Myokine Expression in Muscle and Myotubes in Response to Exercise Stimulation.

• Autores: J.D. Covington, Robert C. Noland, Charmaine S Tam, Sudip Bajpeyi, Steven Smith, Leanne Maree Redman, Eric Ravussin, José Eduardo Galgani Fuentes
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 48, Nº. 3, 2016, págs. 384-390
• Idioma: inglés
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• Dialnet Métricas: 1 Cita
• Resumen

  • AB Purpose: Myokines have been shown to affect muscle physiology and exert systemic effects. We endeavored to investigate a panel of myokine mRNA expression after a single exercise bout (studies 1 and 2) to measure myokine mRNA in primary human myotubes in an in vitro exercise model (study 2). Methods: Vastus lateralis muscle biopsies were obtained from 20 healthy males (age, 24.0 +/- 4.5 yr; BMI, 23.6 +/- 1.8 kg[middle dot]m-2) before and after a single exercise bout (650 kcal at 50% V[spacing dot above]O2max). Primary myotubes from active and sedentary male donors were treated with a pharmacological cocktail (palmitate, forskolin, and ionomycin (PFI)) to mimic exercise-stimulated contractions in vitro. Results: Interleukin 6 and 8 (IL-6 and IL-8), leukocyte-inducing factor, and connective tissue growth factor (CTGF) mRNA levels increased approximately 10-fold after a single exercise bout (all P < 0.001), whereas myostatin levels decreased (P < 0.05). Key correlations between myokine expression and parameters of muscle and whole-body physiology were found: myostatin versus skeletal muscle citrate synthase activity (r = -0.69, P < 0.001), V[spacing dot above]O2max (r = -0.64, P = 0.002) and the percentage of Type I fibers (r = -0.55, P = 0.01); IL-6 versus the RER (r = 0.45, P = 0.04), homeostatic model assessment of insulin resistance (r = 0.44, P = 0.05), and serum lactate (r = 0.50, P = 0.02). Myokine expressions in myotubes from sedentary donors for CTGF and myostatin decreased, whereas IL-6 and IL-8 increased after PFI treatment. In myotubes from active donors, myokine expression increased for IL-6, CTGF, and myostatin but decreased for IL-8 after PFI treatment. Conclusion: These data offer insight into the differences in regulation of myokine expression and their possible physiologic relationships.