ACTH secretion in mouse pituitary tumor cells in culture: inhibition of CRF-stimulated hormone release by somatostatin.
Synthetic corticotropin-releasing factor (CRF) stimulates ACTH secretion in the clonal mouse pituitary cell strain AtT20/D16v (D16) in a dose-dependent manner with a half-maximal effect at 2X10(-9)M. A single dose of 5X10(-9)M CRF maximally stimulates the rate of ACTH secretion during the initial two hrs of treatment. During the period of maximal CRF stimulation intracellular hormone concentration declines progressively to a nadir at 4 hrs. During the ensuing 24 hrs of incubation intracellular hormone levels in CRF-stimulated cells increase gradually toward control values. Somatostatin (SRIF) inhibits the secretory response to CRF. This action of SRIF is dose-dependent with a half-maximal effect at 1X10(-9)M and results in decreased maximal ACTH secretion with little effect on the ED50 for CRF.
D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D002999:Clone Cells / Q000378:metabolism; D003346:Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D051379:Mice; D010911:Pituitary Neoplasms / Q000378:metabolism*; D013004:Somatostatin / Q000494:pharmacology*
D013004:Somatostatin; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone