运动对胰岛素抵抗大鼠骨骼肌中糖原合成酶激酶-3表达的影响

目的 观察运动训练对高脂高糖饮食诱导的胰岛素抵抗模型大鼠骨骼肌中糖原合成酶激酶-3（GSK-3）表达的影响。方法 将30只Wistar大鼠随机分为正常组、模型组和运动组，每组10只。模型组和运动组均喂以高糖高脂饲料，4周后运动组在继续高糖高脂饲料的基础上加以每周游泳5d，连续6周。实验结束后采用Western blot法检测各组大鼠骨骼肌中GSK-3的含量，定期检测其体重、血甘油三脂和胆固醇、空腹血糖和胰岛素水平，并计算胰岛素敏感指数。结果 模型组大鼠骨骼肌中GSK-3的含量较正常组增高70．20％（P〈0．01），游泳训练6周后大鼠骨骼肌中GSK-3的含量较模型组减少27．24％（P〈0．01），较正常组增高23．83％（P〈0．05）。结论 运动训练可降低胰岛素抵抗大鼠骨骼肌细胞GSK-3蛋白表达水平，从而加强葡萄糖的摄取和利用，改善胰岛素抵抗。

Effects of exercise on the expression of glycogen synthase kinase-3 in the skeletal muscles of insulin resistant rats

Objective To observe the effects of exercise training on the expression of glycogen synthase ki-nase-3 (GSK-3) in the skeletal muscles of rats with insulin resistance induced by a high-fat and high sucrose diet. Methods Thirty Wistar rats were randomly divided into three groups: a control group, a model group and an exercise group. Rats in the model and exercise groups were fed with a high-fat and sucrose diet (20% sucrose, 10% lard, 2.5% cholesterol, 1% cholic acid) for 4 weeks, and then the rats in the exercise group were trained by swimming 5 d every week for 6 weeks. After treatment, the concentration of GSK-3 protein in their muscles was detected by Western blot analysis, while their weights, serum triglyceride and total cholesterol, and their concentrations of fasting plasma glucose and fasting plasma insulin were measured periodically and their insulin sensitivity index was calculated. Results Compared with the controls, the expression of GSK-3 in the skeletal muscles of the rats in the model group increased by 70. 20% (P < 0. 01) , while the expression of GSK-3 protein in the exercise group was less by 27.24% (P<0.01) than that in the model group. Conclusion The expression of GSK-3 in the skeletal muscles of rats with insulin resistance could be decreased by exercise training, which might ameliorate the insulin resistance by promoting the uptake and utilization of glucose.