Differential depletion of cytoplasmic high affinity oestrogen receptors after the in vivo administration of the antioestrogens, clomiphene, MER-25 and tamoxifen.
1 The in vivo actions of the oestrogen antagonists, MER-25 and tamoxifen upon the cytosol oestrogen receptors prepared from amygdala, hypothalamus, pituitary and uterus of rats were studied 24 h after drug administration. 2 There was a dose-related depletion of cytosol oestrogen receptors. However, the uterine and pituitary receptors were consistently affected at a lower dose than were those from the brain. 3 The ratios of the combined central ED50 to the combined peripheral ED50 were clomiphene 169 greater than MER-25 19.2 greater than tamoxifen 2.13. 4 The receptor changes were not related to biological activity monitored by serum luteinizing hormone levels and uterotrophic response. 5 The possible role of these drug effects in the induction of ovulation and future developments are discussed.
D000818:Animals; D002369:Castration; D002996:Clomiphene / Q000494:pharmacology*; D003593:Cytoplasm / Q000378:metabolism; D004965:Estrogen Antagonists / Q000494:pharmacology*; D004978:Ethamoxytriphetol / Q000494:pharmacology*; D000431:Ethanol / Q000031:analogs & derivatives*; D005260:Female; D066298:In Vitro Techniques; D007986:Luteinizing Hormone / Q000097:blood; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011960:Receptors, Estrogen / Q000187:drug effects*; D013629:Tamoxifen / Q000494:pharmacology*; D014599:Uterus / Q000187:drug effects
D004965:Estrogen Antagonists; D011960:Receptors, Estrogen; D013629:Tamoxifen; D002996:Clomiphene; D000431:Ethanol; D004978:Ethamoxytriphetol; D007986:Luteinizing Hormone