缺血后处理对急性心肌缺血再灌注兔心脏的保护作用

目的　研究缺血预处理和缺血后处理对兔心收缩功能和心肌梗死范围的影响 ,探讨在体条件下 ,缺血后处理是否具有减轻缺血心肌再灌注损伤的作用 .方法　采用兔缺血再灌注模型 ,分别以缺血前短暂心肌缺血作预处理 ,或缺血后再灌前 ,多次短暂再灌停灌作缺血后处理 .以多导生理仪监测和记录血流动力学指标 ,TTC法确定心肌梗死范围 .结果　缺血预处理组及缺血后处理组心肌梗死范围分别为 (14.7±6 .0 ) %和 (12 .5± 5 .4) % ,均低于对照组 (2 6 .7± 6 .7) % (P<0 .0 1) ,兔左室内压峰值 (L VSP)恢复率和 dp/dtmax恢复率均高于对照组 ,再灌注心律失常发生率明显低于对照组 (P<0 .0 5 ) .结论　缺血后处理与缺血预处理对缺血心脏具有相似的保护作用 ,可改善缺血 -再灌心脏收缩功能 ,缩小心肌梗死范围

Protective effect of ischemic postconditioning on rabbit hearts with acute myocardial ischemia and reperfusion

AIM To explore the possible beneficial effect of ischemic postconditioning in acute ischemic heart, and to compare the effect with that of ischemic preconditioning. METHODS With a rabbit model of acute myocardial ischemia reperfusion, ischemic postconditioning was achieved by several brief reperfusion ischemia before persistent reperfusion, while in ischemic preconditioning group animals were given several brief ischemia reperfusion before ischemia. Myocardial infarct size was determined by dual staining with triphenyltetrazolium chloride and Evan's blue dye. RESULTS Compared with those of control, myocardial infarct size and the rate of arrhythmia occurrence during reperfusion in both of the conditioned groups were significantly reduced ( P <0 01 and P <0.05, respectively); Left ventricular systolic pressure (LVSP) and dp/dt max of the heart were also better reserved and recovered during reperfusion in the conditioned groups. CONCLUSION The results demonstrate for the first time that ischemic postconditioning, like ischemic preconditioning, exerts cardioprotective effect and could attenuate reperfusion injury in ischemic heart.