雌激素缺乏引起雌性SD大鼠血小板激活

Platelet Activation Due to Estrogen Depletion in Female SD Rats

目的研究雌激素缺乏对雌性SD大鼠血小板聚集功能的影响及其与一氧化氮相关的作用机制。方法雌性SD大鼠随机分为假手术组、卵巢切除组以及卵巢切除补充雌激素组,分别施行假手术、卵巢切除术以及在卵巢切除术后第3天开始皮下注射补充雌激素,药物补充4周后处死动物,提取血清检测血清雌激素水平,提取富小板血浆测定血小板聚集功能,并用ELISA方法测定血浆中一氧化氮生物活性指标环磷酸鸟苷的水平。结果卵巢切除组雌性SD大鼠血清雌激素水平明显降低,雌激素补充使卵巢切除补充雌激素组动物的雌激素水平回复到假手术组状态。卵巢切除组雌性SD大鼠血小板聚集率显著升高;卵巢切除补充雌激素后血小板聚集率较前者明显回落,但仍高于假手术组聚集水平;血浆中环磷酸鸟苷水平在卵巢切除组显著下降,补充雌激素后血浆中环磷酸鸟苷水平与假手术组差异无显著性。结论雌激素缺乏会促进雌性SD大鼠的血小板聚集,其机制可能与血浆中一氧化氮/环磷酸鸟苷水平下降有关。

Aim To investigate whether estrogen deficiency may impact the platelet aggregation function in female SD rats and the underlying mechanisms relative to nitric oxide（NO）.Methods Female SD rats were randomly divided into three groups： sham,ovariectomy,and ovariectomy supplemented with estrogen group.Each of them received sham operation,ovariectomy or ovariectomy followed by estrogen supplementation respectively.Estrogen supplementation started 3 days after the ovariectomy and continued for the following 4 weeks,then the animals were sacrificed.The serum was obtained to perform the estrogen assay.The platelet-rich plasma was collected to measure its platelet aggregation ability,and to detect plasma cGMP（Guanosine 3,5-cyclic monophosphate）,the NO bioactive index,via the method of ELISA.Results The serum estrogen level in ovariectomized female SD rats was much lower than that in shamed animals,estrogen supplementation effectively restored the ovariectomized animals＇ serum estrogen.The platelets aggregation in ovariectomized rats was remarkably higher than that in shamed animals,estrogen supplementation could lower the platelets aggregation ability,though not to the sham level.The plasma cGMP level in the ovariectomized rats was significantly lower than that of shamed animals,estrogen supplementation may remarkably enhance the plasma cGMP,to a level in keeping with the sham group.Conclusion Lack of estrogen may boost the platelets aggregation in female SD rats,the mechanism might be relative to the down-regulation of NO/cGMP by estrogen depletion.