الفهرس | Only 14 pages are availabe for public view |
Abstract The aim of the present study was to investigate the possible protective role of physical exercise and vitamin D on serum level of IGF-1 and skeletal muscle autophagy with their subsequent impact on the contractile properties of skeletal muscles in diabetic rats. This study was conducted on 40 male Sprague Dawely rats. The animals were divided into 5 experimental groups; (8 rats in each group). Rats of group I; served as control group, group II; untreated diabetic rats, group III; diabetic rats maintained on daily swimming exercise 1 hr/day, 5 days/week for 8 weeks, group IV; diabetic rats maintained on vitamin D supplementation (10 IU/kg) by gavage for 8 weeks, group V; diabetic rats maintained on daily swimming exercise with vitamin D supplementation for 8 weeks. At the end of experimental protocol, the animals were anaesthetized and blood samples were collected for biochemical analysis then scarifying was done to obtain soleus (type I; slow twitch) and tibialis anterior (type II; fast twitch) muscles. The contractile properties of muscles were recorded by Biopac apparatus. Histophathological examination of the muscle fibers using Hematoxylin and Eosin was done. Also the expression of autophagy marker (LC3) by western blot analysis was performed. The results obtained from this study showed: DM revealed a significant increase in fasting blood glucose, fasting insulin, HOMA-IR value and in autophagy markers with decrease in serum level of IGF-1. Regarding the contractile properties of skeletal muscles, they were significantly affected with diabetes mellitus and the histopathological examination showed affection of the muscles like widened interstitial tissue spaces and myophagia in comparsion with normal group with more affection of fast twitch fibers than slow. Our study showed that treatment either by vitamin D or exercise leads to an improvement in all studied parameters with more improvement in the group received combination of treatment. |