Effects of Aerobic Exercise on the Intramuscular Lipid and Glycogen Content of Fiber Types in Soleus Muscles of Non-Alcoholic Steatohepatitis Model Rats

We studied the effects of exercise on muscle mitochondria, and lipid and glycogen content in nonalcoholic steatohepatitis (NASH) model rats. Male Sprague-Dawley rats were randomly separated into 3 groups: the control group was fed standard chow; the NASH group was fed a methioninecholine-deficient high-fat diet (MCD); the NASH-exercise group was fed the MCD and exercised three times a week. Exercise training consisted of continuous running for thirty minutes at a 13 m/min, 6 ̊ slope on a motor-driven rodent treadmill for 6 weeks. Mitochondria content in NASH group decreased in the both fiber types compared with those of the control group. As compared between the NASH and NASH-exercise groups, however, exercise not only promoted significant improvements in liver fibrosis and cirrhosis and triglyceride (TG) content but also increased mitochondria content in type I muscle fiber in particular. These data suggest that exercise improved hepatic steatosis in NASH model rats and can prevent the progression of NASH.