Kobayashi M, Godin D, Nadeau R
Can J Physiol Pharmacol. 1983 Apr;61(4):308-14. doi: 10.1139/y83-047.
Direct injection of amiodarone (10-1000 micrograms) into the sinus node artery of the isolated blood-perfused dog atrium produced dose-dependent negative inotropic and chronotropic responses that were unaffected by atropine. Intraarterial amiodarone also had a negative inotropic action on isolated left ventricular muscle preparations electrically paced at 1.5 to 2.0 Hz. A continuous infusion of 100 micrograms/min of amiodarone significantly suppressed the positive chronotropic effect of norepinephrine whether expressed in percent change or in absolute values; its positive inotropic effect expressed in percent change was not suppressed but rather enhanced by amiodarone. Calcium chloride induced positive chronotropic and inotropic effects expressed in percent change were, respectively, slightly suppressed and enhanced by amiodarone. Intravenous injection of amiodarone (5 mg/kg) decreased the heart rate and blood pressure of the support dog and produced a negative inotropic response in the isolated left ventricular muscle preparation perfused with arterial blood from the support dog. These results suggest first, that amiodarone has direct negative inotropic and chronotropic effects that are not mediated by cholinergic mechanisms and second, that it has a depressive action on norepinephrine and calcium-induced positive chronotropic effects and an enhancing action on their positive inotropic effects.
将胺碘酮（10 - 1000微克）直接注入离体血液灌注犬心房的窦房结动脉，可产生剂量依赖性的负性肌力和负性变时反应，且不受阿托品影响。动脉内注射胺碘酮对以1.5至2.0赫兹频率进行电起搏的离体左心室肌制备物也有负性肌力作用。持续输注100微克/分钟的胺碘酮能显著抑制去甲肾上腺素的正性变时作用，无论以百分比变化还是绝对值表示；其以百分比变化表示的正性肌力作用并未被胺碘酮抑制，反而增强。氯化钙诱导的以百分比变化表示的正性变时和正性肌力作用分别被胺碘酮轻微抑制和增强。静脉注射胺碘酮（5毫克/千克）可降低供体犬的心率和血压，并对用供体犬动脉血灌注的离体左心室肌制备物产生负性肌力反应。这些结果表明，首先，胺碘酮具有直接的负性肌力和负性变时作用，且不是由胆碱能机制介导的；其次，它对去甲肾上腺素和钙诱导的正性变时作用有抑制作用，而对它们的正性肌力作用有增强作用。
