电针调控骨骼肌胰岛素受体底物-1磷酸化改善胰岛素抵抗的机制

目的:观察电针对2型糖尿病大鼠骨骼肌胰岛素受体底物-1(IRS-1)磷酸化水平的影响,从而探讨电针治疗2型糖尿病的可能机制。方法:采用2型糖尿病肥胖大鼠作为研究对象。将成模后的14只ZDF大鼠随机分为模型组、电针组,每组7只;另将7只ZL大鼠设为空白组。干预4周,检测空腹血糖(FBG),并以Western Blot法检测IRS-1酪氨酸与丝/苏氨酸磷酸化的水平,观察骨骼肌全细胞葡萄糖转运蛋白4(GLUT4)水平。结果:与模型组比较,电针组大鼠FBG、血清胰岛素(FINS)水平、胰岛素抵抗指数(HOMA-IR)均显著降低(P<0.05),且电针组可显著降低大鼠骨骼肌IRS-1丝/苏氨酸磷酸化水平,提高大鼠骨骼肌IRS-1酪氨酸磷酸化表达(P<0.05)。电针组比空白组及模型组GLUT4蛋白表达水平增高(P<0.05)。结论:电针可降低2型糖尿病ZDF大鼠FBG、FINS、HOMA-IR,同时电针可有效上调骨骼肌GLUT4蛋白表达水平,从而改善其胰岛素抵抗状况,其机制可能与电针调控骨骼肌IRS-1磷酸化水平有关。

Mechanism of electro-acupuncture regulating IRS-1 phosphorylation in skeletal muscle to improve insulin resistance

Objective:To observe the effect of electro-acupuncture on the phosphorylation level of IRS-1 in the skeletal muscle of type 2 diabetic rats,so as to explore the possible mechanism of electro-acupuncture treatment of type 2 diabetes.Methods:Obese rats with type 2 diabetes were used as the research object.The 14 ZDF rats were randomly divided into model group and electro-acupuncture group,7 in each group;7 ZL rats were set as control group.After 4 weeks of intervention,fasting blood glucose(FBG)was detected and the phosphorylation level of IRS-1 tyrosine and serine/threonine was detected by Western Blot method,and the GLUT4 level of skeletal muscle whole cells was observed.Results:The FBG,serum insulin(FINS)level and homa insulin resistance index(HOMA-IR)of the electro-acupuncture group were lower than that of the model group(P<0.05).Electro-acupuncture group reduced the phosphorylation level of IRS-1 serine/threonine in rat skeletal muscle and increased the expression of IRS-1 tyrosine phosphorylation in rat skeletal muscle(P<0.05).The expression level of GLUT4 protein in the electro-acupuncture group was higher than that in the control group and model group(P<0.05).Conclusion:Electro-acupuncture can reduce FBG,FINS and HOMA-IR of type 2 diabetic ZDF rats.At the same time,electro-acupuncture can effectively increase the expression level of GLUT4 protein in skeletal muscle,thereby improving its insulin resistance status.The mechanism may be related to the regulation of skeletal muscle IRS-1 phosphorylation by electroacupuncture.