Effects of diet and exercise on the expression of glycogen synthase kinase-3 in skeletal muscle of rats with insulin resistance

【Objective】To observe the effects of diet and exercise on the expression of GSK-3 in skeletal muscle of rats with insulin resistance induced by high-fat and sucrose diets.【Methods】40 Wistar rats were divided into four groups medially and randomly:control group,model group,diet group and exercise group. The model group,diet group and exercise group were given the high-fat and sucrose diets (20% sucrose,10% lard,2.5% cholesterol,1% cholic acid) for 4 weeks. Then diet group were fed with normal diets and exercise group were trained by swimming regularly for 6 weeks. At the end of the experiment,GSK-3 protein was detected by Western blot analysis. Body weight,serum triglyceride and cholesterol,fasting plasma glucose and serum insulin concentration were measured timely and insulin sensitivity index was computed as well.【Results】The outcome of Western blot showed that the expression of GSK-3 in skeletal muscle of model group rats increased by 70.20% (P 0.01) compared with control group rats. After 6 weeks of diet-control or exercise training,the GSK-3 protein in skeletal muscle of diet group and exercise group rats decreased by 23.22% (P 0.01) and 27.24% (P 0.01) respectively compared with model group rats. 【Conclusion】Not only diet control but also exercise training can lower the expression of GSK-3 in skeletal muscle of insulin resistance rats,consequently promoting the uptake and utilize of glucose,to improve the insulin resistance.