Protective Effect of Candesartan on Podocyte Damage in Rats with Diabetic Nephropathy

Objective To investigate the changes in podocyte ultrastructure and nephrin expression in rats with diabetic nephropathy(DN),and to observe the effect of candesartan on podocyte damage.Methods Thirty-six Sprague-Dawley rats were randomly divided into normal control group(group A),DN model group(group B),and candesartan treatment group(group C),with 12 rats in each group.DN was induced by intravenous injection of streptozotocin(30 mg·kg-1) and rats in group C were intragastricly given candesartan(5 mg·kg-1·d-1) 1 week after induction of DN.Rats in group A and group B were given the same amount of normal saline.Blood glucose levels,body weight,24-hour urinary protein excretion and endogenous creatinine clearance(Ccr) were measured at 4 and 7 weeks after treatment.Pathological changes in renal tissues were evaluated by HE staining and podocyte ultrastructure was observed using electron microscop.The expression of nephrin was detected by RT-PCR.Results Compared with group A,24-hour urinary protein excretion and serum creatinine increased,Ccr decreased at 7 weeks,and nephrin expression reduced in group B(all P0.05).Compared with group B,24-hour urinary protein excretion,serum creatinine,foot process width and glomerular basement membrane thickness decreased,and Ccr and nephrin expression increased in group C(all P0.05).Conclusion DN patients have abnormal podocyte ultrastructure and nephrin expression.Candesartan can protect podocyte damage through up-regulating nephrin expression and improving podocyte ultrastructure.