Ali S M, Brown E J, Nallapati S R, Alhaddad I A
Department of Medicine, Bronx-Lebanon Hospital Center, New York 10457, USA.
Coron Artery Dis. 1998;9(12):815-21. doi: 10.1097/00019501-199809120-00006.
To examine the effects of early angiotensin-converting enzyme (ACE) inhibitor therapy after myocardial infarction on infarct expansion in an experimental rat model.
ACE inhibitor therapy within 24 h of acute myocardial infarction (AMI) reduces mortality by unknown mechanism(s).
Rats underwent permanent coronary artery occlusion. A treated group received enalapril (1.9+/-0.2 mg/kg) daily in drinking water beginning 2 h after coronary artery occlusion, a time too late to reduce infarct size. Rats were sacrificed 2 days or 2 weeks after myocardial infarction. Hearts were arrested and fixed at a constant pressure, then sectioned and photographed for morphometric analysis.
Infarcts in the control group expanded between 2 days and 2 weeks after myocardial infarction (expansion index 0.7+/-0.1 versus 2.5+/-0.4, P< 0.05). However, infarct expansion remained unchanged in the enalapril group between 2 days and 2 weeks after myocardial infarction (expansion index 0.8+/-0.1 versus 1.3+/-0.1, NS). Two weeks after myocardial infarction, the enalapril group had fewer expanded infarcts than the control group (expansion index 1.3+/-0.1 versus 2.5+/-0.4, P< 0.05). While left ventricular volume increased in the control group between 2 days and 2 weeks after myocardial infarction (0.17+/-0.01 ml versus 0.36+/-0.03 ml, P< 0.05), it remained constant in the enalapril group (0.22+/-0.02 ml versus 0.25+/-0.03 ml, NS). Two weeks after myocardial infarction, the left ventricles were larger in the control group than in the enalapril group (0.36+/-0.03 ml versus 0.25+/-0.03 ml, P< 0.05).
Treatment with enalapril initiated 2 h after AMI prevented left ventricular dilation by limiting infarct expansion. This may explain the mechanism by which ACE inhibitor therapy started within 24 h of an AMI improves survival 5-6 weeks after infarction.
在实验性大鼠模型中研究心肌梗死后早期应用血管紧张素转换酶（ACE）抑制剂治疗对梗死扩展的影响。
急性心肌梗死（AMI）24小时内应用ACE抑制剂治疗可降低死亡率，但其机制尚不清楚。
对大鼠进行永久性冠状动脉闭塞。治疗组在冠状动脉闭塞2小时后开始每日通过饮水给予依那普利（1.9±0.2mg/kg），这个时间点过晚，无法减小梗死面积。在心肌梗死后2天或2周处死大鼠。使心脏停搏并在恒定压力下固定，然后切片并拍照以进行形态计量分析。
对照组梗死灶在心肌梗死后2天至2周之间扩大（扩展指数0.7±0.1对2.5±0.4，P<0.05）。然而，依那普利组梗死灶在心肌梗死后2天至2周之间无变化（扩展指数0.8±0.1对1.3±0.1，无显著性差异）。心肌梗死后2周，依那普利组梗死灶扩大的数量少于对照组（扩展指数1.3±0.1对2.5±
