Effects of estrogen on peripheral blood stem cells and angiogenesis in myocardial infarction rats / 中国药理学通报

ABSTRACT

Aim To study the influence of estradiol on peripheral blood stem cells and angiogenesis in a rat model of myocardial infarction.Methods Acute myocardial infarction(AMI)model was bulit by ligation of left anterior descending coronary in ovariectomized SD rats.Then,they were treated with different doses of estradiol benzoate.CD34+ cells in myocardium at 24 h after AMI were detected by immunohistochemistry,and CD34+ cells in peripheral blood were measured by flow cytometry on day 1,3 and 7 after AMI.The expression of stromal cell-derived factor-1(SDF-1)in myocardium on day 1,3 and 7 after AMI and capillary density in myocardium at 28 days after AMI were evaluated by immunohistochemistry.Results CD34+ cells in peripheral blood and myocardium,the expression of SDF-1 and capillary density at 4 weeks after AMI in ovariectomized rats were obviously lower than those in ovary intact rats.However,after indication with different doses of estrogen,CD34+ cells in peripheral blood and myocardium,the expression of SDF-1 and microvascular density were increased in ovariectomized rats with AMI,this effect was strongest especially in estrogen replacement therapy group.Conclusions Estrogen could improve the mobilization and homing of bone marrow stem cells into myocardium,increase capillary density and improve prognosis after AMI,and this mechanism could be mediated by promotion of expression of SDF-1 in myocardium.Moreover,the effect of estrogen replacement before AMI was better than estrogen therapy after AMI.