Abstract: ［Abstract］ Objective〖HTSS〗〓To observe the expression of extracellular superoxide dismutases(ECSOD) in renal ischemia reperfusion injury(RIRI) rats and to investigate the role of ECSOD in the brain oxidative stress response.
〖HTH〗〖WTHZ〗Methods〖HTSS〗〓The male Wistar rat were divided randomly into RIRI group and control group ，6 rats in each group. After the right kidney was removed in RIRI rats, the left renal artery was clamped with a non injured artery clamp. After 45 min, the rats were removed and the blood supply was restored. After 24 hours of reperfusion, the blood, kidney and brain were taken. The left renal artery were only separated, but not cliped in the control group rats. The urea nitrogen(BUN) and serum creatinine(SCr) in the serum blood of two groups were detected by picric acid method and enzyme coupling rate method. The malondialdehyde（MDA）content in the brain tissue of two groups was determined by thiobarbituric acid colorimetric method. the renal morphological change was observed by HE staining. The ECSOD mRNA and protein expression in brain were evaluated by reverse transcription polymerase chain reaction and western blot.
〖HTH〗〖WTHZ〗Results〖HTSS〗〓Compared with the control group, the BUN and SCr in serum of RIRI group were significantly increased. The content of MDA, H2O2, the relative expression level of ECSOD and the relative expression level of ECSOD protein in RIRI group were higher than those in control group. The difference was statistically significant(P＜005). The content of MDA and H2O2 was positively correlated with the expression of ECSOD mRNA and protein in the brain tissue of RIRI group.
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗〓After the RIRI, oxidative damage in the brain was occured. The increase of ECSOD expression in the brain of RIRI rats may play an important role in anti oxidative stress.

Key words: reperfusion injury, superoxide dismutase; , malondialdehyde