[In vitro electrophysiological effects of sodium dantrolene on isolated preparations of Purkinje fibers and ventricular myocardium of sheep].
Dantrolene sodium is a drug used in the treatment of spasticity and malignant hyperthermia. It is known to have a myorelaxant effect related to inhibition of the "release" of calcium by the sarcoplasmic reticulum of striated skeletal muscle. A direct cardiac effect which has only recently been suspected was demonstrated in vitro on isolated preparations of sheep Purkinje fibres and ventricular myocardium. Dantrolene caused a spectacular lengthening of the duration of the action potential of Purkinje fibres. This could be due either to an action on the slow calcium current or to stimulation of an ingoing sodium current sensitive to tetrodotoxin (TTX). This effect on the cardiac action potentials could explain the antiarrhythmic properties of dantrolene sodium during attacks of malignant hyperthermia.
Lascault
G
G
Waxman
M B
MB
Grosgogeat
Y
Y
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D003620:Dantrolene / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D006329:Heart Conduction System / Q000187:drug effects*; D006352:Heart Ventricles / Q000187:drug effects; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects; D008012:Lidocaine / Q000494:pharmacology; D008305:Malignant Hyperthermia / Q000188:drug therapy; D011690:Purkinje Fibers / Q000187:drug effects*; D012756:Sheep; D012964:Sodium / Q000502:physiology
D007473:Ion Channels; D001285:Atropine; D008012:Lidocaine; D012964:Sodium; D003620:Dantrolene
Effets électrophysiologiques in vitro du dantrolène sodium sur des préparations isolées de fibres de Purkinje et de myocarde ventriculaire de mouton.