心肌反复短暂缺血对家兔急性心肌梗塞再灌注的影响

THE EFFECTS OF REPETITIVE BRIEF EPISODES OF ISCHEMIA ON ACUTE MYOCARDIAL INFARCTION-REPERFUSlON IN RABBITS

心肌预先反复短暂缺血及维拉帕米(异搏定)均可抑制急性心肌梗塞(AMI)再灌注后血小板聚集功能的增强及血浆TXB:水平的增高反应,并缩小其梗塞范围。但在心肌预先反复缺血的基础上,维拉帕米却无上述效应。

The effects of repetitive brief episodes of ischemia and verapamil on acute myocardial infarc-tion-reperfusion (AMI-R) were studied. Rabbits were divided into 4 groups. Group A and B received 60 min. coronary occlusion. Group C and D were preconditioned with three 5 min. coronary occlusions separated by 15 min. of reperfusion, followed by a sustained 60 min. occlusion. All rabbits were allowed 180 min. of reperfusion thereafter. Group A and C were controls. Group B and D received verapamil (1 mg/kg) before ischemia. The results showed that platelet aggregation (PAg), circulating platelet aggregates (CPA)and plasma TXB: level increased significantly after AMI-R(groupA). Verapamil (group B) and preconditioning with repetitive ischemia (group C) could inhibit the increasing reaction and limit infarct slze(IS)respectively. But verapamil could neither further limit IS nor inhibit the increase of PAg, CPA and plasma TXB_2 level after AMI-R preconditioned with repetitive ischemia.