The purpose of the present study to was to to examine the effects of low testosterone on muscle mass and function in rats following 10 days of hindlimb immobilization and determine if a high protein diet enhances load-mediated hypertrophy. Average SOL CSA was significantly lower for immobilized vs. control legs at 0 (30.3%, p < 0.001) and 14 days of reloading (15.9%, p = 0.006). Significant differences in average soleus mass were present at all days of reloading (all p < 0.001). Immobilized SOL Po followed a similar pattern (all p < 0.001), and castrated animals showed lower Po at 14 days (p < 0.050). At present, functional overload in a testosterone-deprived state appears to reduce the regrowth of skeletal muscle size, suggesting that testosterone may play a role in load-mediated hypertrophy following immobilization. As well, a high protein diet did not result in enhanced load-mediated hypertrophy in castrated rats.Master of Art
