糖尿病大鼠肾脏细胞凋亡的研究

目的 :探讨糖尿病肾皮质细胞凋亡的发生以及细胞凋亡与糖尿病肾病之间的关系。方法 :应用链脲佐菌素 (streptozotocin ,STZ)加高能量饮食建立 2型糖尿病大鼠模型 ,并设立对照组 ,19周后观察两组血糖和血胰岛素释放水平 ,同时测定肾功能 ;采用原位末端标记法 (TUNEL)及琼脂糖凝胶电泳检测大鼠肾皮质细胞凋亡 ;以免疫组化方法检测凋亡相关基因bcl 2、Bax的表达。结果 :与对照组相比 ,糖尿病组肾小管和肾间质凋亡细胞数明显增多(P <0 .0 0 1) ,bcl 2基因表达下调 (P <0 .0 1) ,Bax基因表达上调 (P <0 .0 1) ;琼脂糖凝胶电泳示凋亡特有的梯状 (lad der)图谱。结论 :糖尿病肾脏细胞凋亡主要发生于肾小管上皮和肾间质细胞 ,糖尿病时持续高血糖造成的高渗透压可能是诱导细胞凋亡的机制之一 ,细胞凋亡与早期糖尿病肾病的发生关系密切。

Preliminary Study on Cell Apoptosis and Expression of Its Associated Genes in the Renal of Diabetic Rats

Objective: To explore the cell apoptosis in renal cortex and the relationship between apoptosis and pathogeneses of diabetic nephropathy. Methods: Type 2 Diabetes was induced in rats by injection with half of the regular dose of streptozotocin(STZ,30 mg/kg body weight) via tail vein and high calorie for 19 weeks (fed on a diet of height fat and high calorie for 19 weeks), then blood glucose and insulin concentration were determined. During experimental period, apoptosis was evaluated by agarose gel electrophresis and terminal deoxynudeotidyl transferase mediated d UTP nick end labeling (TUNEL). Immunohistochemistry was used to detect apoptosis associated gene expression in renal cortex. Results: Apoptosis of cells were mostly occurred in renal tubular and intistiamal.TUNEL staining show rate of the type 2 Diabetics group was obviously higher than that of control group about level of apoptosis(P<0.001). Clear DNA ladder could be found in the specimens of the type 2 Diabetics group, while the control group had no ladder through agarose gel electrophoresis. Image analysis show the OD values of bcl 2 protein decreased (P<0.01) while Bax protein increased significantly (P<0.01) compared with control group. Conclusion: Cell apoptosis occurs in renal tubular and intistiamal,and bcl 2/Bax gene is important in regulating apoptosis. An intimate relationship exists between apoptosis and early diabetic nephropathy.