Actions of the slow channel activator, Bay-K-8644, on the electrical activity of 3-day-old embryonic chick hearts.
In order to assess the effects of Bay-K-8644 on electrical activities of young embryonic chick hearts in which the rising phase of the action potential (AP) depends on tetrodotoxin-insensitive slow Na+ currents, slow AP were recorded in spontaneously beating 3-day-old embryonic chick hearts. Bay-K-8644(10(-6) mol/l) caused increases in the maximum rate of rise, amplitude, and duration of the slow AP; there was a slow increase in the spontaneous firing rate. Thus, Bay-K-8644 stimulates Na+ influx through TTX-insensitive slow channels.
Sada
H
H
Sada
S
S
Sperelakis
N
N
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002642:Chick Embryo; D006321:Heart / Q000187:drug effects* / Q000196:embryology; D007473:Ion Channels / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D008839:Microelectrodes; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology; D013997:Time Factors
D007473:Ion Channels; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D009543:Nifedipine