Pertussis toxin-sensitive G-protein activation does not influence the response to Bay K 8644 in embryonic chick myocytes.
Pretreatment of embryonic chick cardiac myocytes with pertussis toxin (1-2.5 micrograms ml-1 for 22 h) abolished the negative chronotropic effects of carbachol but not the positive inotropic effects of Bay K 8644. Neither guanosine 5'-O-3-thiotriphosphate (GTP gamma S 500 microM intracellularly), nor pertussis toxin (0.5-1 microgram ml-1 for 22 h) modified the agonist effects of Bay K 8644 on calcium channel currents recorded under whole-cell voltage clamp. These findings indicate that pertussis-sensitive guanine nucleotide binding (G)-proteins does not modulate the effects of calcium channel activators in embryonic chick cardiac myocytes.
Anderson
A J
AJ
Syntex Research Centre, Edinburgh, Scotland.
Duncan
G P
GP
Spedding
M
M
Patmore
L
L
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology*; D000818:Animals; D015220:Calcium Channels / Q000187:drug effects*; D002478:Cells, Cultured; D002642:Chick Embryo; D006321:Heart / Q000187:drug effects*; D009206:Myocardium / Q000166:cytology; D009419:Nerve Tissue Proteins / Q000187:drug effects / Q000378:metabolism*; D037342:Pertussis Toxin; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D015220:Calcium Channels; C029152:G-substrate; D009419:Nerve Tissue Proteins; D010566:Virulence Factors, Bordetella; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D037342:Pertussis Toxin