缺血预处理对大鼠肝细胞凋亡及HIF-1α和Survivin蛋白表达的影响

目的：观察缺血预处理（IP）对缺血再灌注（IR）损伤引起的肝细胞凋亡及对调控基因Survivin、HIF-1α蛋白表达的影响,探讨IP对鼠肝IR损伤保护作用的机制。方法：将90只SD大鼠分为假手术（SO）组10只、IR组和IP组各40只。SO组术中只牵拉分离肝十二指肠韧带,操作完成后关腹;IR组阻断十二指肠韧带,造成缺血30min;IP组缺血30min前持续5min缺血及5min再灌注。IR组及IP组分别于再灌注2、6、12和24h后各处死10只动物,取肝脏标本;SO组于术后2h取肝组织标本。检测细胞凋亡指数（AI）及Survivin、HIF-1α蛋白表达水平。结果：IR组、IP组AI较SO组明显增加（P〈0.05）,相同时相点IP组较IR组细胞AI明显降低（P〈0.05）。IR组、IP组Survivin、HIF-1α蛋白表达先升后降,6h左右达高峰;HIF-1α（除24h时）和Survivin蛋白表达在相同时相点IP组较IR组高（P〈0.05）。结论：IP对肝组织IR损伤的保护作用机制之一可能是通过上调HIF-1α、Survivin蛋白的表达抑制细胞凋亡,从而发挥肝脏保护作用。

Effect of ischemic preconditioning on the apoptosis of hepatocytesand expression of HIF-1α and Survivin in rats

Objective：To observe the effect of ischemic preconditioning（IP）on hepatocellular apoptosis caused by ischemia-reperfus ion（IR）injury and expression of apoptosis regulatory genes（Survivin,HIF-1α）protein,to explore the protective mechanisms of IP on IR injury in rat liver.Methods：Ninty SD rats were randomly divided into sham operation（SO）group,ischemia-reperfusion（IR）group,ischemic preconditioning（IP）group.In SO group,the hepatoduodenal ligament of rat was only pulled and separated,and then closed the abdomen;IR group subjected to 30 minutes of ischemia;IP group was achieved by ischemia for 5 minutes,followed by reperfusion for 5 minutes before continuous to ischemia for 30 minutes.Ten rats of each group were killed after reperfusion for 2,6,12,24 hours respectively,then liver tissues were taken out.The rats in SO group were killed after operation for 2 hours.To detect the Apotosis index（A）Iand Survivin,HIF-1α protein levels.Results：AI of hepotocytes significantly increased in IR group and IP group than that in SO group（P〈0.05）,in the same point,cells AI of IP group compared with IR group was significantly lower（P〈0.05）.The expression of Survivin,HIF-1α protein in IR group and IP group in first increased and then decreased with time,6 hours and peaked around;in the same point,the expression of Survivin,HIF-1αprotein in IP group higher than that in IR group,the difference was statistically significant（P〈0.05）.Conclusion：one of the protective mechanisms of ischemic preconditioning on hepatic ischemia-reperfusion injury in rats may inhibit cell apoptosis by up-regulating HIF-1α,survivin protein expression.