异丙酚对急性心肌梗死大鼠心脏功能的影响

The effects of propofol on myocardial function in rats with acute myocardial infarction

目的 观察异丙酚对急性心肌梗死大鼠血液动力学影响的量-效关系以及心肌梗死范围和心肌超微结构的变化。方法 将急性心肌梗死模型的大鼠随机分为5组（n=8）,对照组（Ⅰ）,其余大鼠分别持续静脉输注30（Ⅱ）、45（Ⅲ）、60（Ⅳ）、75（Ⅴ）mg·kg-1·h-1异丙酚30min。测定输注异丙酚30min血药浓度,观察血液动力学、心肌梗死范围和心肌超微结构的变化。结果 血药浓度为（3.4±0.9）～（12.9±2.4）μg/ml时,平均动脉压（MAP）、心率（HR）、左室收缩压（LVSP）、左室内压力变化最大速率（±dp/dtmax）、心肌耗氧指数（MOCI）均呈剂量依赖性下降（P<0.05）,左心室舒张末压（LVEDP）无明显变化（P>0.05）,心肌梗死面积为23.7％～29.2％（P>0.05）,心肌超微结构无显著性差异。结论 在血药浓度（3.4±0.9）～（12.9±2.4）μg/ml范围内,异丙酚对血液动力学及心收缩功能呈剂量依赖性抑制,对心肌梗死范围和心肌细胞超微结构无明显影响。

ve To investigate the effects of propofol on hemodynamics, size of myocardial infarct area, ultrastructure of myocardial tissue and the plasma propofol concentration-response relationship in rats with acute myocardial infarction.Methods Forty male Wistar rats weighing (296.9 ± 16.8)g were anesthesized with intraperitoneal urethane. The animals were then tracheomized and mechanically ventilated. Needle electrodes of ECG were appropriately inserted. If the ECG was normal, left femoral artery was cannulated for determination of MAP and femoral vein was cannulated for drug administration. Cardiac catheter was placed via common carotid artery. Acute myocardial infartion was produced by ligation of the anterior descending branch of left coronary artery (LAD) and myocardial infartion was confirmed by ST elevation>0.1mv. The forty animals were randomly divided into five groups of eight animals each: in group I normal saline 5.2ml·kg-1·h-1 was infused (control); while in group II , III , IV and V propofol was infused at a rate of 30,45, 60,75mg·kg-1·h-1 for 30 min. MAP, HR, left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), ± dp/dtmax and myocardial oxygen consumption index were recorded before and 30 min after drug administration. Blood samples was taken at the end of 30 min propofol infusion for determination of plasma propofol concentration. Myocardial tissue was taken for electron microscopic examination in some rats. The extent of infarct area was determined by TTC staining. Results The plasma propofol concentration ranged from 3.4±0.9 to (12.9 ± 2.4) μg/ml. Propofol significantly decreased MAP, HR, LVSP,± dp/dtmax and myocardial oxygen consumption index in a dose-dependent manner. The size of myocardial infarct area ranged from 23.7% to 29.2% but there was significant difference in the size of infarct area and myocardial ultrastructure between the five groups. Conclusions Propofol inhibits hemodynamics in rats with acute myocardial infarction but has little effect on infarct size and ultrastruture of myocardial tissue.