The expression of Podocin in glomerular podocytes of obesity rats and its significance / 中华内分泌外科杂志

ABSTRACT

Objective To discuss the mechanism of obesity related glomerularpathology,we detect the expression of Podocin in glomerular podocytes of obesity rats induced by high fat diet.Methods The rats were divided into 2 groupsnormal control group(Con group) and obesity group(Ob group).At the 14th week of molding,the body weight,body long,tail long,kidney weight,uria microalbumin,RBP,uria Cre,blood glucose,cholesterol,triglyceride,HDL-C,UA,Cre,BUN,and insulin were measured.The Lee's index,insulin resistance index,insulin sensitive index,Ccr and relative kidney weight were calculated.The tissue structures of the kidney of both groups were studied under light microscope and transmission electro microscope.The expression of Podocin in podocyte of rats' kidney was measured by immunohistochemistry and western blot.Results ①The difference had no statistical significance between the 2 groups in gender,weight,body length,tail length and Lee's index at the beginning (P ＞ 0.05).But after 14 weeks,the weight,body length and Lee's index of Ob group were significantly higher than those of Con group(P ＜0.05).②At the 14th week,the fasting plasma glucose of Ob group was higher than that of Con group (P ＜ 0.05),and the high density lipoproteins (HDL) of Ob group was lower than that of Con group(P ＜ 0.05).However,the difference had no statistical significance in urine acid (UA),serum Cre and blood urea nitrogen (BUN) between the 2 groups (P ＞ 0.05).③The urine protein and endogenous creatinine clearance rate(Ccr) in Ob group were higher than those of Con group (P ＜ 0.05,P ＜0.01).④The relative kidney weight of Ob group was lower than that of Con group(P ＜ 0.05).⑤For rats in Ob group,glomerular hypertrophy,the Bowman' capsule stricture,abnormality in the segmental capillary wall and extraglomerular mesangial cell were observed under light microscope.The glomerular podocytes became broader and foot process of podocyte in Ob group became microvillus-like in Ob group under transmission electro microscope.⑥Immunohistochemistry and western blot showed that the expression of Podocin in podocyte of kidney decreased in Ob group.Conclusions The expression of Podocin decreased in podocyte of kidney in obesity rats.At the same time,the ultrastructure of podocytes was changed.Those may be one of the reasons for protein urine related to obesity.