title: Conversion, in vitro, of (7n-3H) testosterone to estrone and estradiol-17beta and their 3-sulfate conjugate by the guinea-pig placenta.
abstract: Different cellular fractions of guinea-pig placenta were incubated  in the presence of (7n-3H) testosterone. Microsomal aromatization of 3H-testosterone into estrone and estradiol-17beta was demonstrated in the presence of NADPH. The predominance of estrone after incubation with 17beta-hydroxylated precursors, (7n-3H) testosterone and (6,7-3H) estradiol-17beta, indicate that there is a microsomal 17beta-hydroxysteroid dehydrogenase activity. In this report, cytosolic sulfurylation of estrogens is demonstrated. This latter activity represents a quite original characteristic of the placental metabolism of estrogens in guinea-pigs. In contrast with the human placenta where there is considerable sulfatase activity, the guinea-pig placenta can sulfurylate estrogens.
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000818:Animals; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D004958:Estradiol / Q000096:biosynthesis*; D004970:Estrone / Q000096:biosynthesis*; D005260:Female; D006168:Guinea Pigs / Q000378:metabolism*; D066298:In Vitro Techniques; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D013431:Sulfates / Q000378:metabolism; D013739:Testosterone / Q000378:metabolism*
chemical_list: D013431:Sulfates; D004970:Estrone; D013739:Testosterone; D004958:Estradiol; D015067:17-Hydroxysteroid Dehydrogenases