Biosynthetic pathways for corticoids and androgen formation in human fetal adrenal tissue in vitro.

Abstract

Incubations [11] of minced human fetal adrenal adrenal tissue from 2 fetuses at 22 wk were performed for different periods of time with labeled pregnenolone, progesterone, 17.alpha.-hydroxy-progesterone and deoxycorticosterone (DOC). The order of magnitudes of enzyme activity when progesterone was used as a substrate and incubated with midterm fetal adrenals was 17.alpha.-hydroxylase, 21-hydroxylase and 16.alpha.-hydroxylase. Activity of 3.beta.-hydroxysteroid dehydrogenase and .DELTA.5-4 isomerase was almost negligible as compared to other enzymic activities. Similar biosynthetic pathways for adrenal corticoids formation were observed in human fetal adrenals as reported in human adults and animals; once progesterone was converted into DOC, further 17.alpha.-hydroxylation did not take place.