title: Calcium channel modulation by the dihydropyridine derivative Bay K 8644 in mammalian visceral smooth muscle cells.
abstract: 1. Modulation of Ca channels by the dihydropyridine Ca agonist Bay K 8644 in guinea-pig taenia coli smooth muscle cells was investigated using the patch clamp technique. 2. Single Ca channel activity was obtained from cell-attached patch recordings with the use of pipettes filled with 50 mM Ba. Bath application of the drug markedly increased the opening probability of Ca channels. 3. The effect was found to be due to an increase in the mean opening times of Ca channels. Due to this increase, the mean current reconstructed by averaging individual current trace responses was markedly increased in the presence of Bay K 8644.
mesh_terms: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003106:Colon / Q000187:drug effects / Q000378:metabolism; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects* / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects* / Q000378:metabolism
chemical_list: D007473:Ion Channels; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D002118:Calcium