Rozenshtraukh L V, Ruffy R, Elharrar V, Zipes D
Kardiologiia. 1979 May;19(5):63-72.
The electrophysiologic effects of ethmozin on canine myocardium were studied in anesthetized open-chest animals and in superfused Purkinje fibers. On selective injection into the sinus node artery and the posterior septal artery the drug caused no changes in the sinus node length and atrioventricular conduction, respectively. Intravenous infusion of 4 mg/kg ethmozin led to an increase of right and left ventricular diastolic excitability threshold and refractory period. Intravenous administration of 3--5 mg/kg ethmozin caused marked increase in conduction delay in which the ischemic zone of the left ventricle during acute coronary artery occlusion, which was associated with ventricular fibrillation in 50% of the dogs. In vitro, 1 x 10(-6) g/ml ethmozin shortened the Purkinje fibers' action potential duration whereas a dose of 1 x 10(-5) g/ml reduced the rate of phase 0 rise and slightly reduced the action potential amplitude. Ethmozin in a dose of 1 x 10(-7) g/ml increased transiently the isometric developed tension of false-tendon preparations. Higher concentrations caused marked depression of contractility. These observations suggest depression of the fast current by ethmozin. However, further studies are needed to elucidate its effect on action potential duration and false-tendor contractility.
在麻醉开胸动物和灌注的浦肯野纤维中研究了乙吗噻嗪对犬心肌的电生理作用。选择性注入窦房结动脉和后间隔动脉时，该药物分别未引起窦房结长度和房室传导的改变。静脉输注4mg/kg乙吗噻嗪导致右心室和左心室舒张期兴奋性阈值及不应期增加。静脉注射3 - 5mg/kg乙吗噻嗪导致传导延迟显著增加，其中急性冠状动脉闭塞时左心室缺血区的传导延迟与50%的犬发生心室颤动有关。在体外，1×10(-6)g/ml乙吗噻嗪缩短了浦肯野纤维动作电位持续时间，而1×10(-5)g/ml剂量降低了0期上升速率并轻微降低了动作电位幅度。1×10(-7)g/ml剂量的乙吗噻嗪可短暂增加假腱索标本的等长收缩张力。更高浓度则导致收缩力显著降低。这些观察结果提示乙吗噻嗪对快电流有抑制作用。然而，需要进一步研究以阐明其对动作电位持续时间和假腱索收缩力的影响。
