[Effect of trimecaine and its quaternary derivative G-103 on myocardial action potentials]

The conventional microelectrode technique was used to study the effects of trimecaine and its quaternary derivative G-103 on the action potential in the rat myocardium. G-103 suppressed the maximal rate of the action potential depolarization at lower concentrations than trimecaine although its effect developed slower: t 1/2 = 25 and 5 min, respectively. G-103 abolished the tonic component of trimecaine-induced blockade and failed to alter the rate-dependent component.