Different Density Of Sevoflurane Postconditioning On Renal Ischemia-reperfusion Injury In Rat In Vivo

Background Renal ischemia-reperfusion injury in clinical practice was commonly seen,such as shock,transplant,bypass,and so on.How to reduce these injuries was becoming a hot topic in academic circles.In early days,sevoflurane was considered harmful to kidney, but today these ideas were proved wrong.There were not enough proofs to show toxicity on kidney in human.Sevoflurane was used widely for anesthesia.it has reported that sevoflurane can mitigate ischemia-reperfusion injury of heart,lung,liver and brain,but papers about it affected kidney was limited reported.After renel reperfusion injury,the expression of renal NO synthase(endothelial,eNOS and induible,iNOS)was enhanced.The expression of eNOS secreted NO,which can protect kidney from injury named direct effect.The expression of iNOS produced NO,which can hurt kidney named indirect effect.But the effect of sevoflurne on renal NO synthase after reperfusion-injury in kidney was not reported.Objective To investigate the protective effects of different density of sevoflurane postconditioning on reperfusion injury after renal ischemia in rat.To determine the effects of sevoflurane postconditioning on the expression of eNOS iNOS in kidney after renal ischemia-reperfusion injury(I/R).Methods In a right-nephrectomized rat model,sixty male SD rats weighing 220-250g were randomly divided into 5 groups with 12 animals in each group:groupⅠsham operation (S);groupⅡI/R;groupⅢ(1.2%),Ⅳ(1.8%),andⅤ(2.2%)sevoflurane postconditioning, sevoflurane was inbreathed during the first 2h of reperfusion.After right nephrectomized,renal I/R was produced by occlussion of left renal arteries and veins with atraumatic clamps for 45min,then the clamps were removed for 24h reperfusion.The animals were killed at the end of 24h reperfusion.Blood samples were taken for determination of blood creatinine(Cr),blood urea nitrogen(BUN).And the left kidney was harvested for assessing the percent of pyknotic nuclei in cortical tubular cells.eNOS and iNOS expression in kidney on groupⅠ,ⅡandⅣwas detected immunohistomically.Result(1)As compared with groupⅠ,serious congestion,obvious grey area(include most of necrosis cell)in outer medullary stripe can be observed by eyes in groupⅡ～Ⅴ;As compared with groupⅡ,the phenomenon of congestion and grey area in groupⅢ～Ⅴwas mitigated,but there was no difference among groupⅢ,groupⅣand groupⅤ.(2)As compared with groupⅠ,blood Cr,BUN was significantly increased in groupⅡ,Ⅲ,ⅣandⅤ(P＜0.05);And as compared with groupⅡ,these indexes listed above were significantly decreased in groupⅢ,ⅣandⅤ(P＜0.05).These indexes were not showed apparent differences among groupⅢ,ⅣandⅤ(P＞0.05).(3)As compared with groupⅠ,the percent of pyknotic nuclei in cortical tuber cells were significantly increased in groupⅡ,Ⅲ,ⅣandⅤ(P＜0.05);And as compared with groupⅡ,these index listed above were significantly decreased in groupⅢ,ⅣandⅤ(P＜0.05).These indexes were not showed apparent differences among groupⅢ,ⅣandⅤ(P＞0.05).(4)As compared with groupⅠ,eNOS,iNOS expression in kidney was significantly increased in groupⅡ(P＜0.05);And as compared with groupⅡ,eNOS,iNOS expression in kidney was significantly decreased in groupⅣ(P＜0.05).But it is no apparent differences between groupⅠand groupⅣ(P＞0.05).Conclusion(1)sevoflurane postconditioning can attenuate renal ischemia-reperfusion injury in rat in vivo;(2)Different density was not showed different effects;(3)The protective effects made by sevoflurane were achieved by down-regulating eNOS and iNOS expression in kidney.