ETA受体拮抗剂BQ123对急性心肌梗死后梗死面积与左室重构的影响

目的　探讨在急性心肌梗死 (AMI)后使用内皮素受体A拮抗剂 (ETA 受体拮抗剂 )对梗死面积与心室重构的影响。方法　将 2 2只兔随机分为 4组 ,1周实验组 (n =6 )和 1周对照组 (n =5 ) ,4周实验组 (n=6 )和 4周对照组 (n =5 ) ,结扎左冠状动脉前降支建立心肌梗死模型。实验组每天静脉滴注ETA 受体拮抗剂BQ12 3,对照组每天使用等量生理盐水作相同处理 ,分别于 1周和 4周后取出心脏 ,测量梗死面积并计算左室质量指数。所有动物均在结扎冠状动脉前和取出心脏前行超声心动图检测心脏结构指标。结果　各实验组心肌梗死面积均较其对照组明显缩小 (P <0 . 0 5 )、 4周实验组室间隔厚度 (IVd)、左室后壁厚度 (LVPWd)及左室舒张末容 (LVEDV)增加程度均比 4周对照组显著减轻 (P <0 . 0 5 ) ,左室质量指数 (LVMI)明显于 4周对照组(P <0 .0 5 )。结论　AMI后使用ETA 受体拮抗剂能缩小梗死面积、减轻心室重构而发挥着对心脏的保护作用。

Effect of endothelin-A receptor antagonist BQ123 on infarcted size and on ventricular remodeling post-AMI

Objective To elucidate cardioprotective effects of ET A receptor antagonists after acute myocardial infarction(AMI), especially effects of long-term treatment with ET A receptor antagonists on infarcted size and ventricular remodeling post-AMI.Methods 22 rabbits were randomly divided into 4 groups: 1 week experiment group(n=6) and control group(n=5), 4 weeks experiment group(n=6) and control group(n=5). The models of myocardial infarction were induced in all animals by ligating the beginning of left ventricular anterior descending coronary arteries. All the animals in experiment groups were treated with intravenous infusion of ET A receptor antagonist BQ123, and control groups were treated by the same way with qual dose of the solutions of 0.9% NaCL.The animals were killed after 1 and 4 weeks respectively, and the hearts were removed, and infarcted sizes were calculated as percentage of the left ventricle, and left ventricle mass index(LVMI) was calculated. The indices of left ventricular structure and cardiac function were assessed by two dimensional echocardiography and Doppler echocardiography before ligating coronary and being killed. Results Infarcted sizes in experiment groups compared to their control groups respectively were significantly reduced. LVMI, the increased degree of interventricular depth(IVd), left ventricular posterior wall depth(LVPWd),and expansion of left ventricular end-diastolic volume(LVEDV) in 4 weeks experiment group were significantly lower than 4 weeks control group.Cardiac function improved significantly in 4 weeks experiment group compared to its control group(P<0.05). Conclusions Treatment with ET A receptor antagonist BQ123 during AMI could decrease infarcted sizes and ventricular remodeling significantly.