饮食控制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 观察饮食控制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、胰岛素抵抗组和饮食治疗组，每组10只。正常组以常规饲料喂养，胰岛素抵抗组和饮食治疗组均以高糖高脂饲料喂养，4周后饮食治疗组大鼠改以常规饲料喂养，持续6周。采用Western blotting法检测各组大鼠骨骼肌中GSK-3的表达，于实验第1、5和11周分别检测其体质量、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 胰岛素抵抗组大鼠骨骼肌GSK-3的表达量较正常组增高70％（P〈0．01），饮食控制6周后饮食治疗组大鼠骨骼肌中GSK．3的表达量较胰岛素抵抗组减少23％（P〈0．01），较正常组增高31％（P〈0．05）。而饮食治疗组的胰岛素敏感指数与胰岛素抵抗组相比明显上升（P〈0．05）。结论 饮食控制可降低胰岛素抵抗大鼠骨骼肌细胞GSK-3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 Diet Control on the Expression of Glycogen Synthase Kinase-3 in Skeletal Muscle of Rats with Insulin Resistance

Objective To observe the effects of diet control on the expression of glycogen synthase kinase-3 (GSK-3) in skeletal muscle of rats with insulin resistance induced by high-fat and high-carbohydrate diets. Methods Thirty Wistar rats were randomly divided into normal control group,insulin resistance group,and diet treatment group. The normal control group was fed with normal diets all along the study course. The insulin resistance group and diet treatment group were initially given the high-fat and high-carbohydrate diets (20% sucrose,10% lard,2.5% cholesterol,1% cholic acid) for 4 weeks,then the diet treatment group were changed with normal diets for 6 weeks. At the end of the experiment,GSK-3 protein at each group was detected with Western blotting. Body weight,serum triglyceride and cholesterol,and fasting plasma glucose, and serum insulin concentration were measured in the 1st,5th,and 11th week, respectively, and insulin sensitivity index was calculated as well. Results Western blotting showed that the expression of GSK-3 in skeletal muscle of rats in insulin resistance group increased by 70% (P < 0.01) compared with that of rats in normal control group. After 6 weeks of diet control,the GSK-3 protein in skeletal muscle of rats in diet treatment group decreased by 23% (P < 0.01) compared with that of rats in insulin resistance group.The insulin sensitivity index of rats in diet treatment group was significantly higher than that of rats in insulin resistance group (P < 0.05). Conclusion Diet control can lower the expression of GSK-3 in skeletal muscle of rats with insulin resistance,and consequently improve the insulin resistance and promote the uptake and utilization of glucose.