二甲双胍对糖尿病大鼠的心肌保护作用

目的探讨二甲双胍对链脲佐菌素（STZ）糖尿病（DMD大鼠心肌的保护作用。方法用STZ制成DM大鼠模型。雄性SD大鼠60只随机分为正常对照组（Nc）、糖尿病对照组（DC）、胰岛素治疗组（DR）、二甲双胍治疗组（DT）。成模后第4天各组大鼠分别采用不同药物治疗，12周后测血糖、血脂、肾功能、果糖胺、血浆C肽、血浆胰岛素，并取左室心肌组织行光镜及电镜观察。结果与NC组比较，DT组血糖、血脂明显下降（P〈0．05），肾功能无异常；DT组与DR组的甘油三酯和低密度脂蛋白均较NC组高；DT组、DC组、DR组之间心重／体重比较无差异；DT组C肽水平与DC组比较无差异（P〉0．05），血浆胰岛素水平与NC组比较无差异（P〉0．05）。二甲双胍治疗可显著减轻DM大鼠心肌超微结构的病理改变。结论二甲双胍对DM大鼠心肌有一定保护作用。

The protective effect of metformin on the myocardium of diabetic rats

Objective To evaluate the protective effect of metformin on the myocardium of STZ diabetic rats. Methods Male SD rats were randomly divided into 4 groups: normal control group (NC), diabetes control group (DC), diabetes with insulin treatment group (DR), and diabetes with metformin treatment group (DT). Diabetes was produced in rats by giving streptozotocin (STZ). Treatment was begun on the 4th day after the establishment of diabetes. 12 weeks later levels of blood glucose and lipid, renal function, levels of plasma fructosamine, c-peptide and insulin were determined, and the myocardium of the left ventricular were histologically examined under optical and electron microscope. Results The levels of plasma glucose and lipid of DT group were significantly lower than NC group (P<0.05), and the renal function was maintained on normal level in DT group. The results of determinations were similar between DR group and DT groups, except the level of glyceryl ester. No difference was found in the ratio of heart weight/body weight between DT, DC and DR groups, and no difference was found in the level of c-peptide between DT and DC groups (P>0.05). There was no difference in the level of plasma insulin between DT and NC group (P>0.05). The pathological change in myocardial ultrastructure was markedly milder in DM rats. Conclusion Metformin may exert a certain protective effect on cardiomyopathy of diabetes in rats.