Adrenocorticotropin(1-10) and -(11-24) promote adrenal steroidogenesis by different mechanisms.
ACTH1-10 and ACTH11-24 each elicit cortisol secretion submaximally in freshly dispersed or cultured beef adrenal cortical cells. The combination of ACTH1-10 and ACTH11-24 promotes cortisol release to the maximal level elicited by ACTH1-24. Maximal cortisol release by ACTH11-24, but not by ACTH1-24 or ACTH1-10, was enhanced by forskolin. The calcium channel blockers nifedipine and verapamil inhibited cortisol release by ACTH1-10, ACTH1-24 or ACTH11-24, suggesting calcium influx to be essential for steroid secretion regardless of the secretagogue. Vanadium, in a dose-dependent manner, inhibited cortisol secretion elicited by ACTH1-24 and ACTH1-10 but not that caused by ACTH11-24. These results suggest that there are at least two receptors mediating ACTH1-24-dependent steroid secretion. One class of receptor recognizes ACTH1-10 but not ACTH11-24 and is linked to the cAMP messenger pathway.
Li
Z G
ZG
Faculty of Medicine, Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Canada.
Park
D
D
LaBella
F S
FS
D000311:Adrenal Glands / Q000187:drug effects / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000032:analysis / Q000494:pharmacology / Q000502:physiology*; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D005576:Colforsin / Q000494:pharmacology; D003366:Cosyntropin / Q000032:analysis / Q000494:pharmacology / Q000502:physiology*; D000242:Cyclic AMP / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D006854:Hydrocortisone / Q000378:metabolism*; D008969:Molecular Sequence Data; D009543:Nifedipine / Q000494:pharmacology; D010446:Peptide Fragments / Q000032:analysis / Q000494:pharmacology / Q000502:physiology*; D011953:Receptors, Cyclic AMP / Q000378:metabolism / Q000502:physiology; D015290:Second Messenger Systems / Q000187:drug effects; D014639:Vanadium / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology
D010446:Peptide Fragments; D011953:Receptors, Cyclic AMP; D014639:Vanadium; D003366:Cosyntropin; D005576:Colforsin; C011393:ACTH (1-10); C034016:ACTH (11-24); D000324:Adrenocorticotropic Hormone; D014700:Verapamil; D000242:Cyclic AMP; D009543:Nifedipine; D006854:Hydrocortisone