title: The conversion of delta 5-steriods to testosterone and androstenedione in human amniotic epithelium in vitro.
abstract: 3 beta-Hydroxysteroid dehydrogenase / delta 5-4 isomerase activity was demonstrated in the human amniotic epithelium from the first trimester of pregnancy. The evidence was based on the in vitro formation of [4-14C] testosterone and [4-14C] androstenedione from [4-14C] 5-androstenediol and [4-14CA1 DEHYDROEPIANDROSTERONE, RESPECTIVELY. The activity of the enzyme studied in age dependent, reaching a maximum in the 8th-9th week of pregnancy and decreasing to negligible values at the end of the second trimester of gestation.
mesh_terms: D000650:Amnion / Q000378:metabolism*; D000735:Androstenedione / Q000096:biosynthesis*; D004848:Epithelium / Q000201:enzymology; D005260:Female; D006801:Humans; D007535:Isomerases / Q000378:metabolism*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D013251:Steroid Isomerases / Q000378:metabolism*; D013739:Testosterone / Q000096:biosynthesis*
chemical_list: D013739:Testosterone; D000735:Androstenedione; D007535:Isomerases; D013251:Steroid Isomerases