Effect of cyproheptadine, desmethylcyproheptadine, gamma-amino-butyric acid and sodium valproate on adrenocorticotrophin secretion by cultured pituitary tumour cells from three patients with Nelson's syndrome.
The effects of cyproheptadine, desmethylcyproheptadine, serotonin, gamma-amino-butyric acid (GABA) and sodium valproate were studied on ACTH secretion by cultured nonenzymatically dispersed pituitary tumour cells from three patients with Nelson's syndrome. Cyproheptadine (1-10 mumol/l) and desmethylcyproheptadine (1-10 mumol/l) suppressed ACTH secretion significantly (P less than 0.01), while serotonin (10 mumol/l) did not have a direct effect. Serotonin was also not able to reverse the (desmethyl)cyproheptadine-mediated inhibition of ACTH release. Sodium valproate and GABA did not exert a direct effect on hormone release by these cultured pituitary tumour cells. It is suggested that cyproheptadine-mediated inhibition of ACTH release in Nelson's syndrome might be effected by a direct non-serotonin-related effect on the pituitary tumour, while sodium valproate suppresses ACTH release by a suprahypophysial action.
D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D003533:Cyproheptadine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D005260:Female; D006801:Humans; D009347:Nelson Syndrome / Q000503:physiopathology*; D010911:Pituitary Neoplasms / Q000378:metabolism / Q000503:physiopathology*; D012701:Serotonin / Q000494:pharmacology*; D014635:Valproic Acid / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
C037546:desmethylcyproheptadine; D003533:Cyproheptadine; D012701:Serotonin; D005680:gamma-Aminobutyric Acid; D014635:Valproic Acid; D000324:Adrenocorticotropic Hormone