Steroid metabolism by purified adult rat Leydig cells in primary culture

Journal Article · Mon Nov 01 00:00:00 EST 1982 · Steroids; (United States)

DOI:https://doi.org/10.1016/0039-128X(82)90074-5· OSTI ID:6965578

Browning, J Y; Tcholakian, R K; Kessler, M J; Grotjan, Jr, H E

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), Vol. 40:5
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
HYDROXYPREGNENONE
METABOLISM
STEROIDS
TESTOSTERONE
BIOSYNTHESIS
ANIMAL CELLS
BIOCHEMICAL REACTION KINETICS
CELL CULTURES
LABELLED COMPOUNDS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANDROGENS
ANDROSTANES
HORMONES
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
KETONES
KINETICS
ORGANIC COMPOUNDS
PREGNANES
REACTION KINETICS
STEROID HORMONES
SYNTHESIS
550501* - Metabolism- Tracer Techniques