Exercise alters myostatin protein expression in sedentary and exercised streptozotocin-diabetic rats.

OBJECTIVE The aim of this study was to analyze the effect of exercise on the pattern of muscle myostatin (MSTN) protein expression in two important metabolic disorders, i.e., obesity and diabetes mellitus. MATERIALS AND METHODS MSTN, is a negative regulator of skeletal muscle mass. We evaluated the effect of exercise on MSTN protein expression in diabetes mellitus and high fat diet-induced obesity. MSTN protein expression in gastrocnemius muscle was analyzed by Western Blot. P < 0.05 was assumed. Exercise induced a significant decrease in glycemia in both diabetic and obese animals. RESULTS The expression of precursor and processed protein forms of MSTN and the weight of gastrocnemius muscle did not vary in sedentary or exercised obese animals. Diabetes reduced gastrocnemius muscle weight in sedentary animals. However, gastrocnemius muscle weight increased in diabetic exercised animals. Both the precursor and processed forms of muscle MSTN protein were significantly higher in sedentary diabetic rats than in control rats. The precursor form was significantly lower in diabetic exercised animals than in diabetic sedentary animals. However, the processed form did not change. CONCLUSION These results demonstrate that exercise can modulate the muscle expression of MSTN protein in diabetic rats and suggest that MSTN may be involved in energy homeostasis.