PHARMACOLOGICAL STUDIES ON THE MYOCARDIAL EFFECTS OF O, S-DICARBETHOXYTHIAMINE (DCET)

Abstract

It was presumed in the previous report (1) that DCET potentiates the twitch tension and the incomplete tetanus of striated muscle by facilitating effects in the excitationcontraction coupling process. The effects of DCET on the striated muscle are similar to those of quinidine (2, 3), i.e., (i) d-tubocurarine-like blocking at neuro-muscular junction, (ii) stabilizing effects on the muscle membrane, (iii) potentiation of both the twitch tension and incomplete tetanus, (iv) depression of the complete tetanus tension in higher doses.
DCET also has antiveratrinic effects in the isolated diaphragm of rats and the isolated sartorius muscle of toads (1). Arora et al. (4) demonstrated that antiveratrinic responses are the common properties of many antiarrhythmic agents, including quinine analogues, ataxic agents, and antihistaminics.
So it is well anticipated that DCET has quinidine-like antiarrhythmic properties in the cardiac muscle. In this experiment the antiarrhythmic activities of DCET are tested and compared with those of quinidine, and some mechanisms of these antiarrhythmic activities of DCET are clarified in the isolated atrium of guinea-pigs and rabbits.