The Effects Of Oxidative Stress And The Expressions Of TGF-β₁ In Cortex Of Kidney Of Diabetic Rats By Use Of Pioglitazone

Objective:To study the effects of oxidative stress and the expressions of TGF-β1 in cortex of kidney of diabetic rats by use of Pioglitazone;To investigate the diabetic rats kidney-protective effects of use of Pioglitazone.Methods:Thirty-two male Wistar rats were randomly divided into four groups:normal control rats(NC group);diabetic rats(DM group);diabetic rats treated with small dose Pioglitazone(D1 group,Pioglitazone 3mg/kg/d);diabetic rats treated with big dose Pioglitazone(D2 group,Pioglitazone 9mg/kg/d)(n=8).Hyperglycemia was induced with streptozotocin in rats of DM group,D1 group and D2 group.After 12 weeks,blood glucose,blood fat(CHO,LDL,HDL,TG),blood urea nitrogen(BUN),serum creatinine(Scr),blood insulin,blood C-peptide,UAER,kidney weight/body weight ratio were measured.The levels of malondialdehyde(MDA)in renal tissue as well as activities of Cu,Zn superoxide dismutase (Cu,Zn-SOD),catalase(CAT)in renal tissue were determined.Expressions of TGF-β₁ of glomeruli were detected by immunohistochemichal staining.Correlation between Cu,Zn-SOD,CAT,MDA and TGF-β₁ were analysised.Results:1,The kidney weight/body weight ratio,UAER,expressions of TGF-β₁,the levels of MDA of DM rats were significantly higher than that of NC rats;The activities of Cu,Zn-SOD,CAT of DM rats were significantly lower than that of NC rats,(P<0.05,P<0.01).2,The kidney weight/body weight ratio,UAER,expressions of TGF-β₁,levels of MDA of all treated rats were lower than DM rats;The activities of Cu,Zn-SOD,CAT of all treated rats were higher than DM rats;Compare the paraments of D1 and D2 group,D2 group changed more obviously than D1 group,(P<0.05,P<0.01).3,The blood glucose,CHO,LDL,TG,blood urea nitrogen(BUN),serum creatinine(Scr) of DM,D1 and D2 group were significantly higher than NC group;blood insulin,blood C-peptide,HDL of DM,D1 and D2 group were significantly lower than NC group,(P<0.05).4,Compare the blood glucose,blood fat,blood urea nitrogen(BUN),serum creatinine(Scr),blood insulin,blood C-peptide of DM,D1 and D2 group,there were no significant difference, (P>0.05).5,The activities of Cu,Zn-SOD,CAT were positively correlated with the expressions of TGF-β₁;levels of MDA were negatively correlated with the expressions of TGF-β₁,(P<0.05).Conclusion:This study shows that the kidneys of diabetic rats undergo an obvious oxidative st ress.Pioglitazone treatment can probably to some extent protect kidneys from oxidative injury and expression of TGF-β₁ by diabetes,which is independent of its glucose and lipid-reducing effect and dependent of its dose.