大鼠急性心肌梗死心肌ER表达的变化规律

An experimental study on changes of estrogen receptor in myocardium after acute myocardial infarction in rats

目的探讨大鼠急性心肌梗死后非梗死区心肌雌激素受体(ER)的变化规律。方法选择雄性大鼠120只,分为正常组、手术组和假手术组,建立急性心肌梗死模型,在不同的时间点处死大鼠取心肌组织,常规HE染色,用免疫组化SP法和显微图像分析对ER表达的变化进行定量研究,用统计学方法进行处理,观察是否有统计学意义。结果急性心肌梗死后非梗死区ER的表达随着时间逐渐增多,手术后12h内增高不明显,24h开始增多明显,4～9d增多更为明显。结论急性心肌梗死后,非梗死区的心肌细胞可能通过增加ER的表达,发挥对心脏急性心肌缺血的保护作用。

Objective To investigate temporal expression of estrogen receptor (ER) in myocardium at non-infarct zone after acute myocardial infarction (AMI) in rats. Methods 120 healthy, male SD rats were randomly divided into three groups: control group, left anterior descending coronary artery (LAD) occlusion group and sham operation group with 8 rats in each group. The murine AMI-model was established by LAD ligation after anesthetization, and the rats in both LAD occlusion group and sham operation group were sacrificed at 2h, 4h, 8h, 12h, 1d, 2d, 4d, and 9d after occlusion. Myocardial samples were collected. H.E and ER immunohistochemical staining were performed. The results were quantitatively evaluated by image analysis system. The data were statistically analyzed with SPSS for Windows. Results ER expression in non-ischemic cardiomyocytes after LAD occlusion became more prominent with extension of LAD occlusion period. There was no significant difference within 12h after AMI, while ER expression was enhanced significantly 24h after ischemia. The enhancement were more evident from 4 to 9 days. Conclusion The results suggested that protective role may be initiated in response to acute ischemia in cardiac cells at non-infarct zone by increased ER expression after LAD occlusion in rats.