ET_A受体拮抗剂BQ123对心肌梗死局部心肌组织中ET-1和ET受体分布的影响

Effect of endothelin-A receptor antagonist BQ123 on the distribution of ET-1 and ET receptor in local myocardium after AMI

目的 探讨在急性心肌梗死(AMI)时，使用内皮素受体A拮抗剂(ET_A受体拮抗剂)后对局部心肌组织ET-1和ET受体分布的影响。方法 将22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AMI模型。实验组每天静脉滴注ET_A受体拮抗剂BQ123，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。采用免疫组化染色和图像分析法检测1周和4周各组动物左心室非梗死区、梗死边缘区和梗死中心区心肌组织的中ET-1和ET受体的分布。结果 免疫组化染色和图像分析结果显示：各实验组ET-1和ET受体的分布均明显少于各自对照组相应部位(P＜0．05)。结论 AMI后，使用ET_A受体拮抗剂能减轻局部心肌组织ET-1和ET受体的上调程度。

Objective To elucidate whether the distribution of ET-1 and ET receptor （ETR） in local myocardium is different after application of ETA receptor antagonists during acute myocardial infarction （AMI）. Methods Twenty-two rabbits were randomly divided into 4 groups： 1 week experimental group （ n = 6） and control group（ n = 5） ; 4 weeks exprimental 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 exprimental groups were treated with intravenous infusion of ETA receptor antagonist BQ123, and those in control groups were treated by the same way with equal volume of 0.9% NaCl solution. The animals were sacrificed after 1 and 4 weeks respectively, and the hearts were removed. ET-1-like-immunoreactivity （ET-1-ir） and ETR-like-immunoreactivity（ETR-ir） in left ventricular non-infarcted region （LVN）, left ventricular myocardial infarcted border region （LVMIB） and left ventricular myocardial infarcted central region （LVMIC） were examined by immunohistochemistry and image analysis method. Results The upregulated levels of ET-1 and ETR expression in each experimental group were significantly lower than its control group respectively. Conclusious Treatment with ETA receptor antagonist BQ123 during AMI could reduce the upregulation of ET-1 and ETR expression.