The calcium agonist Bay K 8644 stimulates secretion from a pituitary cell line.
The dihydropyridine calcium agonist Bay K 8644 acts in a dose-dependent manner to increase prolactin secretion from the GH4C1 pituitary cell line. Enhanced secretion was observed at agonist concentrations as low as 10 nM. In the continued presence of Bay K 8644 secretion remained elevated for at least 30 min. The effect of the agonist was Ca2+-dependent and competitively antagonized by dihydropyridine antagonists. Apparently Bay K 8644 acts at the dihydropyridine binding site associated with GH4C1 Ca2+ channels to enhance Ca2+ influx and stimulate secretion from these cells. This is the first report demonstrating that the newly discovered Ca2+ agonist can, by itself, stimulate secretion from a cell.
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002460:Cell Line; D002999:Clone Cells; D007700:Kinetics; D051379:Mice; D009539:Nicotinic Acids / Q000494:pharmacology; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology; D009553:Nimodipine; D010911:Pituitary Neoplasms / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*
D002121:Calcium Channel Blockers; D009539:Nicotinic Acids; D009553:Nimodipine; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D011388:Prolactin; D009543:Nifedipine