Steroid metabolism by purified adult rat Leydig cells in primary culture
To characterize Leydig cell steroidogensis, we examined the metabolism of (3H)pregnenolone (3 beta-hydroxy-5-pregnen-20-one) to androgens in the presence and absence of human chorionic gonadotropin (hCG) as a function of culture duration. Approximately 20-30% of the (3H)pregnenolone was converted to testosterone (17 beta-hydroxy-4-androsten-3-one) by purified Leydig cells at 0, 3 and 5 days (d) of culture. Androstenedione (4-androstene-3,17-dione) and dihydrotestosterone (17 beta-hydroxy-5 alpha-androstan-3-one) were also produced while on day 5 of culture, significant amounts of progesterone (4-pregnene-3,20-dione) were isolated. The delta 5 intermediates, 17-hydroxypregnenolone (3 beta, 17-dihydroxy-5-pregnen-20-one) and dehydroepiandrosterone (3 beta-hydroxy-5-androsten-17-one), accounted for less than 1% of substrate conversion, indicating a clear preference for Leydig cells to metabolize (3H)pregnenolone via the delta 4 pathway. On day 0 of culture, unidentified metabolites considered of predominately polar steroids while on day 5 of culture, the unidentified metabolites consisted of predominately nonpolar steroids. In the presence of hCG, (3H-pregnenolone metabolism did not differ from basal on day 0 or 3 of culture. HCG increased the conversion of pregnenolone to progesterone and 17-hydroxyprogesterone (17-hydroxy-4-pregnene-3,20-dione) on 5d. This suggests that Leydig cells cultured for 5d have decreased C17-20 desmolase activity or that hCG acutely stimulates 3 beta-hydroxysteroid dehydrogenase and delta 5-delta 5 isomerase activities.
- OSTI ID:
- 6965578
- Journal Information:
- Steroids; (United States), Journal Name: Steroids; (United States) Vol. 40:5; ISSN STEDA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Progesterone metabolism by the hypothalamus, pituitary, and uterus of the rat during pregnancy
Skin of the male African catfish, Clarias gariepinus: a source of steroid glucuronides
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ANDROGENS
ANDROSTANES
ANIMAL CELLS
BIOCHEMICAL REACTION KINETICS
BIOSYNTHESIS
CELL CULTURES
HORMONES
HYDROXY COMPOUNDS
HYDROXYPREGNENONE
ISOTOPE APPLICATIONS
KETONES
KINETICS
LABELLED COMPOUNDS
METABOLISM
ORGANIC COMPOUNDS
PREGNANES
REACTION KINETICS
STEROID HORMONES
STEROIDS
SYNTHESIS
TESTOSTERONE
TRACER TECHNIQUES
TRITIUM COMPOUNDS