Protective Effects Of 17β-Estradiol On The Kidney Of Diabetic Rats

Objective:To explore the protective effects of 17β-estradiol on ren- al morphology and renal function of rats with streptozotocin diabetes.Methods:The adult female Sprague-Dawley rats were separated into three groups:Normal control group(NC),Diabetes group(DM),17β-estradi- ol group(E2). To induce an experiment model of diabetes,rats received a si- ngle intraperitioneal injection of STZ. E2 group received 17β-estradiol 1mg /kg/d by hypodermic injection.12 weeks after STZ injection,the following determination were done in samples:(1).Observe body weight(BW),kidney weight(KW), kidney/body weight ratio(KW/BW), 24h urinary protein excr- etory(24hUPE),serum creatinine(Scr),blood urea nitrogen(BUN) and the changes of pathologic feathure of the kidney; (2).Evaluate the level of Nitr- ic Oxide(NO) in cortex of kidney;(3). By immunohistochemistry staining, observe the expression of of the Angiotension II type-2 receptor(AT-2R), Transforming growth factor-1(TGF-β1),endothelial nitric oxide synthase(e- NOS),inducible nitric oxide synthase(iNOS) of kidney tissue section;(4).By RT-PCR, observe the expression of AT-2R, TGF-β1, eNOS, iNOS mRNA of the kidney tissue.Results:(1)BW,KW,KW/BWratio,MGV,FMA,Scr,BUN,24hUPE and the expression of TGF-β1,iNOS were significantly increased in DM group than those in NC group(P<0.01);the level of NO in kidney cortex and the expression of AT-2R,eNOS were all obviously lower than those in normal rats(P<0.01). (2) All these abnormalities were markedly ameliorated when hypodermic injected with 17β-estradiol(P<0.05)as well as the renal pathol- oic lesions such as podocyte foot process fuse and GBM thickening were attenuated.Conclusion:Mechanism of reno-protection of 17β-Estradiol may be at least partly correlated with inhibit the expression of of TGF-β1,iNOS;increase the contents of NO and the express of AT-2R,eNOS.