title: Effect of adrenocorticotrophin on cortisol and androstenedione secretion from dispersed cells of guinea-pig adrenal zonae fasciculata and reticularis.
abstract: We have studied cortisol and androstenedione secretion by dispersed cells of the outer zona fasciculata (ZF) plus zona glomerulosa, and the inner zona reticularis (ZR) plus medulla of the guinea-pig adrenal. The ZF and ZR were microdissected apart, the cells dispersed and incubated (200 000 cells/ml) for 90 min in the presence of adrenocorticotrophin (ACTH; 500 ng/l), dibutyryl cyclic AMP (dbcAMP; 1 mmol/l), pregnenolone, 17-hydroxypregnenolone, 17-hydroxyprogesterone, 11-deoxycortisol and 21-deoxycortisol. The steroid concentrations were 5-25 mumol/l. Cortisol secretion was assayed by radioimmunoassay. There was no detectable cortisol secretion (less than 50 nmol/l) from the ZR in the controls (no additive) or after dbcAMP stimulation. Adrenocorticotrophin-stimulated cortisol secretion was also low (range less than 50-340 nmol/l). In contrast the ZF secreted 177-379 (control), 828-2052 (dbcAMP) and 2863-9735 (ACTH) nmol cortisol/l. There was no detectable (i.e. less than 2 nmol/l) cAMP production by ZR or ZF either basally (no ACTH) or after ACTH stimulation (500 ng/l). Challenge of the ZR cells with each cortisol precursor steroid (5 mumol/l) increased (P less than 0.05) cortisol secretion over that seen with the corresponding basal and ACTH-stimulated controls. Thus pregnenolone, 17-hydroxypregnenolone, 17-hydroxyprogesterone, 11-deoxycortisol and 21-deoxycortisol (converted directly to cortisol by 21-hydroxylase) gave rise to (mean +/- S.D., n = 4) 406 +/- 86, 680 +/- 180, 1307 +/- 111, 1141 +/- 234 and 3160 +/- 419 nmol cortisol/l respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D006907:17-alpha-Hydroxypregnenolone / Q000494:pharmacology; D000302:Adrenal Cortex / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000735:Androstenedione / Q000378:metabolism*; D000818:Animals; D001835:Body Weight; D003994:Bucladesine / Q000494:pharmacology; D002478:Cells, Cultured; D003350:Cortodoxone / Q000494:pharmacology; D006168:Guinea Pigs; D006854:Hydrocortisone / Q000378:metabolism*; D006908:Hydroxyprogesterones / Q000494:pharmacology; D007536:Isomerism; D008297:Male; D009929:Organ Size; D011284:Pregnenolone / Q000494:pharmacology
chemical_list: D006908:Hydroxyprogesterones; C030228:11-hydroxyprogesterone; D006907:17-alpha-Hydroxypregnenolone; D000735:Androstenedione; D003994:Bucladesine; C003556:21-deoxycortisol; D011284:Pregnenolone; D000324:Adrenocorticotropic Hormone; D003350:Cortodoxone; D006854:Hydrocortisone