Vitamin D alleviates diabetic nephropathy of rats by resisting oxidative stress

AIM To study whether vitamin D inhibits oxidative stress to protect diabetic nephropathy(DN).METHODS The diabetic rats were induced by intraperitoneal injection with streptozotocin.Then,the diabetic rats were fed with rodent chow about 2 months to induce DN.The rats were randomly divided into three groups.The intragastric administration with calcitriol 0.2 μg·kg~(-1)·d~(-1) was applied to DN rats in the calcitriol treatment(DNR) group.The rats in the normal control(NC) group and DN group were only treated with equivalent arachisoil.After 1 month treatment,the body weight of rats,random blood glucose,the level of malondialdehyde(MDA),total superoxide dismutase(T-SOD),total antioxidant capacity(T-AOC),hydrogen peroxidase(CAT) and glutathion peroxidase(GSH-PX) of rats serum in each group were tested.The ultra-structure of rats kidneys was observed with electron microscope.The mRNA expression of glutathion peroxidase 1(GPX1),superoxide dismutase 1 and 2(SOD1,SOD2) of kidneys were detected by means of real-time PCR.RESULTS Compared with NC group,the body weight of rats was decreased in the group DN and DNR,but serum glucose and triglyceride were increased significantly(P 0.05 or P 0.01).The kidney weight to body weight ratio and UA/Cr in the group DN were more elevated than those of group NC and DNR(P 0.05 or P 0.01).Compared with group NC,the serum MDA in the group DN was higher and the activity of serum T-SOD,T-AOC,CAT,GSH-PX and the renal mRNA expression of GPX1,SOD2 and SOD1 were reduced(P 0.01).In the meantime,the ultra-structure of rats kidneys showed obviously abnormal changes in the group DN.Compared with group DN,the MDA in the group DNR was reduced obviously,while the activity of serum T-SOD,T-AOC,CAT,GSH-PX and the renal mRNA expression of GPX1,SOD2 and SOD1 in group DNR were increased(P 0.05 or P 0.01).As a result,the renal ultra-structure improved predominantly.CONCLUSION Vitamin D can improve DN of rats significantly.This protective effect might be related to alleviate oxidative stress of rats by raising anti-oxidant ability of kidney.