Influence of resistance exercise intensity and metabolic stress on anabolic signaling and expression of myogenic genes in skeletal muscle

Authors


  • This work was supported by the M.V. Lomonosov Moscow State University Program of Development; the program of the Presidium of the Russian Academy of Sciences, “Molecular Mechanisms of Physiological Functions”; and by a grant from the Russian Foundation for Basic Research (12-04-01668-а).

ABSTRACT

Introduction: We investigated the effect of resistance exercise intensity and exercise-induced metabolic stress on the activation of anabolic signaling and expression of myogenic genes in skeletal muscle. Methods: Ten strength-trained athletes performed high-intensity [HI, 74% of 1-repetition maximum (RM)], middle-intensity (MI, 54% 1RM), or middle-intensity (54% 1RM) no-relaxation exercise (MIR). Kinase phosphorylation level and myogenic gene expression in muscle samples were evaluated before, 45 min, 5 h, and 20 h after exercise. Results: The lactate concentration in MI was approximately 2-fold lower than in the 2 other sessions, and was highest in MIR. The phosphorylation level of extracellular kinase 1/2Thr202/Tyr204 after exercise was related to metabolic stress. Metabolic stress induced a decrease in myostatin mRNA expression, whereas mechano-growth factor mRNA level depended on exercise intensity. Conclusions: This study demonstrates that both intensity and exercise-induced metabolic stress can be manipulated to affect muscle anabolic signaling. Muscle Nerve 51: 434–442, 2015

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