雌激素促大鼠急性心肌梗死后心肌血管生成及受体介导机制*

Objective To study the influence of estradiol on myocardial angiogenesis and the expression of estrogen receptors in a rat model of myocardial infarction .Methods Acute myocardial infaction(AMI) model was bulit by ligation of Left anterior descending coronary in ovariectomized Sprague-Dauley rats..They were treated with different doses of estradiol Benzoate..Estradiol concentration in serum was measured by Radioimmunoassay before AMI and 4 weeks later,microvascular density in myocardium was evaluated through detection of expression of Ⅷ factor by Immunohistochemistry and estrogen receptorαandβprotein in the myocardium were deteced with western blot at 28 days after AMI. Result Estradiol levels in serum significant degraded after ovariectomized and heightened in the groups with different doses of estradiol. microvascular density in myocardium 4 weeks after AMI in ovariectomized group were obviously lower than acute myocardial infarction group and ovariectomized estrogen therapy groups, estrogen replacement therapy group was the highest. The expression of estrogen receptorαandβprotein in the myocardium showed significant different. estrogen replacement therapy group was the highest and ovariectomized group was the lowest .Conclusion Estrogen improves myocardial angiogenesis in rats after AMI,this efffect could related to the expression of estrogen receptorαandβin myocardium and ER-αplays a major role in this process.