[Combined effects of estradiol, progesterone and tamoxifen on the synthesis of specific proteins in the oviduct of the chicken].
Tamoxifen, an antiestrogen with non estrogenic effect on growth, differentiation and egg white protein synthesis in the chick oviduct, has been administered together with progesterone. In estrogen differentiated, hormone withdrawn animals, biochemical and ultrastructural data indicated that the combined treatment with progesterone plus tamoxifen increased conalbumin (+ 100%) and ovalbumin (+ 30%) more than progesterone alone, and displayed estrogen-like growth promoting properties (+ 50% in DNA content/oviduct). Moreover, administered with progesterone and estradiol, tamoxifen lost part of its antiestrogenic activity. No obvious change of progesterone clearance from the blood or progesterone metabolism was recorded. The presence in amounts similar to those resulting in optimal activity when injected alone (greater than or equal to 1mg/kg) was necessary to obtain progesterone plus tamoxifen effets. The simultaneous presence of progesterone and tamoxifen was required in order to observe their combined effects and it was observed that progesterone did not have to commit cells on which tamoxifen could subsequently act. In the immature "undifferentiated" oviduct, contrary to tamoxifen and progesterone alone, their combination induced cytodifferentiation of tubular gland cells synthesizing conalbumin and ovalbumin, an event never observed before in the absence of estrogen. These results support the suggestion that the hormonal milieu interferes with antiestrogen action.
D000818:Animals; D002645:Chickens; D004357:Drug Synergism; D004527:Egg Proteins / Q000096:biosynthesis*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D010057:Oviducts / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D011374:Progesterone / Q000494:pharmacology*; D013268:Stimulation, Chemical; D013629:Tamoxifen / Q000494:pharmacology*
D004527:Egg Proteins; D013629:Tamoxifen; D011374:Progesterone; D004958:Estradiol
Effets combinés de l'oestradiol, de la progestérone et du tamoxifen sur la synthèse des protéines spécifiques dans l'oviducte de poulet.