缺血后适应的不同干预时间对家兔短期缺血再灌注心肌细胞凋亡影响

Effect of intervention time on apoptosis of myocardial cells in short-term ischemia and reperfusion in rabbits

目的:探讨缺血后适应的不同干预时间对兔局部短期缺血再灌注心肌细胞凋亡及Bcl-2、Bax蛋白表达的影响。方法:实验于2008-06/2010-06在石河子大学医学院中心实验室完成。36只新西兰大白兔随机分成6组(n=6);假手术对照组(S组)、缺血/再灌注对照组(IR组)、缺血后适应组(Post1-4组)。除S组外,其余5组均接受左冠脉前降支15min阻断和30min再灌注,Post1-4组在15min缺血后分别接受连续3次缺血/再灌注10s、15s、30s及45s的后适应。TUNEL分析检测兔短期缺血再灌注心肌组织的细胞凋亡情况,免疫组织化学方法检测Bcl-2、Bax蛋白的表达。结果:缺血后适应各组心肌细胞凋亡指数显著低于缺血再灌注组(P<0.01)。Bcl-2基因的蛋白表达量Post1-4组高于IR组[(6.83±1.17),(7.33±1.37),(8.50±1.05),(6.83±1.47),(3.67±1.37),P<0.05];Bax基因的蛋白表达量Post1-4组低于IR组([7.33±1.21)(,6.50±1.05)(,4.33±0.82)(,6.50±1.05),(8.83±1.17),P<0.05]。缺血后适应Post3组与Post1、Post2、Post4组两两比较差异有统计学意义(P<0.05),而Post1、Post2、Post4组两两比较差异无统计学意义。结论:短暂缺血/复灌的持续时间10s、15s、30s及45s均可减少家兔缺血再灌注心肌损伤,而30s是最佳的短暂缺血/复灌的干预时间。

Objective：To discuss the effects of myocardial cell apoptosis and expressions of Bcl-2 and Bax protein of different in-terfere time of ischemic postconditioning（Post） during ischemia/reperfusion period on myocardial cell in rabbits.Methods：The experi-ment was finished in the Central Laboratory of Medical College,Shihezi University,from June 2008 to June 2010.36 New Zealand rab-bits were randomly divided into 6 groups（n = 6）;sham operation group（Group S）,ischemia /reperfusion group（Group IR）,ischemic postconditioning group（Group Post1-4）.In addition to group S,the other five groups were accepted 30 minutes of reperfusion following 15 minutes of left anterior descending coronary artery occlusion.Group post1-4 were treated respectively with ischemia postconditioning after 3 continuous cycles of ischemia /reperfusion by 10s,15s,30s and 45s.Cardiomyocyte apoptosis were determined by in situ TDT-mediated dUTP nick end labeling（TUNEL）.The expression of Bcl-2 and Bax proteins in apoptotic myocardiac cells were detected by immunohistochemistry.Results：Compared with Group IR,Apoptotic Index was significantly lower in Group Post1-4（P〈0.01）.Bcl-2 expression in Group Post1-4 was higher than in Group IR,while Bax expression in Group Post1-4 was lower than in Group IR.Postcon-ditioning Post3 group and Post1,Post2,and Post4 group was statistically significant compared each other（P 〈0.05）,while Post1,Post2,Post4 group was no statistical difference.Conclusion：The duration of transient ischemia /reperfusion of 10s,15s,30s and 45s may reduce myocardial ischemia/reperfusion injury,and 30s is the best intervention time of short-lived ischemia /reperfusion in rabbits.