动物造模 z-bio 2022-12-01 248

　　Objective To explore the effects of different exercise modes on MSTN and IGF1 of skeletal muscle in rats, and to provide theoretical basis for selecting appropriate exercise modes to improve skeletal muscle function.

　　Methods Forty SD rats were randomly divided into four groups, 10 rats in each group, which were quiet control group, continuous swimming group, high-intensity intermittent swimming group and weight-bearing ladder climbing group. After eight weeks of exercise training, each exercise group and the quiet control group were anesthetized and killed, and samples were collected. The weight and mass of gastrocnemius muscle of rats in each group were recorded. The changes of cross sectional area of gastrocnemius muscle were observed by HE staining. The levels of MSTN, IGF1 and insulin in serum of rats were detected by ELISA. The expressions of MSTN, IGF1 and p70S6K in gastrocnemius muscle of rats were detected by Western blot.

　　Results The weight of rats in the three exercise groups was significantly lower than that in the quiet control group (P<0.01), the weight of gastrocnemius muscle in the continuous swimming exercise group was significantly lower than that in the quiet control group (P<0.05), and="" the="" weight="" of="" gastrocnemius="" muscle="" in="" other="" two="" groups="" did="" not="" change="" significantly="" p="">0.05); The cross sectional area of gastrocnemius muscle in the three exercise groups was significantly lower than that in the quiet control group (P<0.05), and the cross sectional area of gastrocnemius muscle in the stair climbing exercise group and the high-intensity intermittent swimming exercise group was significantly higher than that in the continuous swimming exercise group (P<0.05). The results of ELISA showed that the serum IGF1 levels in the three exercise groups were significantly lower than those in the quiet control group (P<0.01), while the levels of MSTN and insulin were not significantly changed. The expression of MSTN protein in gastrocnemius muscle of climbing exercise group was significantly lower than that of quiet control group (P<0.01), while the expression of IGF1 and P70S6K protein was significantly higher than that of quiet control group (P<0.01), and the expression of p70S6K protein in gastrocnemius muscle of continuous swimming exercise group was also significantly higher than that of quiet control group (P<0.05).

　　Conclusion Compared with the three types of exercise, stair climbing exercise and high-intensity intermittent swimming exercise both increase the gastrocnemius mass index, but have different effects on MSTN and IGF1 of skeletal muscle. Climbing exercise down regulated the expression of MSTN and up regulated the expression of IGF1 and p70S6K, while high-intensity intermittent swimming exercise had no significant effect on the expression of MSTN, IGF1 and p70S6K in skeletal muscle. Ladder climbing exercise may increase the cross sectional area of gastrocnemius muscle by decreasing MSTN and increasing the protein expression of IGF1 and P70S6K.