黄芪多糖对2型糖尿病大鼠肾组织胰岛素信号转导的影响

目的:研究黄芪多糖(APS)对 2 型糖尿病大鼠肾组织胰岛素信号分子表达的影响。方法:Wistar大鼠随机分成正常对照组(Control组)、链脲佐菌素(STZ)糖尿病组(DM组)和糖尿病黄芪多糖治疗组(DM+APS组),5周后观察动物一般情况,处死动物取血测血糖、血清胰岛素水平,用免疫组化的方法检测肾组织中胰岛素受体(InsR)、胰岛素受体底物 1(IRS 1)、磷脂酰肌醇3 激酶(PI3K)表达水平。结果:DM组体重水平高于 Control组和DM+APS组,差别有显著性(P<0.01);DM组和DM+APS组血糖水平均高于 Control组(P<0.01),DM+APS组血糖水平低于DM组(P<0.01);各组间血胰岛素水平差别无显著性(P> 0. 05); DM组肾组织 InsR、IRS 1、PI3K的表达水平均低于Control组和DM+APS组(P<0.05)。结论:黄芪多糖可降低 2 型糖尿病大鼠血糖水平,其机制可能与提高糖尿病大鼠肾组织中 InsR、IRS 1、PI3K水平,增加组织对胰岛素的敏感性,改善胰岛素信号转导有关。

Effects of Astragalus Polysaccharide on Insulin Signal Transduction in Renal Tissue of Type 2 Diabetic Rats

Objective: To investigate effects of astragalus polysaccharide(APS)on expression of insulin signal molecules in renal tissue of type 2 diabetic rats. Methods: Wistar rats were divided into normal control group(control group), streptozotocin(STZ)-induced diabetic model group(DM group)and diabetic model plus astragalus polysaccharide therapy group(DM+APS group)at random. After 5 weeks, the general behaviors of the rats were observed before they were killed, and their blood was extracted for measuring the levels of glucose and serum insulin. Immunohistochemistry was applied to detect the expression levels of InsR, IRS-1 and PI3K in renal tissue. Results: The weight of DM group was significantly higher than that of control group and DM+APS group(P<0.01); the levels of glucose of DM group and DM+APS group were significantly higher than those of control group(P<0.01), and the levels of glucose of DM+APS group were significantly lower than those of DM group(P<0.01); no significant differences were found in the levels of insulin between the groups(P>0.05); the expression levels of InsR, IRS-1 and PI3K of DM group were significantly lower than those of both control group and DM+APS group in renal tissue(P<0.05). Conclusion: APS could decrease the levels of glucose in type 2 diabetic rats, and its pharmaceutical mechanisms might be closely related with the elevation of the levels of InsR, IRS-1 and PI3K in renal tissue of diabetic rats, increasing of insulin sensitivity and improvement of insulin signal transduction in target tissues.