抗坏血酸对糖尿病肾脏足细胞的作用及机制探讨  

STUDY ON THE EFFECT AND MECHANISM OF ASCORBIC ACID ON RENAL PODOCYTES IN DIABETES

作　　者：覃乔静[1] 邓华聪[2] 赵同峰[1] 曹文富[2] 刘东方[2] 兰丽珍[2] 

机构地区：[1]浙江大学医学院附属第二医院,浙江杭州310009 [2]重庆医科大学附属第一医院,重庆400016

出　　处：《中国应用生理学杂志》2008年第1期112-115,I0003,共5页Chinese Journal of Applied Physiology

摘　　要：目的:研究抗坏血酸对糖尿病大鼠肾小球滤过屏障最外层足细胞的作用,并探讨其可能的作用机制。方法:采用腹腔注射链脲佐菌素建立糖尿病大鼠模型,经抗坏血酸治疗5周后,测定血糖(BG)、糖化血红蛋白(HbA1c)、24 h尿白蛋白排泄率(UAER)、肾皮质超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和丙二醛(MDA)水平,并观察足细胞超微结构,检测足细胞损伤标志-desmin蛋白的表达。结果:与正常对照组大鼠比较,糖尿病组大鼠血BG、HbA1c显著增高,肾皮质SOD、CAT活性显著降低,MDA含量、肾小球内desmin蛋白表达明显增加,足细胞足突融合显著,UAER显著升高(均P<0.05);与糖尿病组大鼠比较,在血BG、HbA1c无明显差异条件下(均P>0.05),抗坏血酸可明显增加糖尿病大鼠肾皮质SOD活性,降低肾皮质MDA含量和desmin蛋白表达水平,并显著减轻足细胞足突融合,减少UAER(均P<0.05),肾皮质CAT活性虽有一定程度增高但差异无显著性(P>0.05)。结论:糖尿病大鼠肾小球滤过屏障最外层足细胞有明显损害,补充抗坏血酸对足细胞起保护作用,其机制可能与增强肾脏抗氧化能力,减轻肾脏氧化应激有关。Aim： To investigate the effect and mechanism of ascorbic acid on podocyte, last barrier of glomerular filtration, in diabetic rats. Methods： Diabetic rats induced by streptozotocin injection intraperitoneally were treated by ascorbic acid for 5 weeks. The levels of blood glucose（BG）, HbAlc, urinary albumin excretion rate（UAER） and superoxide diamutase（SOD）, catalase （CAT） and malondialdehyde （MDA） in renal cortex were measured. The podocyte ultrastructure was observed while the expression of desmin protein, a marker of podocyte injury, was examined. Results： Compared with control group, BG and HbAlc were increased markedly in diabetic group. The activities of SOD and CAT were decreased and the concentrations of MDA were increased significantly in diabetic renal cortex. There were the increased proteinic expression of desmin, foot process effacement in podocytes and UAER markedly in diabetic rats. Compared with diabetic rats, foot process effacement and the changes of UAER were ameliorated markedly while the activities of SOD were increased, the levels of MDA and proteinic expression of desmin were decreased markedly although BG, HbAlc and the activities of CAT were no significant difference in the diabetic rats by ascorbic acid treatment. Conclusion： The findings suggest that there are marked injury in podocyte, last barrier of glomerular filtration, in diabetic rats and administration of ascorbic acid can protect podocyte by increasing antioxidative capacity and ameliorating the renal oxidative stress.

关 键 词：抗坏血酸 糖尿病 肾小球滤过屏障 足细胞 氧化应激 

分 类 号：R587.1[医药卫生—内分泌]