Tocainide blocks Na currents by accumulation of inactivated Na channels.
The effect of tocainide on the voltage-dependent parameters of Na permeability was studied in voltage clamp experiments performed in single myelinated rat and frog nerve fibres. The main effect of tocainide was a potential- and frequency-dependent block of Na channels in both species. There was no shift to the voltage-dependent parameters of steady state Na activation (m infinity) or of the time constants of Na activation (tau m) and inactivation (tau h) along the potential axis.
Schwarz
J R
JR
Physiologisches Institut, Universitätskrankenhaus Eppendorf, Hamburg, F.R.G.
Grigat
G
G
D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects; D004553:Electric Conductivity / Q000187:drug effects; D004594:Electrophysiology; D008012:Lidocaine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009413:Nerve Fibers, Myelinated / Q000187:drug effects*; D011898:Ranidae; D051381:Rats; D011919:Rats, Inbred Strains; D015222:Sodium Channels / Q000187:drug effects* / Q000378:metabolism; D013045:Species Specificity; D016677:Tocainide
D015222:Sodium Channels; D016677:Tocainide; D008012:Lidocaine