Homologous regulation of voltage-dependent calcium channels by 1,4-dihydropyridines.
Chronic treatment of PC 12 cells with the 1,4-dihydropyridine Ca2+ channel antagonist nifedipine [5 x 10-8M/5 days] and the activator S Bay K 8644 [5 x 10-7 M/5 days] resulted in up- and down-regulation of 1,4-dihydropyridine binding site density by 29 and 24%, respectively, without change in affinity. These changes in binding site density represent functional changes as indicated by the corresponding changes in K+ depolarization-induced 45Ca2+ uptake and in whole cell currents carried by Ba2+ ions. This homologous regulation of voltage-dependent Ca2+ channels [VDCC] by potent and specific ligands parallels that observed for other classes of membrane receptors.
Skattebøl
A
A
Department of Physiology, Baylor College of Medicine, Houston, Texas 77030.
Brown
A M
AM
Triggle
D J
DJ
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000818:Animals; D001464:Barium / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D002460:Cell Line; D004095:Dihydropyridines / Q000378:metabolism / Q000494:pharmacology*; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects*; D010673:Pheochromocytoma / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D011978:Receptors, Nicotinic / Q000187:drug effects
D015220:Calcium Channels; D004095:Dihydropyridines; D011978:Receptors, Nicotinic; D001464:Barium; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; C038806:1,4-dihydropyridine; D002118:Calcium