生活方式干预对胰岛素抵抗大鼠脂肪组织中GSK-3β表达的影响

Effect of Life-Style Intervention on Expression of GSK-3β in Adipose Tissue of Rats with Insulin Resistance

目的探讨生活方式干预对高脂饮食诱导的胰岛素抵抗大鼠脂肪组织中糖原合成酶激酶3β(GSK-3β)表达的影响。方法40只SPF级雄性Wistar大鼠随机分为2组,正常对照组10只,普通饲料喂养;模型组30只,高脂饲料喂养。4周后模型形成,模型组随机等分为3个亚组(胰岛素抵抗组、饮食干预组、运动干预组),对照组和饮食干预组喂以普通饲料,另外2组续以高脂饲料喂养;运动干预组大鼠进行游泳运动。干预6周后,用Western-blot方法检测各组大鼠附睾脂肪组织中GSK-3β的表达水平;定期检测大鼠体重(BW)、空腹血糖(FPG)及血浆胰岛素(FINS)、血甘油三酯(TG)和胆固醇(TC),并计算胰岛素敏感指数(ISI)。结果(高脂饲料喂养4周后,与正常对照组比较,模型组大鼠BW、FPG、FINS、TC、TG显著升高(P<0.05或P<0.01),ISI显著下降(P<0.01),胰岛素抵抗模型诱导成功。)与正常对照组比较,胰岛素抵抗组GSK-3β的表达上升(P<0.01),而干预组大鼠GSK-3β的表达均无显著差异;与胰岛素抵抗组大鼠比较,2个干预组大鼠脂肪组织中GSK-3β的表达均下降(P<0.05);2个干预组间GSK-3β的表达无显著差异。结论生活方式干预显著下调脂肪组织GSK-3β的表达,并且参与其改善胰岛素抵抗的机制。

Objective To investigate the effect of life- style intervention on expression of Glucogen Synthase Kinase-3 beta（GSK-3β） in adipose tissue of rats with insulin resistance induced by high - fat diet. Methods The 40 Wistar rats were randomized into two groups： control group（n = 10） and model group（n =30）. Control group were fed with common diet, while model group were fed with high - fat diet to induce insulin resistance. After 4 weeks, the models have formed then were randomized into three subgroups, insulin resistance group （n = 10）, diet treatment group （n = 10） and exercise treatment group （n = 10）. Control group and diet group were fed with common diet, while the others were fed with high fat - diet. And exercise group were trained by swimming. After 6 weeks, GSK -3β protein was detected by Western - blot analysis. Body weight, serum triglyceride and cholesterol, fasting plasma glucose and serum insulin concentration were detected termly and the insulin sensitivity index was calculated. Results （1） Compared with control group, serum triglyceride and cholesterol, fasting plasma glucose and serum insulin concentration of model group increased （P 〈 0.05 or P 〈 0. 01 ） and insulin resistance index （ISI） decrease（P 〈 0.01 ） by high - fat diets, insulin resistance was induced by this way; （2） Compared with control group, expression of GSK-3β protein in adipose tissue of insulin resistance group rats increased（P 〈0.01 ）and two treatment groups had no difference. Compared with insulin resistance group, expression of GSK-3β protein in adi-pose tissue of diet group and exercise group rats decreased （P 〈 0. 05）. Between treatment groups, expression of GSK- 313 protein in adipose tissue had no difference. Conclusion Life - style intervention can decrease the expression of GSK-3β protein in adipose tissue of rats with insulin resistance which was involved in the mechanism of amelioration the state of insulin resistance.