title: Effect of oestradiol-17beta and progesterone on the metabolism of [1,2(-3)H] progesterone by the rabbit endometrium and myometrium.
abstract: The metabolism of [3H]progesterone in the rabbit endometrium and myometrium was studied in vitro. The major metabolities identified were 5alpha-pregnane-3,20-dione, 20alpha-hydroxypregn-4-en-3-one, 3beta-hydroxy-5alpha-preganan-20-one and 5alpha-pregnane-3beta,20alpha-diol. Other minor metabolites tentatively identified were 3alpha-hydroxy-5beta-pregnan-20-one,20alpha-hydroxy-5beta-pregnan-3-one and 5beta-pregnane-3alpha,20alpha-diol. The ability of the endometrium to metabolize progesterone on a unit weight bais was about 2.7 times that of the myometrium. The metabolism of [3H]progesterone in the rabbit uterus under the influnce of oestradiol-17beta and progesterone was studied. The ability of the oestradiol-treated rabbit uterus to metabolize progesterone was increased to 3.47 times that of the overiectomized control uterus, whereas the oestradiol-progesterone-treated rabbit uterus metabolized only 1.86 times that of the control. Study of the metabolism of progesterone with uterine subcellular preparations revealed that the 5alpha-reductase enzyme was present mainly in the nuclear fraction; 20alpha-hydroxysteroid dehydrogenase was found in the cytosol fraction and 3beta-hydroxysteroid dehydrogenase in the particulate fraction of the uterus. The metabolic pathways of progesterone in the rabbit uterine tissue are discussed.
mesh_terms: D000818:Animals; D004717:Endometrium / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D009215:Myometrium / Q000378:metabolism*; D011277:Pregnanediones / Q000032:analysis; D011280:Pregnanolone / Q000032:analysis; D011284:Pregnenolone / Q000032:analysis; D011374:Progesterone / Q000378:metabolism* / Q000494:pharmacology; D011817:Rabbits; D013347:Subcellular Fractions / Q000378:metabolism; D013997:Time Factors; D014599:Uterus / Q000378:metabolism*
chemical_list: D011277:Pregnanediones; D011374:Progesterone; D004958:Estradiol; D011284:Pregnenolone; D011280:Pregnanolone