Hoshiai H, Takahashi K, Furuhashi N, Wada Y, Uehara S, Suzuki M
Tohoku J Exp Med. 1982 Feb;136(2):195-202. doi: 10.1620/tjem.136.195.
The variation of cytoplasmic estrogen receptor in the mammary gland during pregnancy and puerperium was studied to determine the role of estrogens in the mechanism of lactation. Cytosol estrogen receptors from rat mammary glands were incubated with 3H-estradiol, and the free estradiol was removed using dextran-coated charcoal. The maximum number of binding sites in the cytosol was estimated from saturation curves and Scatchard analysis. During pregnancy the number of binding sites was relatively low (2.5 to 3.8 pmoles per mg protein), but increased after delivery to 7.8 pmoles per mg protein. The number of estrogen binding sites in the mammary glands of lactating rats five days after delivery was at the same level as on the day of delivery. However, at ten days after delivery the number of binding sites increased markedly to 58.9 pmoles per protein. The number of estrogen-binding sites in the mammary glands of lactating rats was decreased by castration and by the injection of testosterone or 2-bromoergocriptine. There appeared no competition by testosterone, progesterone or cortisol with estrogen receptors in the mammary gland.
为确定雌激素在泌乳机制中的作用，研究了孕期和产褥期乳腺中细胞质雌激素受体的变化。将大鼠乳腺的胞质雌激素受体与³H-雌二醇一起孵育，并用葡聚糖包被的活性炭去除游离雌二醇。通过饱和曲线和Scatchard分析估算胞质中结合位点的最大数量。孕期结合位点数量相对较低（每毫克蛋白质2.5至3.8皮摩尔），但分娩后增加到每毫克蛋白质7.8皮摩尔。分娩后五天，泌乳大鼠乳腺中雌激素结合位点的数量与分娩当天处于同一水平。然而，分娩后十天，结合位点数量显著增加至每毫克蛋白质58.9皮摩尔。阉割以及注射睾酮或2-溴麦角隐亭可使泌乳大鼠乳腺中雌激素结合位点的数量减少。在乳腺中，未发现睾酮、孕酮或皮质醇与雌激素受体存在竞争。
