2-Hydroxyestrone suppresses and 2-methoxyestrone augments the preovulatory prolactin surge in the cycling rat.
The nonuterotropic metabolite of estradiol, 2-hydroxyestrone, administered at noon of proestrus to four-day cycling rats, abolishes the preovulatory prolactin rise in a large percentage of animals tested. In animals synchronized with exogenous estradiol, 2-hydroxyestrone universally induced a long delay in the prolactin surge. The principal metabolite of 2-hydroxyestrone, 2-methoxyestrone, given at noon of proestrus, significantly augments the magnitude of the preovulatory prolactin rise possibly by inhibiting the formation of endogenous 2-hydroxyestrogens in the brain. The results obtained are consistent with the concept of a physiological function for 2-hydroxyestrogens as estrogen antagonists in the CNS.
D000818:Animals; D004958:Estradiol / Q000494:pharmacology; D004970:Estrone / Q000031:analogs & derivatives*; D005260:Female; D006894:Hydroxyestrones / Q000494:pharmacology*; D010060:Ovulation; D011247:Pregnancy; D011359:Proestrus / Q000187:drug effects; D011388:Prolactin / Q000097:blood*; D051381:Rats
D006894:Hydroxyestrones; D004970:Estrone; D004958:Estradiol; D011388:Prolactin; C003655:2-methoxyestrone; C024980:2-hydroxyestrone