Cantineau R, Kremers P, De Graeve J, Gielen JE, Lambotte R. Aromatization of 15 alpha and 16 alpha hydroxylated androgens in the human placental using [1,2-3H]-substrates.
JOURNAL OF STEROID BIOCHEMISTRY 1982;
16:157-63. [PMID:
7078154 DOI:
10.1016/0022-4731(82)90162-5]
[Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
This in vitro study reports data on the aromatization of [1,2-3H]-C19 steroids in the human term placenta [androstenedione (III), testosterone (IV), 15 alpha-hydroxy-androstenedione (V), 15 alpha-hydroxy-testosterone (VI), 16 alpha-hydroxy-androstenedione (VII)]. The hydroxylated androgens were microbiologically synthesized from commercially radiolabelled [1,2-3H]-androstenedione and testosterone. Androstenedione and testosterone were good substrates for the human placental aromatase (low Km values, high Vmax); they strongly inhibited the 15 and 16 hydroxylated androgens aromatizations. On the other hand, these hydroxylated compounds acted as poor substrates and were only non-competitive inhibitors of the androstenedione and testosterone aromatizations. However, 15 alpha-hydroxy-androstenedione could not be disregarded as a potential precursor of 15 alpha-hydroxylated estrogens in the human placenta.
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