ONTOGENY OF 3-BETA-HYDROXYSTEROID DEHYDROGENASE DELTA-5-DELTA-4 ISOMERASE (3-BETA-HSD) IN HUMAN ADRENAL-GLAND PERFORMED BY IMMUNOCYTOCHEMISTRY

Human foetal adrenal plays a major role in the synthesis and secretion of steroids which are essential to several physiological events during foetal development. Since 3β-hydroxysteroid dehydrogenase 5-ene-4-ene isomerase (3β-HSD) is involved in the biosynthesis of all classes of hormonal steroids, namely progesterone, glucocorticoids, mineralocorticoids, androgens and estrogens, knowledge of the ontogeny of 3β-HSD should lead to a better understanding of steroidogenesis in the foetal adrenal. Polyclonal antibodies raised against purified human placental 3β-HSD were used to localize the enzyme in 22-week, 28-week, and term foetal adrenals as well as in the adrenals of 2-month-, 8-month- and 2-year-old infants. 3β-HSD has been identified in the outer cortex, neocortex and zona glomerulosa zone of foetal adrenal, respectively. In 2-month- and 8-month-old infant adrenals, the enzyme was localized in the zona glomerulosa and zone fasciculata while in 2-year-old infants, the immunoreaction was observed also in the zona reticularis, the medulla being devoid of any reaction. © 1990.