Comparison Of Effects Of Different Exercise Modes On Gastrocnemius Of Obese Rats

Abstract

PURPOSE: To explore the effects of different exercise patterns on gastrocnemius in obese rats. METHODS: Forty-eight SD rats were randomly divided into 4 groups, 12 in each group, which were quiet control group(Con), continuous exercise group (CE), high-intensity intermittent exercise group (HIIT) and ladder exercise group (LE). After 8 weeks of exercise training, each exercise group was anesthetized including quiet control group and samples were collected for testing. The body weight and gastrocnemius weight of each group were recorded. The cross-sectional area of ​​gastrocnemius muscle was observed by HE staining. The levels of MSTN and insulin in serum were detected by ELISA. The expressions of MSTN, IGF1 and p70S6K in rat gastrocnemius muscle were detected by Western blot. RESULTS: Compared with the group Con, the body weights of group CE, HIIT, LE were reduced by 13.8%,14%,10%, and the weight of the gastrocnemius muscles in group HIIT was decreased by 22%. Compared with the group Con, the gastrocnemius mass index of group CE and group LE was increased by 10.7%. Morphological observation of the gastrocnemius showed that compared with the group Con, the gastrocnemius muscle cross-section of the group LE was increased by 17%. The serum GDF8 level in the group CE was reduced by 32% than that in the group Con, and the serum insulin level in the group CE and group HIIT was decreased by 42% and 35%. Compared with the group Con, the expression of GDF8 and P70S6K protein in the gastrocnemius muscle of the group CE and group HIIT was reduced by 31%, 26%,13% and 21% respectively, while the expression of IGF1 protein in the three exercise groups was increased by 6%,40% and190% respectively. CONCLUSION: Although the three exercise modes may significantly reduce the body weight of rats, only continuous exercise and ladder exercise improve the gastrocnemius muscle mass index. Continuous exercise and high-intensity intermittent exercise had similar effects on serum GDF8, insulin, and similar effects on the proteins of MSTN, IGF1 and P70S6K in the gastrocnemius muscle, but the effects of three exercise modes on serum GDF8 and insulin and gastrocnemius MSTN, IGF1 and P70S6K proteins, laddering exercise is different from sustained exercise and High intensity intermittent exercise.