Aten R F, Weinberger M J, Eisenfeld A J
Endocrinology. 1978 Feb;102(2):433-42. doi: 10.1210/endo-102-2-433.
Following in vivo ethinyl estradiol (EE2) administration (100 microgram sc) to adult female rats, the estradiol-specific binding sites (ESBS) of liver cytosol were markedly reduced at 30 and 60 min. The reduction at 30 min was to one-quarter of that found in rats treated with vehicle alone. Coincident with this reduction, nuclear ESBS were increased. The ESBS of partially purified cytosol and of dense sucrose-purified nuclei were determined by gel filtration after incubations with tritiated estradiol using exchange assay conditions. An elevated temperature during the exchange assay incubations was necessary to demonstrate most of the ESBS in purified nuclei of EE2-treated rats and suggested that estrogens are attached at these sites. Following administration of 5 microgram EE2, the decrease in cytosol ESBS and the increase in nuclear ESBS were smaller. In contrast, 5 microgram EE2 was as effective as 100 microgram EE2 in substantially increasing the ESBS observed in uterine nuclear fractions. The low level of ESBS found in whole brain purified nuclei was unchanged by 100 microgram EE2 administration. The steroid specificity and proteolytic enzyme sensitivity of the purified nuclear ESBS of treated rats were similar to that of the partially purified cytosol ESBS of rats treated with vehicle alone. The data are consistent with the ESBS being estrogen receptor proteins which translocate from the liver cytosol to the nucleus after estrogen administration in vivo.
给成年雌性大鼠皮下注射100微克乙炔雌二醇（EE2）后，肝胞液中的雌二醇特异性结合位点（ESBS）在30分钟和60分钟时显著减少。30分钟时的减少量降至单独给予赋形剂处理的大鼠的四分之一。与此减少同时发生的是，核ESBS增加。在使用交换分析条件与氚化雌二醇孵育后，通过凝胶过滤测定部分纯化的胞液和经蔗糖密度梯度离心纯化的细胞核的ESBS。在交换分析孵育过程中升高温度对于证明EE2处理大鼠纯化细胞核中的大多数ESBS是必要的，这表明雌激素附着在这些位点。给予5微克EE2后，胞液ESBS的减少和核ESBS的增加较小。相比之下，5微克EE2在显著增加子宫核组分中观察到的ESBS方面与100微克EE2一样有效。给予100微克EE2后，全脑纯化细胞核中发现的低水平ESBS没有变化。处理大鼠纯化核ESBS的类固醇特异性和对蛋白水解酶的敏感性与单独给予赋形剂处理的大鼠的部分纯化胞液ESBS相似。这些数据与ESBS是雌激素受体蛋白一致，该蛋白在体内给予雌激素后从肝胞液转运到细胞核。
