Protein kinase C mediated regulation of calcium channels in PC-12 pheochromocytoma cells.
Depolarization of PC-12 pheochromocytoma cells with K+ produces an immediate increase in catecholamine release. The stimulation of release is blocked by Co2+, removal of extracellular Ca2+ or by dihydropyridine drugs such as nitrendipine. Release is enhanced by other dihydropyridines such as BAY K8644. Release is accompanied by a voltage dependent uptake of 45Ca2+ which is also blocked by Co2+ or nitrendipine and enhanced by BAY K8644. The phorbol ester phorbol 12-myristate-13-acetate (TPA) in the range 10(-9)-10(-6) M produced little effect by itself but augmented the K+ evoked release of catecholamine. An analog of TPA which does not activate protein kinase C was ineffective. In contrast, TPA in the same concentration range blocked influx of 45Ca2+ induced by 70 mM K+ or 70 mM K+/BAY K8644. 45Ca2+ influx produced by A23187 was not blocked by TPA. The results suggest a system by which protein kinase C may regulate the output of transmitters from secretory cells.
Harris
K M
KM
Kongsamut
S
S
Miller
R J
RJ
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D000310:Adrenal Gland Neoplasms / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D009543:Nifedipine / Q000031:analogs & derivatives / Q000494:pharmacology; D009568:Nitrendipine; D009638:Norepinephrine / Q000378:metabolism; D010673:Pheochromocytoma / Q000378:metabolism*; D010703:Phorbol Esters / Q000494:pharmacology; D011493:Protein Kinase C / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D007473:Ion Channels; D010703:Phorbol Esters; C008876:phorbol-12,13-didecanoate; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D009568:Nitrendipine; D011493:Protein Kinase C; D009543:Nifedipine; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium; D009638:Norepinephrine