The effect of 6 weeks moderate intensity endurance training on skeletal muscle fibrosis in diabetic rats

Background: Diabetes leads to both structural and functional dysfunction in the tissues and causes problems such as fibrosis. The purpose of this study was to investigate the effect of 6 weeks moderate intensity endurance training on skeletal muscle fibrosis in diabetic rats. Methods: Twenty eight adult male wistar rats in the weight range of 200-250gr, randomly assigned to four equal groups: diabetes and training, diabetes control, healthy and training, healthy control. After twelve hours of food deprivation, intraperitoneal injection of Streptozotocin solution method was used. Two weeks after STZ injection, the moderate intensity endurance training protocol was performed for six weeks. Twenty four hours after the last training session, soleus and EDL muscles were dissected. Mason’s trichrome staining method was used for analysis of fibrosis. Results: Compared with the healthy control group, diabetes caused a significant increase in fibrosis in soleus muscle (P=0.002) and extensor digitorum longus muscle (P=0.048). Also, endurance training resulted in significant reduction of fibrosis in soleus muscle in the Diabetes and training group compared to the diabetes control group (P=0.043), but endurance training did not have a significant effect on fibrosis of the extensor digitorum longus muscle (P=0.341). The exercise also significantly reduced blood glucose levels in the diabetic group compared to the control group. Conclusion: It seems that moderate intensity endurance training could inhibit from muscle fibrosis caused by diabetes. So, it is suggested that moderate intensity endurance training could be used as a non-pharmacotherapy intervention for inhibition of fibrosis in diabetic patient’s muscles.