肝动脉缺血对肝细胞凋亡的影响及其机制初探

目的　探讨肝动脉缺血 (HAI)过程中氧自由基对肝细胞凋亡的影响及其机制。方法　将家兔按再灌注后有无HAI分为HAI组和对照组。在兔肝自体原位移植模型基础上 ,应用原位末端标记 (TUNEL)技术、免疫组化法和比色法 ,检测肝细胞凋亡指数 (AI)、bc1 2蛋白表达和肝组织中MDA生成水平。结果　随着HAI时间的出现和延长 ,肝细胞凋亡指数增大。当HAI 3h时 ,HAI组凋亡指数增高为 12 .5 %± 1.38% ,与同组HAI 30min、HAI 2h和对照组的AI值比较均有显著性升高 (P <0 .0 5 )。bc1 2蛋白表达阳性细胞于再灌注后增多 ,但HAI组与对照组比较 ,各时点均无明显差异。同时 ,肝组织内MDA含量逐渐增多 ,HAI组HAI 3h达到最高 ,同组HAI各时点的MDA含量比较均有显著性差异 (P <0 .0 5 )。结论　HAI损伤可通过进一步促进缺血再灌注后氧自由基的生成而加重肝细胞凋亡的发生 ,阻碍供肝功能的恢复 ,是肝移植后供肝功能不全和并发症发生的关键因素之一。

Effects of hepatic artery ischemia on hepatocytic apoptosis and its mechanism

Objective To observe the effects of oxygen derived free radicals on hepatocytic apoptosis during the hepatic artery ischemia (HAI) and investigate the initial mechanism. Methods The rabbits were divided into two groups, group HAI and control, depending on whether or not HAI happened after reperfusion. On the model of orthotopic hepatic autotransplantation in the rabbits, the apoptosis index (AI) of hepatocytes was examined by the in situ end nick labelling technique (TUNEL) and bc1 2 protein expression was detected immunohistochemically and the concentration of MDA in liver tissues applied chromatometry. Results The AI of hepatocytes were increased gradually following the time of HAI prolonged. The AI in group HAI 3 hours, 12.15%±1.38%, was higher than that of HAI 30 minutes, HAI 2 hours and control groups; the bc1 2 positive cell increased after reperfusion and there was no significant difference in all of indices between group HAI and control ( P >0.05);the concentration of MDA in the hepatic tissues increased after reperfusion. The concentration of MDA in HAI 3 h was the highest and there were significant differences between each HAI group ( P <0.05). Conclusion HAI develops the apoptosis of hepatocyte by promoting the production of oxygen derived free radicals and impeding the recovery of hepatic function. HAI might be one of the key factor of hepatic insufficiency and complications following liver transplantation.