缺血预适应对再灌注性心肌细胞凋亡及其Bcl-2和Bax蛋白表达的影响  

Effects of ischemic preconditioning on myocardial cell apoptosis and expression of Bcl-2 and Bax protein during cardiopulmonary bypass

作　　者：何斌[1] 王志农[1] 曾志勇[1] 徐志云[1] 黄盛东[1] 朱泉芳[1] 张宝仁[1] 

机构地区：[1]第二军医大学长海医院胸心外科,解放军胸心外科研究所上海200433

出　　处：《第二军医大学学报》2004年第4期379-382,共4页Academic Journal of Second Military Medical University

基　　金：上海市曙光计划资助项目 ( 0 2 SG3 0 ) ;上海市青年科技启明星计划资助项目 ( 0 0 QB14 0 5 3 )

摘　　要：目的 :研究体外循环 (CPB)中缺血预适应 (IPC)对心肌细胞凋亡及其 Bcl- 2和 Bax蛋白表达的影响。 方法 :建立猫CPB模型并随机均分成 3组 :对照组 (n=30 )不阻断升主动脉 (ACC) ,仅作 CPB转流 ;缺血再灌注组 (IR组 ,n=30 )于 CPB开始 4 5 min后 ACC6 0 m in,开放主动脉使心脏恢复再灌注 ;IPC组 (n=30 )于 ACC前进行 IPC(ACC5 min后开放 1 0 min,并重复 3次 ) ,余同 IR组。应用 TUNEL 法观察 CPB过程中各组心肌细胞凋亡发生的情况 ,应用免疫组化 SABC法观察 Bcl- 2和Bax蛋白的表达 ,并结合流式细胞术定量检测心肌细胞凋亡率和 Bcl- 2、Bax蛋白的表达率。 结果 :各组在 CPB缺血期间及再灌注早期 ,均未检出凋亡心肌细胞 ;IR组和 IPC组在心肌再灌注 90 m in时 ,可检测到一定数量的凋亡心肌细胞 ,凋亡率分别为 (6 .932± 0 .6 38) %和 (3.0 2 1± 0 .2 5 4 ) % ,组间差异显著 (P<0 .0 5 ) ;与对照组相比 ,IR组的 Bcl- 2蛋白表达阳性率明显下降(P<0 .0 5 ) ,Bax蛋白表达阳性率则明显上升 (P<0 .0 5 ) ;而 IPC组的 Bcl- 2蛋白表达阳性率高于 IR组 (P<0 .0 5 ) ,Bax蛋白表达阳性率低于 IR组 (P<0 .0 5 )。 结论 :CPB中缺血再灌注可影响心肌细胞凋亡相关基因 Bcl- 2和 Bax蛋白的表达水平 ;IPC可以通过上调 Bcl- 2?Objective:To elucidate the effects of ischemic preconditioning (IPC) on the myocardial cell apoptosis and expression of apoptosis related genes (Bcl 2 and Bax) after ischemia and reperfusion (IR) during cardiopulmonary bypass (CPB). Methods: Ninety felines were randomized into 3 groups: control group( n =30), in which CPB was conducted without aortic cross clamping (ACC); IR group( n =30), with 60 min ACC followed by reperfusion, and cardioplegia was used during ACC; IPC group( n =30), with protocol similar to that of IR group except for three cycle 15 min IPC before ACC. The myocardial apoptosis changes were analyzed by DNA electrophoresis and TdT mediated dUTP nick end labelling (TUNEL).The expression of Bcl 2 and Bax were analyzed by using immunohistochemistry with SABC method. The ratio of apoptosis and Bcl 2 and Bax positive cells were quantified with flow cytometry. Results: No significant changes were observed in control group. Myocardial cell apoptosis were only detected during the later period of reperfusion in IR group and IPC group. IPC markedly attenuated the ratio of apoptosis caused by reperfusion from (6.932±0.638) % in IR group to (3.021±0.254) % in IPC group at the end of reperfusion ( P <0.05). Bcl 2 expression was upregulated and Bax expression was downregulated in IPC group compared to that in IR group ( P <0.05). Conclusion: IPC can lower the ratio of apoptosis and protect myocardial cells from IR injury by increasing Bcl 2 expression and decreasing Bax expression during CPB.

关 键 词：缺血预适应 再灌注性心肌细胞凋亡 BCL-2 BAX 蛋白 表达 体外循环 

分 类 号：R654.1[医药卫生—外科学]