[Action of an antiestrogen agent, tamoxifen on the mammae of ovariectomized rats].
We have been studying the estrogen and antiestrogen action of tamoxifen and of clomifen on the development and secretion of acini and of the galactophore canals of the mammary gland. The ICI (50 or 200 microgram) has no effect : the very strong dose of 1 mg gives a light stimulation of the acini secretion which can be compared to that of light doses of clomifen (20 or 50 microgram) or of estradiol (0.25 microgram). Only 10 microgram of estradiol alone allow the development, the opening and secretion of acini. With 20 microgram, this action is more apparent, not only on the often dilated acini, but also on the canals. Administered along with 20 microgram of estradiol, tamoxifen is slightly antagonist with 50 microgram, strongly antagonist with 200 microgram, and completely antagonist with 1 mg. 50 microgram of clomifen are inefficient ; it is synergetic if the treatment starts and is over 4 days before the estradiol treatment.
D000818:Animals; D002369:Castration; D002996:Clomiphene / Q000494:pharmacology; D004965:Estrogen Antagonists; D005260:Female; D008321:Mammary Glands, Animal / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D013267:Stilbenes / Q000494:pharmacology*; D013629:Tamoxifen / Q000494:pharmacology*
D004965:Estrogen Antagonists; D013267:Stilbenes; D013629:Tamoxifen; D002996:Clomiphene
Action d'un anti-estrogène, le tamoxifène, sur les mamelles de la ratte ovariectomisée.