Steroid biosynthesis by zona glomerulosa-fasciculata cells in primary culture of guinea-pig adrenals.
Steroidogenesis was studied in guinea-pig glomerulosa-fasciculata cells maintained in primary culture for up to 7 days. The basal secretion which remained stable for the first 2 days in culture rapidly rose to reach a plateau on day 4 at levels 6-7-fold higher than those observed during the first 2 days of culture while the maximal response to ACTH in terms of cortisol and androstenedione secretion was fairly stable throughout the 7-day period. Exposure of glomerulosa-fasciculata cells to ACTH caused a stimulation of pregnenolone, 17-hydroxypregnenolone, progesterone, 17-hydroxyprogesterone, corticosterone, 11-deoxy-corticosterone, 11-deoxycortisol, cortisol, dehydroepiandrosterone, androstenedione, 11 beta-hydroxyandrostenedione and aldosterone while, after 48 h of incubation, a marked accumulation of end-products, namely cortisol and 11 beta-hydroxyandrostenedione, was observed. The half-maximal steroidogenic response to ACTH occurred at concentrations varying between 1.7 x 10(-11) and 1.1 x 10(-10) mol/l for the 12 steroids examined. Addition of 8-bromoadenosine 3', 5'-cyclic monophosphate stimulated steroid secretion in a dose-dependent manner. Maximal response to 8-bromoadenosine 3', 5'-cyclic monophosphate was obtained at 1 mmol/l, and no further rise of steroid secretion was observed after addition of ACTH. Incubation of glomerulosa-fasciculata cells with labeled corticosterone, cortisol and androstenedione indicates that only androstenedione can be converted into 11 beta-hydroxyandrostenedione, thus suggesting that this end-product is a good parameter of the C-19 steroid production by guinea-pig glomerulosa-fasciculata cells in primary culture. The present data confirm that guinea-pig glomerulosa-fasciculata cells in primary culture provide an interesting model for the study of the regulation of C-19 steroid formation by the adrenals.
Provencher
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P
Laval University Medical Centre, MRC Group in Molecular Endocrinology, Sainte-Foy, Quebec, Canada.
Lorrain
A
A
Bélanger
A
A
Fiet
J
J
D000241:Adenosine / Q000031:analogs & derivatives / Q000494:pharmacology; D000305:Adrenal Cortex Hormones / Q000096:biosynthesis*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000735:Androstenedione / Q000031:analogs & derivatives* / Q000096:biosynthesis; D000818:Animals; D002478:Cells, Cultured / Q000378:metabolism; D000242:Cyclic AMP / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D006854:Hydrocortisone / Q000096:biosynthesis; D008297:Male; D008954:Models, Biological; D015383:Zona Fasciculata / Q000187:drug effects / Q000378:metabolism*; D015384:Zona Glomerulosa / Q000187:drug effects / Q000378:metabolism*
D000305:Adrenal Cortex Hormones; C036038:8-bromoadenosine; D000735:Androstenedione; C003582:11-hydroxyandrostenedione; D000324:Adrenocorticotropic Hormone; D000242:Cyclic AMP; D000241:Adenosine; D006854:Hydrocortisone