P38MAPK/iNOS信号通路对肾脏缺血预处理的延迟保护效应

目的 探讨P38MAPK与iNOS在肾脏缺血预处理时两者的上下游关系,旨在阐明肾脏缺血预处理延迟保护的可能机制. 方法 雄性Wistar大鼠60只,随机分为五组,每组12只大鼠,分别为:假手术(sham)组,缺血再灌注(IR)组,缺血预处理 缺血再灌注(IPC)组,SB203580药物干预(SB203580)组,氨基胍(AG)药物干预组,各组按再灌注24 h,48 h两时间点又分为两亚组,每组6只大鼠.用苦味酸法测定血清肌酐来反映肾功能变化情况;用HE法观察肾组织形态;用Western blot法检测肾组织P38MAPK与iNOS蛋白的表达,并用图像分析仪进行半定量分析. 结果 血肌酐在IPC组较IR组低(P＜0.05),尤在IPC后48 h明显(P＜0.01);P38MAPK与iNOS表达在sham组,IR组,IPC组三组之间比较有统计学差异,尤在IPC组表达明显(P＜0.01);在SB203580组无P38MAPK蛋白的表达,iNOS的表达较IPC组低(P＜0.05);在AG组无iNOS蛋白表达,P38MAPK蛋白表达与IPC组相差不明显(P＞0.05). 结论 P38MAPK作为iNOS的上游物质参与了肾脏缺血预处理的部分延迟保护效应.

Role of P38MAPK/iNOS signal-transduction-cascades in the delay protection of renal ischemic preconditioning

Objective To explore the relationship between P38 mitogen-activated protein kinase(P38MAPK) and inducible nitric oxide synthase(iNOS) in rat kidney during the late phase of ischemic preconditioning(IPC),and to clarify the possible mechanism of the delay protection in renal ischemic preconditioning.MethodsSixty male Wistar rats were randomly divided into 5 groups: sham operation group(n=12),ischemic reperfusion(IR,n=12) group,ischemic preconditioning ischemic reperfusion(IPC,n=12) group,SB203580(inhibitor of P38MAPK) treated group(SB203580,n=12),AG(inhibitor of iNOS) treated group(AG,n=12).Each group was subdivided into two groups(n=6 in each subgroup) after 24 h and 48 h ischemic reperfusion,respectively.The renal function was examined by measuring serum creatinine.Changes of the renal pathological morphology was observed by hematoxylin-eosine(HE)staining.The expression of P38MAPK and iNOS protein in renal tissues was assayed by Western blotting.ResultsThe values of serum creatinine were lower in IPC group than IR group(P<0.05),and reached the lowest at 48 h(P<0.01).The expression of P38MAPK and iNOS protein was observed in sham operation group,IR group and IPC group,and significantly increased at 48 h in IPC group(P<0.01),while there was no P38MAPK expression in SB203580 group,and lower iNOS expression than in IPC group(P<0.05).In AG group,iNOS protein was not found.P38MAPK expression had no significant difference between AG group and IPC group(P>0.05).ConclusionP38MAPK and iNOS proteins are both involved in the delay renal protection of IPC,and P38MAPK may be a up stream substance of iNOS protein.