超速起搏预适应的延迟保护与热休克蛋白27的表达

Delayed cardioprotection effect induced by overdrive pacing preconditioning and expression of heat shock protein 27

目的:观察超速心室起搏(VOP)预适应延迟保护阶段热休克蛋白27(HSP27)的表达水平。方法:新西兰兔24只,随机分为3组,缺血再灌注(I/R)空白对照组,起搏组,起搏+放线菌素D组。制作I/R和超速起搏预适应的动物模型,检测肌酸激酶(CK)和肌酸激酶-同工酶(CK-MB)水平的变化,动态描记再灌注时心电图,以免疫组织化染色法检测HSP27抗原表达水平。结果:I/R后起搏组心肌酶的水平均明显低于I/R空白对照组和起搏+放线菌素D组(P<0.01);I/R空白对照组在再灌注过程中共有5只(62.5%)发生心律失常,起搏+放线菌素D组有4只(50.0%),而起搏组无心律失常发生。起搏组心律失常发生率明显低于I/R空白对照组和起搏+放线菌素D组(P<0.05)。起搏组HSP27阳性表达++者(37.5%)明显高于I/R空白对照组和起搏+放线菌素D组(0,12.5%,P<0.05)。结论:心室超速起搏预适应有心脏保护作用,其机制可能与热休克蛋白27表达增加密切相关。

Objective：To observe delayed cardioprotection effect induced by preconditioning from ventricular overdrive pacing（VOP） and expression level of heat shock protein 27（HSP27） in phase of ischemia-reperfusion（I/R）.Methods：A total of 24 New Zealand rabbits were randomly divided into I/R blank control group,pacing group and pacing ＋ actinomycin D group.Animal models of I/R and VOP preconditioning were established.Changes of levels of creatine kinase（CK） and creatine kinase isoenzyme（CK-MB） were measured,electrocardiogram was recorded during I/R.Immunohistochemical staining was used to detect HSP27.Results：During I/R,levels of CK and CK-MB in I/R pacing group were significantly lower than those of I/R blank control group and pacing ＋ actinomycin D group（P〈0.01 all）;during I/R,there were 5（62.5%） and 4（50.0%） rabbits occurring arrhythmias in I/R blank control group and pacing ＋ actinomycin D group respectively,and no arrhythmia occurred in pacing group.Incidence rate of arrhythmia in pacing group was significantly lower than those of other two groups（P〈0.05）.Cases with HSP27 positive expression＋＋in I/R pacing group（37.5%）was significantly higher than those of I/R blank control group and pacing ＋ actinomycin D（0,12.5%,P〈0.05 all）.Conclusion：Preconditioning from overdrive ventricular pacing possesses cardioprotection effect,and its mechanism may be close correlation with increased expression of heat shock protein 27.