Armstrong E G, Tobert J A, Talley D J, Villee C A
Endocrinology. 1977 Nov;101(5):1545-51. doi: 10.1210/endo-101-5-1545.
A specific cytoplasmic progesterone receptor has been identified and quantified in the deciduomata of the pseudopregnant rat. The receptor had a sedimentation coefficient of 6-7S on sucrose density gradients and was inactivated by proteolytic enzymes, sulfhydryl blocking agents and elevated temperature. The equilibrium association constant for the binding of progesterone by the deciduomal receptor was determined to be approximately 10(9)M-1. The concentrations of progesterone receptor sites in cytosols prepared from deciduomata on day 3 and 5 of decidualization were 3.4 +/- 0.3 X 10(-10)M and 3.6 +/- 0.4 X 10(10)M, respectively, when normalized to a protein concentration of 1 mg/ml. These concentrations of progesterone receptor sites were similar to that measured in the uterine cytosol of estrous rats or in the contralateral untreated uterine horn of rats undergoing decidualization. Following day 5 of decidualization the concentrations of progesterone receptor sites decreased linearly so that by day 7 the concentration was approximately one-half that at days 3 and 5. The physiological significance of the progesterone receptor and the decrease in its concentration with time are discussed with regard to their influence on the decidualization reaction.
在假孕大鼠的蜕膜中已鉴定并定量了一种特定的细胞质孕酮受体。该受体在蔗糖密度梯度上的沉降系数为6 - 7S，并且会被蛋白水解酶、巯基阻断剂和高温灭活。蜕膜受体与孕酮结合的平衡缔合常数测定约为10(9)M-1。当归一化为蛋白质浓度1mg/ml时，在蜕膜化第3天和第5天从蜕膜制备的胞质溶胶中孕酮受体位点的浓度分别为3.4 +/- 0.3 X 10(-10)M和3.6 +/- 0.4 X 10(10)M。这些孕酮受体位点的浓度与在动情期大鼠子宫胞质溶胶或正在进行蜕膜化的大鼠对侧未处理子宫角中测得的浓度相似。在蜕膜化第5天后，孕酮受体位点的浓度呈线性下降，因此到第7天时，浓度约为第3天和第5天的一半。讨论了孕酮受体的生理意义及其浓度随时间的下降对蜕膜化反应的影响。
