[Binding of a series of estrogens to the estrogen receptor system of guinea pig hypothalamo-hypophyseal structures].

The specificity of estrogen-receptor (ER) interaction was studied in cytosols of the adenohypophysis and anterior hypothalamus of guinea-pigs. The fundamental condition of active ER binding was shown to be the integrity of 17 beta- and C3-positions of the estradiol molecule excepting compounds with the combination of 17 beta-OH and 17 alpha-ethinyl groups. Significant differences were demonstrated in the affinity of the test compounds to ER systems of hypophyseal and hypothalamic cytosols.