High-intensity resistance training attenuates dexamethasone-induced muscle atrophy

IntroductionIn this study we investigated the effects of high-intensity resistance training (RT) on dexamethasone (DEX)-induced muscle atrophy in flexor hallucis longus (FHL), tibialis anterior (TA), and soleus (SOL) muscles. Methods: Rats underwent either high-intensity RT or were kept sedentary. In the last 10 days they received either DEX (0.5mg/kg/day, intraperitoneally) or saline. Results: DEX reduced body weight (-21%), food intake (-28%), FHL and TA muscle mass (-20% and -18%, respectively), and increased muscle-specific ring finger 1 (MuRF-1) protein level (+37% and +45.5%). RT attenuated FHL muscle atrophy through a combination of low increase in MuRF-1 protein level (-3.5%) and significant increases in mammalian target of rapamycin (mTOR) (+63%) and p70S6K (+46% and +49% for control and DEX, respectively) protein levels. Conclusion: RT attenuated DEX-induced muscle atrophy through a combination of increases in mTOR and p70S6K protein levels and a low increase in MuRF-1 protein level. Muscle Nerve53: 779-788, 2016