缺血预处理对兔缺血再灌注心肌bcl-2,bax,p53基因表达的影响

Effect of ischemic preconditioning on myocardial bcl-2,bax,p53 gene expression during ischemia/ reperfusion period in rabbits

目的 :探讨缺血预处理对兔在体心脏局部缺血再灌注过程中心肌细胞bcl 2 ,bax ,p5 3基因表达的影响。方法 :2 4只新西兰白兔随机分成 3组 (n =8) :假手术对照组 (P组 )、缺血再灌注对照组 (IR组 )、缺血预处理组(IP组 )。除P组外 ,其余两组均接受左冠脉前降支 3h阻断和 3h再灌注。IP组在 3h缺血前接受连续 3次每次缺血 5min ,再灌注 5min的预处理。取心肌缺血区边缘组织用流式细胞仪测凋亡指数 (AI)和bcl 2 ,bax ,p5 3基因的蛋白表达量。结果 :凋亡指数 ,IP组 ( 5 .85± 1.5 9) %较IR组 ( 13.83± 3.98) %显著减少 (P <0 .0 1)。bcl 2基因的蛋白表达量IP组高于IR组 ;bax ,p5 3基因的蛋白表达量IP组低于IR组。结论 :缺血预处理抑制缺血再灌注所致心肌细胞凋亡与上调bcl 2基因的蛋白表达 ,下调p5 3和bax基因的蛋白表达有关。

Objective To investigate the effects of ischemic preconditioning on myocardial bcl-2,bax,p53 gene expression during ischemia/ reperfusion period in rabbits. Methods Twenty four rabbits were randomly allocated to three groups (n=8),pseudo-operation group(Group P),ischemia/ reperfusion group (Group IR) and ischemic preconditioning group(Group IP). Group IR and Group IP were subjected to three hours of left anterior descending coronary artery occlusion followed for three hours of reperfusion. Ischemic preconditioning was achieved by three 5-minute cycles of ischemia, each followed by 5 minutes of reperfusion. Apoptosis index(AI ) and protein expression of Bcl-2,Bax,and p53 in the border zone of myocardium of ischemic area at risk were obtained with a flow cytometry. Results Compared with Group IR,AI was significantly reduced in Group IP(P<0.01). Bcl-2 expressions was higher in Group IP than in Group IR, while bax and p53 expressions were lower in Group IP than in Group IR. Conclusion The rabbit myocardial apoptosis induced by ischemic preconditioning inhibited ischemia-reperfusion in vivo partly related to the modulating of bcl-2, bax and p53 expression.