瘦素在2型糖尿病大鼠肾脏病变发生发展中作用的探索

目的探讨瘦素(leptin)在糖尿病肾脏病(DN)变发生发展中的作用。方法雄性Wistar大鼠70只,随机分为实验组和对照组,实验组40只,喂以高热量饲料2个月后,腹腔注射链脲佐菌素(STZ)30mg/kg;对照组30只,喂以普通饲料2个月后,腹腔注射等体积的枸橼酸缓冲液。两组分别于注射前、注射后1、2、3和6个月各处死6只,取血测定血清瘦素、胰岛素水平等,光镜电镜观察肾脏形态学改变。结果成模后1月后肾小球体积开始增大,2月更明显,3月及6月体积显著下降;成模后2月出现明显蛋白尿,肾小球基底膜3月时就已显著增厚,6月时更为严重;瘦素水平在高热量饮食2月后即较对照组显著增高(P<0.01),在注射STZ后1个月时由于体重的下降而较前有所下降,但仍高于对照组(P<0.01),以后随着病程的进展呈逐渐升高趋势。结论进一步证明瘦素可能是促进糖尿病肾脏病变的发生、发展的因素之一。

Role of Leptin in Diabetic Nephropathy of Rats

Objective To study the relationship between leptin and diabetic nephropathy(DN).Methods Seventy Wistar rats were randomly divided into two groups:30 in the normal control(NC)group and 40 in the diabetic mellitus(DM)group.The rats in DM group were injected intraperitoneally with low dose streptozotocin(STZ,30mg/kg)after 2-month fed with high calorie diet,while the animals of NC group were injected intraperitoneally with the same volume citric acid buffer after 2-month normal diet.Before and after treatment 1,2,3 and 6 months,6 rats in each group were sacrificed and blood samples were obtained to measure the levels of leptin,fasting blood insulin(FINS),cholesterol(Cho),triglyceride(Tri),etc.The kidney samples were used for analyzing morphologically.Results Volume of glomerule of DM group was bigger than NC group at month one after injection with STZ(P<0.01).The difference was more significant at month two.However,the volume of glomerule of DM group was smaller than NC group at months 3 and 6(P<0.01).Glomerular basement membrane(GBM)was thicker in DM group than in NC group at months 3 and 6(P<0.01);the level of leptin of DM group was much higher than NC group after high calorie diet given for two months(P<0.01),but decreased after injected with STZ,then it increased continually during the whole experiment.Conclusion leptin may be one of the facilitative facts in the pathogenesis of DN.