【摘要】 本文观察了兼有α₁受体阻断作用的β受体阻断剂柳胺苄心定（labetalol,简称Lab）对急性心肌梗塞家兔心肌血流量（放射性微球法）,梗死范围及左室功能的影响,并与心得安比较。结果表明:小剂量Lab（1mg/kg）主要显示β受体阻断效应,它能减慢心率,降低心肌耗氧量,降低非梗死区心肌血流量,缩小梗死范围,其效应与心得安相似,且能改善左室舒缩功能;大剂量Lab（5mg/kg）,能同时阻断α₁和β受体,它能降低动脉血压,相对增加各区心肌血流量,显著减少心肌耗氧量,缩小梗死范围。结果提示:在急性心肌梗塞治疗中,同时阻断α₁和β受体较单纯阻断β受体优越。更多还原

【Abstract】 The effects of labetalol （Lab）, an alpha₁ and beta adrenoceptor blocking agent, and propranolol on myocardial blood flow （MBF）, infarct size （IS） and left ventricular function during coronary occlusion in the rabbits were studied. After left ventricle coronary artery was ligated, the 53 rabbits were divided into 4 groups: control, propranolol 0.5mg/kg, Lab 1mg/kg and Lab 5mg/kg. After 30 min coronary occlusion, regional blood flow was determined by radioactive biological microspheres technique. After 5 hours occlusion, left ventricular pressure and its differentiation were measured and IS was estimated with NBT staining method. The results show: Lab 1mg/kg demonstrated mainly beta adrenoceptor blockade. It slowed heart rate, diminished myocardial oxygen consumption, decreased MBF except for infarct zone and reduced IS, the effects were similar to propranolol. Furthermore, it improved left ventricular function while propranolol did not. Lab 5mg/kg blocked alpha₁ and beta receptor simultanously. It decreased arterial blood pressure and heart rate, increased blood flow of myocardium and kidney relatively, diminished myocardial oxygen requrement more markedly than propranolol and reduced IS. These imply that simultanous alpha₁ and beta blockade have some advantage over beta blockade alone in the treatment of acute myocardial infarction.更多还原