Owen F J, Cake M H, Bradshaw S D
J Endocrinol. 1982 Apr;93(1):17-24. doi: 10.1677/joe.0.0930017.
A progesterone receptor system, with a high specificity for progestins, was detected in the uterine tissue of the marsupial, Setonix brachyurus (quokka), using the synthetic progestin 17 alpha, 21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione (R5020). The apparent equilibrium dissociation constant of the ligand binding to the cytosolic component was 2.2 nmol/l, and to the nuclear component 4.8 nmol/l. Significant loss of binding ability of the receptor occurred when cytosol was pretreated with dextran-coated charcoal. All binding studies were performed, therefore, in the presence of endogenous steroid which was demonstrated to affect the dissociation constant but have no effect on the estimation of the concentration of binding sites. Cytosolic binding was increased sixfold by oestradiol-17 beta treatment in vivo, and the translocation of the bound complex into the nucleus was effected by progesterone. It is suggested that the binding component described plays a role in the action of progesterone on the uterine tissue of the quokka.
利用合成孕激素17α，21 - 二甲基 - 19 - 去甲 - 4,9 - 孕二烯 - 3,20 - 二酮（R5020），在有袋动物短尾矮袋鼠（Setonix brachyurus）的子宫组织中检测到了一种对孕激素具有高度特异性的孕激素受体系统。配体与胞质成分结合的表观平衡解离常数为2.2 nmol/l，与核成分结合的表观平衡解离常数为4.8 nmol/l。用葡聚糖包被的活性炭预处理胞质溶胶时，受体的结合能力显著丧失。因此，所有结合研究均在存在内源性类固醇的情况下进行，已证明内源性类固醇会影响解离常数，但对结合位点浓度的估计没有影响。体内用17β - 雌二醇处理可使胞质结合增加六倍，而孕激素可使结合复合物向核内转运。提示所描述的结合成分在孕激素对短尾矮袋鼠子宫组织的作用中发挥作用。
