1. Studies on the Metabolism of Steroids in the Foetus.
- Author
-
Plasse, Jean-Claude and Lisboa, Belisário Penna
- Subjects
- *
STEROIDS , *CHROMATOGRAPHIC analysis , *FETUS , *LIVER , *ANDROSTENEDIONE , *TESTOSTERONE , *BIOCHEMISTRY - Abstract
Biosynthesis and site of formation of epitestosterone in the human foetus was investigated by incubation of androstenedione with subcellular fractious of mid-gestational foetal liver. Testesterone and epitestosterone were purified by thin-layer chromatography and resolved by gas-liquid chromatography. Epitestosterone (and testosterone) were identified by gas chromatography-mass spectrometry as silyl ether and methoximesilyl ether derivatives. The ratio testosterone : epitestosterone found in the incubations was about 20:1. Both 17β- and 17α-hydroxysteroid oxidoreductase activities were found in the 105000×g microsome fraction as well as in the cytosol fraction. It may be concluded that the human foetal liver is one of the sources of production of epitestosterone, and that androstenedione is one of its precursors. The possibility that androstenedione and epitestosterone are precursors of maternal urinary 17α-hydroxyphenolic steroids during pregnancy is discussed. [ABSTRACT FROM AUTHOR]
- Published
- 1973
- Full Text
- View/download PDF