title: Atrial natriuretic peptide effects in AtT-20 pituitary tumour cells.
abstract: Whether atrial natriuretic peptide (ANP)-evoked inhibition of corticotrophin-releasing factor (CRF)-stimulated ACTH secretion was also manifest in ACTH secreting AtT-20 pituitary tumour cells was investigated. ANP stimulated increases in cGMP accumulation at concentrations of the peptide above 10(-8) M which indicates the presence of the ANP receptors on these cells. CRF stimulated a concentration-dependent increase in ACTH secretion from AtT-20 cells which was unaffected by ANP, 8-bromo-cGMP, or sodium nitroprusside (SNP). Calcium stimulated a concentration-dependent increase in ACTH secretion from electrically permeabilised cells which was unaffected by co-incubation with cGMP but potentiated by cAMP. These results reveal the presence of ANP receptors on AtT-20 cells but suggest that an incomplete expression of the stimulus-secretion coupling mechanisms for ANP, at some point after cGMP production, prevents the effects of natriuretic peptides upon ACTH secretion being manifest in these cells.
authors.affiliation: Molecular Endocrinology Group, School of Biological and Medical Sciences, University of St. Andrews, UK.
authors.forename: A F
authors.initials: AF
authors.lastname: Gilkes
authors.forename: K B
authors.initials: KB
authors.lastname: MacKay
authors.forename: G
authors.initials: G
authors.lastname: Cramb
authors.forename: S B
authors.initials: SB
authors.lastname: Guild
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000324:Adrenocorticotropic Hormone / Q000378:metabolism*; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology; D002463:Cell Membrane Permeability; D003346:Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D051379:Mice; D009599:Nitroprusside / Q000494:pharmacology; D010911:Pituitary Neoplasms / Q000378:metabolism / Q000473:pathology*; D017461:Receptors, Atrial Natriuretic Factor / Q000187:drug effects / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D009599:Nitroprusside; C016276:8-bromocyclic GMP; D009320:Atrial Natriuretic Factor; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D000242:Cyclic AMP; D017461:Receptors, Atrial Natriuretic Factor; D006152:Cyclic GMP; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine