title: Oxygen dependence of oestrogen production by human placental microsomes and cultured choriocarcinoma cells.
abstract: The oxygen dependence of oestrogen (oestrone and 17 beta-oestradiol) formation from androstenedione and testosterone was studied in term human placental microsomes and in cultured human choriocarcinoma cells (BeWo line). Incubations were performed under various steady-state oxygen concentrations and the production of oestrone and 17 beta-oestradiol quantitated by specific radioimmunoassays. The aromatization of C19-steroids by both placental microsomes and choriocarcinoma cells was shown to be oxygen dependent over a wide range of O2 concentrations. The results indicate that placental oxygenation may be a critical factor in determining oestrogen production in vivo. Therefore, impaired oestrogen biosynthesis due to hypoxia could be an important factor in a variety of physiological and pathological conditions.
mesh_terms: D000735:Androstenedione / Q000378:metabolism; D001141:Aromatase / Q000378:metabolism*; D002460:Cell Line; D002822:Choriocarcinoma / Q000201:enzymology*; D004958:Estradiol / Q000096:biosynthesis; D004967:Estrogens / Q000096:biosynthesis*; D004970:Estrone / Q000096:biosynthesis; D005260:Female; D006801:Humans; D008861:Microsomes / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D010100:Oxygen / Q000494:pharmacology*; D010920:Placenta / Q000187:drug effects / Q000201:enzymology*; D011247:Pregnancy; D013739:Testosterone / Q000378:metabolism; D014594:Uterine Neoplasms / Q000201:enzymology*
chemical_list: D004967:Estrogens; D004970:Estrone; D013739:Testosterone; D000735:Androstenedione; D004958:Estradiol; D009249:NADP; D010088:Oxidoreductases; D001141:Aromatase; D010100:Oxygen