急性心肌缺血大鼠体内AngⅡ与血流动力学参数的变化

The changes of angiotensin Ⅱ and hemodynamics in rats with acute myocardial ischemia

目的观察急性心肌缺血大鼠的血流动力学参数的变化过程及其与肾素-血管紧张素系统的关系。方法健康雄性SD大鼠16只随机分为缺血组和对照组,用垂体后叶素注射建立心肌缺血模型,连续观察大鼠血流动力学变化,并于0、20、40、60min分别记录左室收缩末压(LVESP)、左室舒张末压(LVEDP)、心室内压最大上升和下降速率(±dp/dtmax),于1h末处死大鼠,检测血清和心肌匀浆的AngⅠ和AngⅡ含量。结果缺血组的LVESP和±dp/dtmax有显著降低,而LVEDP显著升高,和对照组相比均差异有统计学意义(P<0.05)。缺血组的血清和心肌组织匀浆中的RA活性较对照组显著增高(P<0.05),AngⅡ的含量亦显著高于对照组(P<0.05)。缺血组心肌组织内AngⅡ含量与60min时的+dp/dtmax呈显著负相关(P=0.000)。结论大鼠急性心肌缺血时,会发生血流动力学改变和左心室功能的减退,这些改变与血清和缺血心肌局部肾素-血管紧张素系统有着密切的关系。

Objective To investigate the changes of hemodynamical parameter in rats with myocardial ischemea and the relationship between the changes and the renin angiotensin system.Methods 16 SD rats were randomly divided into two groups：the ischemia group and the control group.Models of myocardial ischemia were established through giving injections of pituitrin to the myocardial ischemea rats,and then observations on the changes of hemodynamicia were conducted and LVESP,LVEDP and ±dp/dt max were recorded at intervals of 0 min,20 min,40 min,60 min,respectively.At last the rats were put to death one hour after the injection to test their blood serum and the contents of AngⅠ and AngⅡ in the myocardium homogenate.Results There was apparent decrease of LVESP and ±dp/dt max and increase of LVEDP in the ischemia group compared to the control group with a statistical discrepancy（P〈0.05）.The ischemea rats＇ blood serum and the RA activity in their myocardial homogenate are higher than the controls（P〈0.05）,so are the contents of AngⅡ （P〈0.05）.The AngⅡ content in the myocardial homogenate in the ischemea rats exhibits negative correlation with the ＋dp/dt max recorded at 60 min.Conclusions Changes of hemodynamia and decrease of Left Ventricular Function occur in rats with acute Myocardial ischemia.The changes have close correlation with blood serum and Renin-Angiotensin System of the ischemia cardiac muscle parts.