The Protective Effects Of Gastric Bypass On Kidney Injury And To Discuss Its Possible Mechanisms In Type2Diabetic Rats

Objective:To observe the protective effects of gastric bypass onkidney injury and discuss its possible mechanisms in type2diabeticrats.Methods:Forty SD rats were randomly divided into normal control group（n=8），diabetes model group（n=32），the diabetes model group were injectedSTZ（35mg/kg），when the blood glucose steady，there were30rats wereconsidered as the the successful diabetes model.Then they were randomlydivided into diabetes control group(n=8),diabetes sham operation group(n=8)and diabetes operation group(n=14).Rats in diabetes operation group underwentRoux-en-Y gastric bypass operation while rats in diabetes sham operation groupunderwent antroduodenal transaction and then,reanastomosis in situ.thekidney hypertrophy index （kidney weight/body weight）， fasting bloodglucose(FBG), blood urea nitrogen(BUN),serum creatinine(Cr),the activitiesof total superoxide dismutase（TSOD）and glutathione peroxidase（GSH-PX），content of malondialdehyde（MDA），activity of aldose reductase（AR）andARmRNA expression, activity of protein kinase C（PKC)in kidney weremeasured after operation for8weeks.at the same time,the expressions ofTGF-βI， COI-Ⅳ and FN in the kidney were detected byimmunohistochemistry.In addition,the renal tissue was observed by lightmicroscopy.Results:Kidney hypertrophy index， FBG,BUN,Cr,content ofMDA，activities of AR、PKC and ARmRNA expression,the expressions of TGF-βI，COI-Ⅳ and FN in kidney significantly increased，while the activitiesof TSOD and GSH-PX decreased in diabetes control group and diabetes shamoperation group compared with normal control group（P<0.05）.In diabetesoperation group，kidney hypertrophy index，FBG,BUN,Cr, content of MDA，activities of AR、PKC and ARmRNA expression,the expressions of TGF-βI，COI-Ⅳ and FN in kidney markedly decreased（P<0.05）,the activities of TSODand GSH-PX increased（P<0.05）compared with diabetes control group anddiabetes sham operation group.Renal pathologic changes in diabetes operationgroup were also improved. Conclusion:The damage of structure and function ofdiabetic kidney are closely related to kidney oxidative stress, increased of ARactivity and ARmRNA expression, PKC activity, content of TGF-β1andexcessive accumulation of extracellular matrix COI-Ⅳ and FN.The gastricbypass could protect the kidneyt of type2diabetic rats which may be ascribedto reduction of oxidative stress and inhibition of polyol pathway in renal tissuementioned above.