缺血预处理对肝缺血再灌注时细胞凋亡及调控基因表达的影响

Effect of ischemic preconditioning on the apoptosis of hepatocytes and expression of regulating gene in hepatic ischemic reperfusion

目的探讨缺血预处理对肝脏细胞凋亡的影响以及与调控基因bcl-2/bax蛋白表达的关系。方法将家兔分为假手术(SO)组、缺血再灌注(IR)组,缺血预处理(IP)组。后2组中再分为4个亚组(IR3h、12h、24h和48h组,IP3h、12h、24h和48h组)。缺血期均为60min。缺血预处理为缺血前采用5min缺血及5min再灌注的方法。分别于再灌注3、12、24和48h后处死动物采取肝脏标本,SO组于手术后24h采取肝标本。检测细胞凋亡及bc1-2/bax蛋白表达水平。结果IR组和IP组与SO组比较,细胞凋亡指数(AI)增加差异有显著性(P<0.01);IP组中IP3h、12h和24h较同时间段IR组细胞凋亡指数降低差异有显著性(P<0.05);bcl-2蛋白表达:IP组与IR组及SO组比较,增高差异有显著性(P<0.05);bax蛋白表达:IR组和IP组与SO组比较增加差异有显著性(P<0.05)。结论缺血预处理可能通过激活bcl-2蛋白的表达,改变bcl-2/bax表达比例从而抑制肝细胞凋亡。

[Objective] To explore whether hepatocellular ischemia reperfusion OR） injury elicites the apoptosis of hepatocytes or ischemic preconditioning （IP） reduces the apoptosis （AP） of hepatocytes due to IR injury in the rabbits, and the effect of IP on AP regulating genes bel-2/bax protein expression. [Methods] The rabbits were randomly divided into sham-operation （SO） group, IR group and IP group. The latter two groups were futherly divided into 4 subgroups respectively and subjected to 60 min before continuous block of the liver inflow. And we choose 5 min ischemia and 5 min reperfusion as the pattern of ischemic preconditioning. The rabbits were killed after reperfusion for 3, 12, 24 and 48 h respectively, then liver tissues were sampled to examine the apoptosis and bel-2 and bax proteins. In SO groups the rabbits rats were killed 24 h after the operation and the liver tissues were sampled. [Results] Apotosis index of hepotocytes signficantly increased in IR groups and IP groups than that in SO group （P 〈0.01）, and was significantly elevated in IR-3 h, 12 h, 24 h, groups compared with that in IP 3 h, 12 h, 24 h groups （P 〈0.05）. The expression of bel-2 protein was significantly increased in IR groups than that in SO group and IP groups （P 〈0.05）. Expression of bax protein was significantly increased in IR group and IP group than that in SO group （P 〈0.01）. [Conclusions] This study shows that： IP may decrease the apoptosis of hepatocytes by increasing bel-2 gene expression.