预处理对肝再灌注损伤大鼠肝组织中诱生性一氧化氮合酶mRNA表达及血浆NO/ET-1水平的影响

目的 研究肝缺血预处理(IPC)对肝再灌注损伤大鼠肝组织诱生性一氧化氮合酶(iNOS)mRNA表达和NO／ET-1水平的影响及IPC最适时间。方法 采用大鼠肝缺血-再灌注损伤(I／R)模型，分别观察正常对照组、缺血-再灌注损伤组(I40min／R60min组)、预处理1组(IPC5min／10min I40min／R60min组)、预处理2组(IPC10min／10min I40min／R60min组)、预处理3组(IPC15min／10min I40min／R60min组)的NO/ET-1水平，采用RT-PCR法检测iNOSmRNA的表达。结果 缺血-再灌注损伤组NO／ET-1水平显著降低，而iNOSmRNA高表达；预处理各组NO／ET-1水平均上升，iNOSmRNA均下调，尤以预处理3组最明显。结论 IPC对I／R肝的保护作用可能与NO／ET-1水平的升高及iNOSmRNA表达水平的下调有关，IPC最适时间为15min／10min。

Effect of ischemic preconditioning in rats hepatic I/R model on the NO/ET-1 system in plasma and the expression of iNOS mRNA

Objective To study the effects of the hepatic ischemic preconditioning (IPC) on the NO/ET?1 system and the expression of iNOS mRNA,as well as the optimum time by IPC.Methods The changes of NO/ET?1 in blood plasma were compared between I 40min/R?60?min group and IPC(5?min/10?min,10?min/10?min,15?min/10?min) +I?40?min/R?60?min groups in rats hepatic I/R model.At the same time,the liver tissues were detected by RT?PCR to screen the iNOS mRNA level.Results The ratio of NO/ET?1 was reduced markedly in I/R group,while the expression of iNOS mRNA was increased.The ratio of NO/ET?1 was increased gradually with the extended ischemic preconditioning time in IPC+I/R groups and reached its peak level in IPC(15?min/10?min)+I?40?min/R?60?min group,while the expression of iNOS mRNA was decreased gradually with a maximum effect in IPC(15?min/10?min)+I?40?min/R?60?min group.Conclusions The protection of IPC to the hepatic I/R injury is probably related to the increased ratio of NO/ET-1 and the decreased expression of iNOS mRNA.The optimum time of IPC is 15min/10min.