阿米洛利同系物和心肌缺血预处理对再灌注心肌的影响

目的：阿米洛利同系物（ethylisopropyl-amiloride,EIPA)和心肌缺血预处理（ischemic preconditioning, IPC)对心肌细胞保护效果的关系。方法：取心电图正常的28只大鼠随机分为3组：缺血／再灌注组（ischemia-reperfusion,I/R)，EIPA（缺血前给EIPA）和IPC组（缺血5min,再灌注5min，重复3次）。然后3组均持续阻断冠状动脉30min,再灌注120min，观察心肌梗死面积（infarct size,IS)，血清肌酸激酶同工酶（CK－MB）和室性心律失常发生率。结果：IS在EIPA组IPC组与I／R组比减少，分别减少51．82％和54．19％，EIPA组和IPC组CKMB显著低于I／R组（P＜0．01）。而EIPA组和IPC组之间无差异。在缺血前给予EIPA和缺血预处理，可使缺血及再灌注期间室性心律失常明显减少（P＜0．01）。结论：缺血前给予EIPA对在体心脏缺血再灌注损伤具有保护作用，与缺血预处理具有类似效果。

Inuence of Ethylisopropyl Amiloride and Ischemic Preconditioning on Reperfused Myocardium

Objective: Our purpose was to compare the protective effects of ethylisopropyl-amiloride(EIPA), and ischemic preconditioning (IPC) on myocardial cell. Methods: Twenty-eight rats with normal electrocardiograph were randomly divided into 3 groups: ischemia-reperfusion group (I/R group ),EIPA group, ischemic preconditioning group(IPC group). Five-minute ischemia followed by 5-minute reperfusion were repeated for 3 times.The EIPA was given before block coronary artery in EIPA group. Then , all coronary arteries were blocked for 30 minutes, followed by 120 minutes of reperfusion. Myocardial infarction size (IS), serum MB isoenzyme of creatine kinase (CK-MB), the incidence of ventricular arrhythmia were used as the indicators of myocardial injury. Results: The myocardial infarction areas after ischemic reperfusion in EIPA group and IPC group were much smaller than that of the I/R group.The EIPA and IPC were helpful in reducing the myocardial infarction area . The IS of EIPA group decreased by 51.82%, while by 54.19% in the IPC group. The levels of CK-MB in EIPA group and IPC group were significantly lower than that in I/R group( P <0.01). Administration of EIPA and ischemic preconditioning before ischemia could decrease the release of CK-MB by 50% . No significant difference existed between EIPA group and IPC group. Administration of EIPA and ischemic preconditioning before ischemia could reduce ventricular arrhythmia during ischemia and reperfusion. Conclusion: Administration of EIPA before ischemia and ischemic preconditioning have protective effect on myocardial ischemic-reperfusion injury .