Calcium entry activators: distinct sites of dihydropyridine and aminopyridine action.
The dihydropyridine compound BAY K 8644, a putative calcium entry activator, inhibits binding of the dihydropyridine calcium entry blocker, [3H]nitrendipine, to rat skeletal muscle membranes. In contrast, aminopyridine compounds also believed to stimulate calcium flux do not interact with [3H]nitrendipine binding sites in skeletal muscle or brain. These findings suggest that calcium entry activators, like calcium entry blockers, affect voltage-dependent calcium channels by diverse mechanisms.
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D000631:Aminopyridines / Q000494:pharmacology*; D000818:Animals; D001921:Brain / Q000187:drug effects; D015220:Calcium Channels; D006863:Hydrogen-Ion Concentration; D007473:Ion Channels / Q000187:drug effects*; D008297:Male; D009132:Muscles / Q000187:drug effects; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011978:Receptors, Nicotinic / Q000187:drug effects*
D000631:Aminopyridines; D015220:Calcium Channels; D007473:Ion Channels; D011725:Pyridines; D011978:Receptors, Nicotinic; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D009543:Nifedipine