小檗碱改善2型糖尿病大鼠胰岛素抵抗与PI-3K、GLUT4蛋白相关性的研究

目的观察小檗碱对2型糖尿病大鼠骨骼肌组织磷脂酰肌醇3激酶(phosphatidylinositol-3-kinase,PI-3K)之p85亚基、葡萄糖转运子4(glucose transporter4,GLUT4)蛋白表达的影响,以探讨小檗碱改善胰岛素抵抗,防治2型糖尿病的分子机制。方法采用尾静脉注射小剂量链脲佐菌素(streptozotocin,STZ,30mg.kg-1)加高脂高热量饲料喂养的方法建立2型糖尿病大鼠模型,以小檗碱干预10wk,检测血糖和血清胰岛素,用Western blot方法检测小檗碱干预后2型糖尿病大鼠骨骼肌组织PI-3K之p85亚基、GLUT4蛋白表达水平。结果小檗碱干预的2型糖尿病大鼠骨骼肌组织PI-3K之p85亚基、GLUT4蛋白表达水平均较模型组显著增加。结论小檗碱对2型糖尿病的治疗效应可能与提高骨骼肌组织中PI-3K之p85亚基、GLUT4蛋白表达水平有关。

Correlation between the amelioration of insulin resistance and protein expression of PI-3K and GLUT4 in type 2 diabetic rats treated with berberine

Aim To investigate the molecular mechanism of berberine in ameliorating insulin resistance and treating type 2 diabetes mellitus(T2DM),and to observe the effects of berberine on phosphatidylinositol-3-kinase(PI-3K)and glucose transporter 4(GLUT4)protein expression in skeletal muscle of T2DM rat models.Methods The T2DM models were induced by intravenous injection of a small dose of streptozotocin(STZ,30 mg·kg-1)plus high fat and high caloric laboratory chow.Then diabetic animals were divided into model group,aspirin and berberine group.Meanwhile,animals without any treatment were used as normal control.Ten weeks later,oral glucose tolerance test(OGTT)was performed in all groups,the changes of rat body weight,fasting blood glucose(FBG),fasting serum insulin(FINS)and the protein expression of PI-3K p85 and GLUT4 in skeletal muscle before and after insulin treatment were routinely determined.Results Compared with the model group,the result of OGTT of berberine group was improved.The levels of the body weight and FBG decreased,PI-3K p85 and GLUT4 protein expressions in skeletal muscle were elevated obviously as well.Conclusion The therapeutic effects of berberine on T2DM might be related with its ability of increasing PI-3K p85 and GLUT4 protein expression in skeletal muscle of T2DM rats.