雌激素对大鼠血小板聚集性的影响

Effects of estrogen on platelet adhesiveness in female rats

目的研究大鼠人工绝经及补充雌激素（ｅｓｔｒｏｇｅｎ，Ｅ）后血小板聚集性的变化及其部分机制。方法将２４只ＳＤ雌性大鼠随机分为３组：假手术组、单纯去势组、去势＋补充雌激素组。观察其血小板聚集性、一氧化氮（Ｎｉｔｒｉｃ ｏｘｉｄｅ， ＮＯ）、前列环素（Ｐｒｏｓｔａｃｙｃｌｉｎ，ＰＧＩ_２）、血栓烷 Ａ_２（Ｔｈｒｏｍｂｏｘａｎｅ Ａ_２ ＴＸＡ_２）及血栓烷Ａ_２与前列环素的比值（ＴＸＡ_２／ＰＧＩ_２）的变化。结果单纯去势组大鼠血小板聚集性较假手术组明显增加，去势＋补充雌激素组较单纯去势组下降；单纯去势后雌性大鼠ＴＸＡ_２／ＰＧＩ_２上升．补充雌激素组下降；去势后雌性大鼠ＮＯ明显降低，补充雌激素后升高。结论绝经后补充雌激素可通过降低ＴＸＡ_２／ＰＧＩ_２、升高ＮＯ抑制血小板聚集，对绝经后妇女冠心病有防治作用。

Objective To study platelet adhesiveness after ovariectomy with estrogen replacement therapy and explore the mechanism. Mathods Twentyfour female rats were randomly divided into 3 groups (sham-ovariectomized, ovariectomy and ovariectomy with estrogen replacement therapy) and corresponding treatment was administered. The platetet adhesiveness was observed and plasma levels of NO, PGI_2, TXA_2 and the ratio of TXA_2 to PGI_2 determined. Results Platelet adhesiveness in the group subjected to ovariectomy with estrogen replacement therapy was lower than that of the ovariectomy group, and the latter was markedly higher than that of the sham-ovariectomized group. The ratio of TXA_2 to PGI_2 balance was increased in ovariectomy group, and decreased in group of ovariectomy with estrogen replacement therapy. Plasma levels of NO was lower in ovariectomy group and higher in the group of ovariectomy with estrogen replacement therapy. Conclusion After menopausal, inhibition of platelet adhesiveness by decreasing ratio of TXA_2 to PGI_2 and increasing NO level are beneficial for the prevention of coronary artery diseases.