title: Activation of Na+ channels in GH3 cells and human pituitary adenoma cells by PACAP.
abstract: The effects of pituitary adenylate cyclase activating polypeptide (PACAP) on ion channels were examined in GH3 cells human pituitary adenoma cells. In GH3 cells, PACAP-38 (10-9 M) reversibly activated tetrodotoxin-sensitive NA+ channels but had little effect on nicardipine-sensitive Ca2+ channels. PACAP-induced increase in Na+ currents was inhibited by PACAP (6-38), a specific PACAP receptor antagonist, and Rp-cAMPs, an inhibitor for protein kinase A, and mimicked by 8-bromo-cAMP. In human pituitary adenoma cells, PACAP also activated tetrodotoxin-sensitive Na+ channels and growth hormone secretion. These results suggest the possibility that PACAP can activate voltage-gated Na+ channels via adenylate cyclase-protein kinase A pathway in the pituitary.
authors.affiliation: Department of Medicine, Shimane Medical University, Izumo, Japan. kunio@shimane-med.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Koshimura
authors.forename: Y
authors.initials: Y
authors.lastname: Murakami
authors.forename: M
authors.initials: M
authors.lastname: Mitsushima
authors.forename: T
authors.initials: T
authors.lastname: Hori
authors.forename: Y
authors.initials: Y
authors.lastname: Kato
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000236:Adenoma; D002460:Cell Line; D019382:Human Growth Hormone / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D009479:Neuropeptides / Q000494:pharmacology*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D015222:Sodium Channels / Q000187:drug effects / Q000378:metabolism*; D013779:Tetrodotoxin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: C495401:ADCYAP1 protein, human; D009479:Neuropeptides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D015222:Sodium Channels; D019382:Human Growth Hormone; D015124:8-Bromo Cyclic Adenosine Monophosphate; D013779:Tetrodotoxin