Dihydropyridine sensitive calcium channels in a smooth muscle cell line.
The pharmacological properties of voltage sensitive calcium channels (VSCC) were examined in a rat aortic smooth muscle cell line (A10). The inorganic VSCC blockers Co2+ and Cd2+ blocked 45Ca2+ uptake into these cells in both 5 mM K+ and 50 mM K+ (depolarizing) conditions. The organic VSCC antagonists nitrendipine, nimodipine, D-600 and diltiazem also blocked 45Ca2+ uptake at low concentrations. The relative potencies of blockade were similar to those found in intact vascular smooth muscle. The VSCC "agonist" BAY K8644 enhanced 45Ca2+ uptake and this effect could be reversed by nitrendipine. These results indicate that A10 cells possess VSCC and that these VSCC behave similarly to those in authentic smooth muscle.
Kongsamut
S
S
Freedman
S B
SB
Miller
R J
RJ
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D000818:Animals; D002104:Cadmium / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D003035:Cobalt / Q000494:pharmacology; D004095:Dihydropyridines; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D009543:Nifedipine / Q000031:analogs & derivatives / Q000494:pharmacology; D009568:Nitrendipine; D011188:Potassium / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats
D004095:Dihydropyridines; D007473:Ion Channels; D011725:Pyridines; D002104:Cadmium; D003035:Cobalt; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; C038806:1,4-dihydropyridine; D009568:Nitrendipine; D009543:Nifedipine; D011188:Potassium; D002118:Calcium