Induction by progesterone of a sexual dimorphism of estrogen uptake by anterior pituitary cells in situ.
The effects of progesterone pretreatment on in vivo 3H-estrogen uptake by five anterior pituitary cell types was analyzed by means of a quantitative autoradiographic-immunocytochemical technique. Male and female rats castrated for 14 days show nuclear concentration of label in all five cell types one h after injection of 3H-estradiol, whether progesterone treated or not. The order of labeling intensity is gonadotropes greater than or equal to lactotropes = somatotropes greater than thyrotropes = corticotropes. Progesterone treatment induces a dramatic sexual dimorphism in estrogen uptake; it significantly increases 3H-estrogen uptake in all female cell types. In males, progesterone decreases uptake in gonadotropes while not altering uptake in other cell types.
D000818:Animals; D002369:Castration; D002467:Cell Nucleus / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D008297:Male; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D011374:Progesterone / Q000494:pharmacology*; D051381:Rats; D012737:Sex Factors
D011374:Progesterone; D004958:Estradiol