细胞凋亡和Bcl-2、Bax基因在兔肺缺血再灌注损伤中的作用

目的:探讨细胞凋亡在兔肺缺血再灌注损伤中的作用以及Bcl-2和Bax基因的调控.方法:健康日本大耳白兔48只,随机分为对照组与肺缺血再灌注损伤1 h、3 h和5 h组.复制在体肺缺血再灌注损伤模型.采用TUNEL法观测肺组织细胞凋亡;予免疫组化及原位杂交技术检测肺组织细胞Bcl-2、Bax蛋白和基因表达.结果:随着再灌注时间的延长,凋亡指数(AI)及Bax蛋白、BaxmRNA水平进行性升高;Bcl-2蛋白及Bcl-2mRNA先升高而后下降(均P＜0.01).凋亡指数(AI)与Bax蛋白及Bax mRNA之间均呈显著正相关(r分别=0.926,0.933;均P＜0.01),而与Bcl-2蛋白/Bax蛋白及Bcl-2mRNA/BaxmRNA的比值呈显著负相关(r分别=-0.836,-0.879;均P＜0.01).结论:肺组织细胞凋亡参与了肺缺血再灌注损伤的发生,Bcl-2/Bax的比值下降是促进凋亡的重要因素.

Role of apoptosis and Bcl-2,Bax gene in rabbits with lung ischemia reperfusion injury

Objective: To evaluate the effects of apoptosis and expression of apoptotic related genes on lung tissues of rabbits after lung ischemia reperfusion. Methods: Single lung in situ ischemia reperfusion animal model was used. 48 rabbits were randomly divided into four groups: control group(C), ischemia reperfusion 1h group(IR1h), ischemia reperfusion 3h group (IR3h) and ischemia reperfusion 5h group (IR5h). By using TUNEL, immunocytochemistry and in situ hybridization (ISH) techniques, apoptosis and Bcl-2, Bax mRNA and protein expression were studied in lung tissues of rabbits treating with lung ischemia reperfusion and in control subjects. Results: Increasing of apoposis index(AI)and the expression of Bax gene were discovered during lung ischemia reperfusion injury in rabbits,and the expression of Bcl-2 was increased at the beginning, then declined. There was a significant positive correlation between AI and the expression of Bax (r=0.926,0.933; P< 0.01,respectively),and there was a significant negative correlation between AI and the ratio of Bcl-2 protein/Bax protein.Bcl-2 mRNA/BaxmRNA(r=-0.836,-0.879: P< 0.01,respectively). Conclusion: Apoptosis participates in lung ischemia reperfusion injury. The ratio of Bcl-2/Bax declines gradually,which accelerates the occurrence of apoptosis.