胰岛素抵抗大鼠血糖正常阶段肾皮质血管内皮功能的改变

目的通过检测肾皮质内皮素1（ET-1）、内皮型一氧化氮合酶（eNOS）的表达，研究胰岛素抵抗（IR）大鼠血糖正常阶段肾皮质血管内皮功能的改变。方法以免疫组织化学、RT-PCR方法检测IR大鼠模型肾皮质ET-1、eNOS蛋白和mRNA表达的改变。结果与正常大鼠相比，IR大鼠SBP、TG、FFA、Ins水平升高（P均〈0．01），胰岛素敏感指数、HDL-C降低（P均〈0．01）。FBG、2hBG在正常范围。HE染色IR组大鼠肾皮质出现组织学的异常改变，肾皮质ET-1蛋白及mRNA表达升高，eNOS蛋白和mRNA表达减低。结论IR大鼠模型在血糖正常阶段已存在肾皮质ET-1与eNOS平衡的异常，表明在IR早期已存在肾血管内皮功能的损害。

Abnormal angio-endothelium function in renal cortex of insulin-resistant rats at normal blood glucose stage

Objective To investigate the angio-endothelium function of kidney of insulin-resistant rats at normal blood glucose stage by assaying the expressions of ET-1 and eNOS at the renal cortex. Methods Insulin-resistant (IR) rat model(n=10) was prepared from Sprague-Dawley(SD) rats at age of 6~8 weeks by high-glucose diet (70% calories from glucose)for 12 weeks.Normal diet SD rats (n=10) were used as a control group(NC).The protein and mRNA of ET-1 and eNOS in renal cortex were assayed by immunohistochemistry and RT-PCR. Results Systolic blood pressure(SBP) and serum triglyceride(TG),free fatty acid(FFA),insulin(Ins) were higher in IR group than in NC group (all P<0.01).Serum high-density lipoprotein(HDL-C) and insulin sensitiving index(ISI) were lower in IR group than in NC group (both P<0.01).Fasting blood glucose(FBG) and postprandial blood glucose(2 hBG) in NC group were within normal range.HE stain showed the abnormal changes in glomerulus, renal tubules and renal interstitial in IR group.The levels of ET-1 protein and mRNA of renal cortex were higher in IR group than in NC group.The levels of eNOS protein and mRNA of renal cortex were lower in IR group than in NC group(all P<0.01). Conclusion In IR rats,the abnormal balance of ET-1 and eNOS in renal cortex occurs at normal blood glucose stage.