Pertussis toxin non-sensitive G protein mediates cholinergic stimulation for secretion of pancreastatin and somatostatin from QGP-1N cells.
To clarify the possible role of a guanine nucleotide-binding protein (G-protein) in the signal transducing system activated by carbachol, actions of carbachol on human pancreastatin producing cell line (QGP-1N) were compared with those of fluoride, a well-known activator of stimulatory (Gs) or inhibitory (Gi) G protein. 10(-5) M of carbachol as well as 20 mM of NaF stimulated secretion of pancreastatin and somatostatin and intracellular Ca2+ mobilization. These secretion and Ca2+ mobilization were not modified by pertussis toxin, an inhibitor of Gi protein. These results suggest that pancreastatin and somatostatin secretions from QGP-1N are regulated by acetylcholine through a muscarinic receptor coupled to the activation of polyphosphoinositide breakdown by a G protein, which appears to be fluoride sensitive but is other than a Gi-like protein.
Funakoshi
A
A
Department of Gastroenterology, National Kyushu Cancer Center, Fukuoka, Japan.
Tateishi
K
K
Tsuru
M
M
Kono
A
A
D002118:Calcium / Q000378:metabolism; D002217:Carbachol / Q000494:pharmacology*; D053379:Chromogranin A; D019204:GTP-Binding Proteins / Q000502:physiology*; D006801:Humans; D010187:Pancreatic Hormones / Q000378:metabolism*; D010190:Pancreatic Neoplasms; D037342:Pertussis Toxin; D015398:Signal Transduction; D012969:Sodium Fluoride / Q000494:pharmacology; D013004:Somatostatin / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D053379:Chromogranin A; D010187:Pancreatic Hormones; D010566:Virulence Factors, Bordetella; C050836:pancreastatin; D013004:Somatostatin; D002217:Carbachol; D012969:Sodium Fluoride; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D002118:Calcium