title: Estrogen receptor translocation and replenishment in rat hypothalamus and pituitary gland after the application of catecholestrogen or nonsteroidal antiestrogen.
abstract: The time course of nuclear translocation of estrogen receptors and the replenishment of cytosolic receptor concentrations in the pituitary gland and hypothalamus of ovariectomized/adrenalectomized rats after the application of a high dose (0.1 mg/animal) of the catecholestrogens, 2-hydroxyethynylestradiol or 4-hydroxyethynylestradiol, was identical to that seen after the application of the monophenolic estrogen 17 alpha-ethynylestradiol. A distinctly different pattern of receptor distribution between these cell compartments was observed after the application of the nonsteroidal antiestrogen monohydroxytamoxifen (ICI 79,280) resulting in a prolonged depletion of cytosolic receptor concentrations. It therefore seems unlikely that the proposed antiestrogenic properties of 2-hydroxyestrogens are the result of a blocking of cytosolic receptor replenishment but may be explained by a reduced intrinsic nuclear activity of estrogen receptors complexed with 2-hydroxyestrogens.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004965:Estrogen Antagonists / Q000494:pharmacology*; D002393:Estrogens, Catechol / Q000494:pharmacology*; D004997:Ethinyl Estradiol / Q000494:pharmacology; D005260:Female; D007031:Hypothalamus / Q000378:metabolism*; D010902:Pituitary Gland / Q000378:metabolism*; D051381:Rats; D011960:Receptors, Estrogen / Q000378:metabolism*
chemical_list: D004965:Estrogen Antagonists; D002393:Estrogens, Catechol; D011960:Receptors, Estrogen; D004997:Ethinyl Estradiol