【作者】 单亮；

【导师】 郑方胜； 廉哲勋；

【作者基本信息】 青岛大学 ， 心血管内科， 2005， 硕士

【摘要】 目的 通过在体兔心肌缺血再灌注模型比较缺血预适应、缺血后处理和ATP药物后处理对急性心肌缺血再灌注损伤保护作用及探讨缺血后处理的机制。方法32只兔随机分为4组①对照组(con):结扎冠脉40分钟,再灌注180分钟。②缺血预适应组(pre-con):三次短暂结扎冠状动脉(5分钟闭塞,10分钟再灌注,循环3次),其余同对照组。③缺血后处理组(post-con):结扎冠脉40分钟,再通30秒,结扎30秒,重复3次,再灌注180分钟。④ATP后处理组(ATP):结扎冠脉40分钟,再通后即刻给予ATP300ug/kg/min,耳缘静脉注射持续30分钟,再灌注180分钟。4组均在缺血及再灌注同时行心电图和心肌酶检查,再灌注末抽血离心测定SOD、MDA。实验结束,速取心脏处理测定梗死面积。实验过程采集心电信息。结果和对照组相比,Pre-con、Post-con和ATP组再灌注各个时间点肌酸磷酸激酶(CPK)均降低(P<0.05);Pre-con、Post-con和ATP组坏死面积占总面积之比均小于对照组,分别比对照组减少43%、41%和26%(P<0.01);Post-con组血清中SOD的含量高于对照组(P<0.05),MDA的含量低于对照组(P<0.05)。缺血预适应组、后处理组和ATP组冠脉结扎后ECG中ST段异常抬高幅度的总mV数(∑ST)明显低于对照组(P<0.05),ST段异常抬高的导程数(NST)亦低于对照组。结论 缺血后处理和缺血预适应具有相似的缺血心肌保护作用,可以减少心肌酶的释放,减少梗死面积,减小损伤电流;减少再灌注心律失常的发生。后处理应在再灌注的即刻实施,才能取得心脏保护效果;缺血后处理的机制部分可能是通过减少自由基释放、减轻脂质过氧化损伤并增加SOD的产生实现的。ATP再灌注时应用可以减少梗死面积,使用方便,可以成为减少再灌注损伤的常规药物。更多还原

【Abstract】 Objective To evaluate the cardioprotective effects offered by the postconditioning and pharmacological-conditioning induced by ATP comparing with the preconditioning and discuss postconditioning’ mechanism. Method In anesthetized open-chest rabbits, the left anterior descending artery (LAD)was occluded for 40 mins and reperfused for 3 hours. In controls(n=8), there was no intervention. In Pre-con(n=8), the LAD was occluded for 5 min and reperfused for 10 min before the prolonged occlusion. In Post-con(n=8),at the start of reperfusion, three cycles of 30-s reperfusion and 30-s LAD reocclusion preceded the 3 hours of reperfusion. In ATP group(n=8), at the start of reperfusion, ATP is injected as a velocity of 300ug/kg/min continued 30rains. Results Infarct size was significantly less in the Pre-con(P<0.001)、 Post-con(P<0.01) groups and ATP(P<0.05) compared with controls. The levels of CPK in the Pre-con 、 Post-con and ATP groups were significantly less than controls on the three points. SOD, a antioxidant ,was significantly higher at 3 hour of reperfusion in Post -con versus controls(P<0.05) associated with a decrease in MDA levels versus controls(P<0.05). Conclusion These data suggest that Post-con is as effective as Pre-con in reducing infarct size and CPK of serum. Post-con is partly due to reducing the injury of oxygen free radical. When used as reperfusion, ATP is effective and ATP may become a promising agent.更多还原