In normoxia, resistance exercise increased the phosphorylation of RPS6, TIF-1A and UBF above resting levels. Hypoxia reduced the phosphorylation of these targets by ~37%, ~43% and ~ 67% throughout the recovery period, respectively (p < .05 vs. normoxia). Resistance exercise also increased 45 S pre-rRNA expression and mRNA expression of c-Myc, Pol I and TAF-1A above resting levels, but no differences were observed between conditions. Similarly, resistance exercise increased mRNA expression of myogenic regulatory factors throughout the recovery period and Pax7+ cells were elevated 24 h following exercise in mixed and type II muscle fibers, with no differences observed between normoxia and hypoxia. In conclusion, acute hypoxia attenuates ribosome signaling, but does not impact satellite cell pool expansion and myogenic gene expression following a bout of resistance exercise in human skeletal muscle.
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Affiliation(s)
- Oscar Horwath
- Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Fabian Nordström
- Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Ferdinand von Walden
- Division of Pediatric Neurology, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - William Apró
- Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm, Sweden.,Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Solna, Sweden
| | - Marcus Moberg
- Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm, Sweden.,Department of Physiology and Pharmacology, Karolinska Institutet, Solna, Sweden
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5
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Nordström F, Liegnell R, Apró W, Blackwood SJ, Katz A, Moberg M. The lactate receptor GPR81 is predominantly expressed in type II human skeletal muscle fibers: potential for lactate autocrine signaling. Am J Physiol Cell Physiol 2023; 324:C477-C487. [PMID: 36622074 DOI: 10.1152/ajpcell.00443.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Gi-coupled protein receptor 81 (GPR81) was first identified in adipocytes as a receptor for l-lactate, which upon binding inhibits cyclicAMP (cAMP)-protein kinase (PKA)-cAMP-response element binding (CREB) signaling. Moreover, incubation of myotubes with lactate augments expression of GPR81 and genes and proteins involved in lactate- and energy metabolism. However, characterization of GPR81 expression and investigation of related signaling in human skeletal muscle under conditions of elevated circulating lactate levels are lacking. Muscle biopsies were obtained from healthy men and women at rest, after leg extension exercise, with or without venous infusion of sodium lactate, and 90 and 180 min after exercise (8 men and 8 women). Analyses included protein and mRNA levels of GPR81, as well as GPR81-dependent signaling molecules. GPR81 expression was 2.5-fold higher in type II glycolytic compared with type I oxidative muscle fibers, and the expression was inversely related to the percentage of type I muscle fibers. Muscle from women expressed about 25% more GPR81 protein than from men. Global PKA activity increased by 5%-8% after exercise, with no differences between trials. CREBS133 phosphorylation was reduced by 30% after exercise and remained repressed during the entire trials, with no influence of the lactate infusion. The mRNA expression of vascular endothelial growth factor (VEGF) and peroxisome-proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) were increased by 2.5-6-fold during recovery, and that of lactate dehydrogenase reduced by 15% with no differences between trials for any gene at any time point. The high expression of GPR81-protein in type II fibers suggests that lactate functions as an autocrine signaling molecule in muscle; however, lactate does not appear to regulate CREB signaling during exercise.
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Affiliation(s)
- Fabian Nordström
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, https://ror.org/046hach49Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Rasmus Liegnell
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, https://ror.org/046hach49Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - William Apró
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, https://ror.org/046hach49Swedish School of Sport and Health Sciences, Stockholm, Sweden.,Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm, Sweden
| | - Sarah J Blackwood
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, https://ror.org/046hach49Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Abram Katz
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, https://ror.org/046hach49Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Marcus Moberg
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, https://ror.org/046hach49Swedish School of Sport and Health Sciences, Stockholm, Sweden.,Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
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Lawson D, Vann C, Schoenfeld BJ, Haun C. Beyond Mechanical Tension: A Review of Resistance Exercise-Induced Lactate Responses & Muscle Hypertrophy. J Funct Morphol Kinesiol 2022; 7:jfmk7040081. [PMID: 36278742 PMCID: PMC9590033 DOI: 10.3390/jfmk7040081] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 11/07/2022] Open
Abstract
The present review aims to explore and discuss recent research relating to the lactate response to resistance training and the potential mechanisms by which lactate may contribute to skeletal muscle hypertrophy or help to prevent muscle atrophy. First, we will discuss foundational information pertaining to lactate including metabolism, measurement, shuttling, and potential (although seemingly elusive) mechanisms for hypertrophy. We will then provide a brief analysis of resistance training protocols and the associated lactate response. Lastly, we will discuss potential shortcomings, resistance training considerations, and future research directions regarding lactate's role as a potential anabolic agent for skeletal muscle hypertrophy.
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Affiliation(s)
- Daniel Lawson
- School of Kinesiology, Applied Health and Recreation, Oklahoma State University, Stillwater, OK 74078, USA
- Correspondence:
| | - Christopher Vann
- Duke Molecular Physiology Institute, Duke University School of Medicine, Duke University, Durham, NC 27701, USA
| | - Brad J. Schoenfeld
- Department of Exercise Science and Recreation, Lehman College of CUNY, Bronx, NY 10468, USA
| | - Cody Haun
- Fitomics, LLC, Alabaster, AL 35007, USA
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7
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Shirai T, Kitaoka Y, Uemichi K, Tokinoya K, Takeda K, Takemasa T. Effects of lactate administration on hypertrophy and mTOR signaling activation in mouse skeletal muscle. Physiol Rep 2022; 10:e15436. [PMID: 35993446 PMCID: PMC9393907 DOI: 10.14814/phy2.15436] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/01/2022] [Accepted: 05/16/2022] [Indexed: 04/12/2023] Open
Abstract
Lactate is a metabolic product of glycolysis and has recently been shown to act as a signaling molecule that induces adaptations in oxidative metabolism. In this study, we investigated whether lactate administration enhanced muscle hypertrophy and protein synthesis responses during resistance exercise in animal models. We used male ICR mice (7-8 weeks old) were used for chronic (mechanical overload induced by synergist ablation: [OL]) and acute (high-intensity muscle contraction by electrical stimulation: [ES]) resistance exercise models. The animals were intraperitoneally administrated a single dose of sodium lactate (1 g/kg of body weight) in the ES study, and once a day for 14 consecutive days in the OL study. Two weeks of mechanical overload increased plantaris muscle wet weight (main effect of OL: p < 0.05) and fiber cross-sectional area (main effect of OL: p < 0.05), but those were not affected by lactate administration. Following the acute resistance exercise by ES, protein synthesis and phosphorylation of p70 S6 kinase and ribosomal protein S6, which are downstream molecules in the anabolic signaling cascade, were increased (main effect of ES: p < 0.05), but lactate administration had no effect. This study demonstrated that exogenous lactate administration has little effect on the muscle hypertrophic response during resistance exercise using acute ES and chronic OL models. Our results do not support the hypothesis that elevated blood lactate concentration induces protein synthesis responses in skeletal muscle.
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Affiliation(s)
- Takanaga Shirai
- Faculty of Health and Sport SciencesUniversity of TsukubaTsukubaIbarakiJapan
- Research Fellow of Japan Society for Promotion ScienceChiyoda‐kuTokyoJapan
| | - Yu Kitaoka
- Department of Human SciencesKanagawa UniversityYokohama‐shiKanagawaJapan
| | - Kazuki Uemichi
- Graduate School of Comprehensive Human SciencesUniversity of TsukubaTsukubaIbarakiJapan
| | - Katsuyuki Tokinoya
- Research Fellow of Japan Society for Promotion ScienceChiyoda‐kuTokyoJapan
- Division of Clinical Medicine, Faculty of MedicineUniversity of TsukubaTsukubaIbarakiJapan
- Department of Health Promotion SciencesGraduate School of Human Health SciencesTokyo Metropolitan UniversityHachiojiTokyoJapan
| | - Kohei Takeda
- School of Political Science and EconomicsMeiji UniversitySuginami‐kuTokyoJapan
| | - Tohru Takemasa
- Faculty of Health and Sport SciencesUniversity of TsukubaTsukubaIbarakiJapan
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8
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Moberg M, Apró W, Horwath O, Hall G, Blackwood SJ, Katz A. Acute normobaric hypoxia blunts contraction-mediated mTORC1- and JNK-signaling in human skeletal muscle. Acta Physiol (Oxf) 2022; 234:e13771. [PMID: 34984845 PMCID: PMC9285439 DOI: 10.1111/apha.13771] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 09/28/2021] [Accepted: 01/01/2022] [Indexed: 12/26/2022]
Abstract
Aim Hypoxia has been shown to reduce resistance exercise‐induced stimulation of protein synthesis and long‐term gains in muscle mass. However, the mechanism whereby hypoxia exerts its effect is not clear. Here, we examine the effect of acute hypoxia on the activity of several signalling pathways involved in the regulation of muscle growth following a bout of resistance exercise. Methods Eight men performed two sessions of leg resistance exercise in normoxia or hypoxia (12% O2) in a randomized crossover fashion. Muscle biopsies were obtained at rest and 0, 90,180 minutes after exercise. Muscle analyses included levels of signalling proteins and metabolites associated with energy turnover. Results Exercise during normoxia induced a 5‐10‐fold increase of S6K1Thr389 phosphorylation throughout the recovery period, but hypoxia blunted the increases by ~50%. Phosphorylation of JNKThr183/Tyr185 and the JNK target SMAD2Ser245/250/255 was increased by 30‐ to 40‐fold immediately after the exercise in normoxia, but hypoxia blocked almost 70% of the activation. Throughout recovery, phosphorylation of JNK and SMAD2 remained elevated following the exercise in normoxia, but the effect of hypoxia was lost at 90‐180 minutes post‐exercise. Hypoxia had no effect on exercise‐induced Hippo or autophagy signalling and ubiquitin‐proteasome related protein levels. Nor did hypoxia alter the changes induced by exercise in high‐energy phosphates, glucose 6‐P, lactate or phosphorylation of AMPK or ACC. Conclusion We conclude that acute severe hypoxia inhibits resistance exercise‐induced mTORC1‐ and JNK signalling in human skeletal muscle, effects that do not appear to be mediated by changes in the degree of metabolic stress in the muscle.
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Affiliation(s)
- Marcus Moberg
- Åstrand Laboratory Department of Physiology, Nutrition and Biomechanics Swedish School of Sport and Health Sciences Stockholm Sweden
- Department of Physiology and Pharmacology Karolinska Institute Stockholm Sweden
| | - William Apró
- Åstrand Laboratory Department of Physiology, Nutrition and Biomechanics Swedish School of Sport and Health Sciences Stockholm Sweden
- Department of Clinical Science, Intervention and Technology Karolinska Institute Stockholm Sweden
| | - Oscar Horwath
- Åstrand Laboratory Department of Physiology, Nutrition and Biomechanics Swedish School of Sport and Health Sciences Stockholm Sweden
| | - Gerrit Hall
- Department of Biomedical Sciences Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
- Clinical Metabolomics Core Facility, Clinical Biochemistry Rigshospitalet Copenhagen Denmark
| | - Sarah Joan Blackwood
- Åstrand Laboratory Department of Physiology, Nutrition and Biomechanics Swedish School of Sport and Health Sciences Stockholm Sweden
| | - Abram Katz
- Åstrand Laboratory Department of Physiology, Nutrition and Biomechanics Swedish School of Sport and Health Sciences Stockholm Sweden
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9
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Hickmott LM, Chilibeck PD, Shaw KA, Butcher SJ. The Effect of Load and Volume Autoregulation on Muscular Strength and Hypertrophy: A Systematic Review and Meta-Analysis. SPORTS MEDICINE - OPEN 2022; 8:9. [PMID: 35038063 PMCID: PMC8762534 DOI: 10.1186/s40798-021-00404-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 12/26/2021] [Indexed: 02/07/2023]
Abstract
Background Autoregulation has emerged as a potentially beneficial resistance training paradigm to individualize and optimize programming; however, compared to standardized prescription, the effects of autoregulated load and volume prescription on muscular strength and hypertrophy adaptations are unclear. Our objective was to compare the effect of autoregulated load prescription (repetitions in reserve-based rating of perceived exertion and velocity-based training) to standardized load prescription (percentage-based training) on chronic one-repetition maximum (1RM) strength and cross-sectional area (CSA) hypertrophy adaptations in resistance-trained individuals. We also aimed to investigate the effect of volume autoregulation with velocity loss thresholds ≤ 25% compared to > 25% on 1RM strength and CSA hypertrophy. Methods This review was performed in accordance with the PRISMA guidelines. A systematic search of MEDLINE, Embase, Scopus, and SPORTDiscus was conducted. Mean differences (MD), 95% confidence intervals (CI), and standardized mean differences (SMD) were calculated. Sub-analyses were performed as applicable. Results Fifteen studies were included in the meta-analysis: six studies on load autoregulation and nine studies on volume autoregulation. No significant differences between autoregulated and standardized load prescription were demonstrated for 1RM strength (MD = 2.07, 95% CI – 0.32 to 4.46 kg, p = 0.09, SMD = 0.21). Velocity loss thresholds ≤ 25% demonstrated significantly greater 1RM strength (MD = 2.32, 95% CI 0.33 to 4.31 kg, p = 0.02, SMD = 0.23) and significantly lower CSA hypertrophy (MD = 0.61, 95% CI 0.05 to 1.16 cm2, p = 0.03, SMD = 0.28) than velocity loss thresholds > 25%. No significant differences between velocity loss thresholds > 25% and 20–25% were demonstrated for hypertrophy (MD = 0.36, 95% CI – 0.29 to 1.00 cm2, p = 0.28, SMD = 0.13); however, velocity loss thresholds > 25% demonstrated significantly greater hypertrophy compared to thresholds ≤ 20% (MD = 0.64, 95% CI 0.07 to 1.20 cm2, p = 0.03, SMD = 0.34). Conclusions Collectively, autoregulated and standardized load prescription produced similar improvements in strength. When sets and relative intensity were equated, velocity loss thresholds ≤ 25% were superior for promoting strength possibly by minimizing acute neuromuscular fatigue while maximizing chronic neuromuscular adaptations, whereas velocity loss thresholds > 20–25% were superior for promoting hypertrophy by accumulating greater relative volume. Protocol Registration The original protocol was prospectively registered (CRD42021240506) with the PROSPERO (International Prospective Register of Systematic Reviews). Supplementary Information The online version contains supplementary material available at 10.1186/s40798-021-00404-9.
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Affiliation(s)
- Landyn M Hickmott
- College of Medicine, Health Sciences Program, University of Saskatchewan, Saskatoon, Canada.
| | | | - Keely A Shaw
- College of Kinesiology, University of Saskatchewan, Saskatoon, Canada
| | - Scotty J Butcher
- School of Rehabilitation Science, University of Saskatchewan, Saskatoon, Canada
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10
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Takahashi K, Kitaoka Y, Matsunaga Y, Hatta H. Lactate administration does not affect denervation-induced loss of mitochondrial content and muscle mass in mice. FEBS Open Bio 2021; 11:2836-2844. [PMID: 34510821 PMCID: PMC8487050 DOI: 10.1002/2211-5463.13293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/24/2021] [Accepted: 09/08/2021] [Indexed: 01/01/2023] Open
Abstract
Lactate is considered to be a signaling molecule that induces mitochondrial adaptation and muscle hypertrophy. The purpose of this study was to examine whether lactate administration attenuates denervation-induced loss of mitochondrial content and muscle mass. Eight-week-old male Institute of Cancer Research mice underwent unilateral sciatic nerve transection surgery. The contralateral hindlimb served as a sham-operated control. From the day of surgery, mice were injected intraperitoneally with PBS or sodium lactate (equivalent to 1 g·kg-1 body weight) once daily for 9 days. After 10 days of denervation, gastrocnemius muscle weight decreased to a similar extent in both the PBS- and lactate-injected groups. Denervation significantly decreased mitochondrial enzyme activity, protein content, and MCT4 protein content in the gastrocnemius muscle. However, lactate administration did not have any significant effects. The current observations suggest that daily lactate administration for 9 days does not affect denervation-induced loss of mitochondrial content and muscle mass.
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Affiliation(s)
- Kenya Takahashi
- Department of Sports SciencesThe University of TokyoMeguro‐kuJapan
| | - Yu Kitaoka
- Department of Human SciencesKanagawa UniversityYokohamaJapan
| | - Yutaka Matsunaga
- Department of Sports SciencesThe University of TokyoMeguro‐kuJapan
| | - Hideo Hatta
- Department of Sports SciencesThe University of TokyoMeguro‐kuJapan
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Horwath O, Envall H, Röja J, Emanuelsson EB, Sanz G, Ekblom B, Apró W, Moberg M. Variability in vastus lateralis fiber type distribution, fiber size, and myonuclear content along and between the legs. J Appl Physiol (1985) 2021; 131:158-173. [PMID: 34013752 DOI: 10.1152/japplphysiol.00053.2021] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Human skeletal muscle characteristics such as fiber type composition, fiber size, and myonuclear content are widely studied in clinical and sports-related contexts. Being aware of the methodological and biological variability of the characteristics is a critical aspect in study design and outcome interpretation, but comprehensive data on the variability of morphological features in human skeletal muscle are currently limited. Accordingly, in the present study, m. vastus lateralis biopsies (10 per subject) from young and healthy individuals, collected in a systematic manner, were analyzed for various characteristics using immunohistochemistry (n = 7) and SDS-PAGE (n = 25). None of the analyzed parameters, fiber type % (FT%), type I and II fiber cross-sectional area (fCSA), percentage fiber type area (fCSA%), myosin heavy chain composition (MyHC%), type IIX content, myonuclear content, or myonuclear domain, varied in a systematic manner longitudinally along the muscle or between the two legs. The average within-subject coefficient of variation for FT%, fCSA, fCSA%, and MyHC% ranged between 13% and 18% but was only 5% for fiber-specific myonuclear content, which reduced the variability for myonuclear domain size to 11%-12%. Pure type IIX fibers and type IIX MyHC were randomly distributed and present in <24% of the analyzed samples, with the average content being 0.1% and 1.1%, respectively. In conclusion, leg or longitudinal orientation does not seem to be an important aspect to consider when investigating human vastus lateralis characteristics. However, single muscle biopsies should preferably not be used when studying fiber type- and fiber size-related aspects, given the notable sample-to-sample variability.NEW & NOTEWORTHY This study provides a comprehensive analysis of the variability of key human skeletal muscle fiber characteristics in multiple sites along and between the m. vastus lateralis of healthy and active individuals. We found a notable but nonsystematic variability in fiber type and size, whereas myonuclear content was distinctively less variable, and the prevalence of type IIX fibers was random and very low. These data are important to consider when designing and interpreting studies including m. vastus lateralis biopsies.
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Affiliation(s)
- Oscar Horwath
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Helena Envall
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Julia Röja
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Eric B Emanuelsson
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - Gema Sanz
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden.,Gnomics, Murcia, Spain
| | - Björn Ekblom
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - William Apró
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden.,Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm, Sweden
| | - Marcus Moberg
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden.,Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
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