内源性和外源性雌二醇对绵羊黄体溶解的作用

The Effects of Endogenous and Exogenous Estradiol on Luteolysis in Sheep

20只绵羊随机按双因子试验设计分为4个处理组,双因子为X-射线照射卵巢选择性破坏卵泡和埋植雌二醇。X-射线照射使发情周期黄体期延长,雌二醇使这种作用逆转。子宫内膜催产素受体浓度决定于黄体溶解发生的时间,即黄体溶解较早发生羊只子宫内膜催产素受体浓度低于黄体溶解发生较晚或尚未发生的羊只。催产素和PGFM均呈现明显的分泌波。雌二醇处理缩短PGFM峰值间隔时间、延长催产素峰值间隔时间,可能存在一种不依赖于催产素的PGF_(2α)释放;雌二醇对这种不依赖于催产素的PGF_(2α)释放有着重要作用。

Twenty ewes were randomly assigned to one of four treatment groups of a 2 x 2 factorially-designed experiment. The factors were destruction of follicles by selective irradiation of the ovaries and the administration of an estradiol implant. X-irradiation prolonged the lateal phase of the estrous cycle. This effect of irradiation was reversed by estradiol. Concentrations of oxytocin receptor observed on the 17th day depended on the time of luteolysis? the ewes whose luteolysis occurred earlier had lower concentrations of oxytocin receptor in endometrium than the ewes whose luteolysis occurred later or did not occur. Pulsatile release patterns in the secretion of oxytocin and PGFM were observed. Estradiol-treatment shortened the intervals between the PGFM peaks and prolonged the intervals between the oxytocin peaks. It seems possible that oxytocin-independent PGF2a release may exist under the conditions of this study. Estradiol may have an important role in regulating this oxytocin-independent PGF_2a release.