Chiba S, Watanabe H, Kobayashi M, Iwatsuki K
Jpn J Pharmacol. 1983 Feb;33(1):113-9. doi: 10.1254/jjp.33.113.
The right atrium of the dog was isolated and cross-perfused with arterial blood of another (donor) dog anesthetized with pentobarbital. When dobutamine, dopamine or isoproterenol was administered intravenously to the donor dog, the following changes were elicited in them: Dobutamine caused slight biphasic changes in heart rate. Dopamine induced biphasic changes in blood pressure and heart rate. Isoproterenol produced a decrease in blood pressure and a marked increase in heart rate. All these 3 catecholamines, however, induced positive chronotropic and inotropic effects in a similar fashion on the isolated atrium cross-perfused with blood of the donor dog. When injected into the cannulated sinus node artery of the isolated dog atrium, dobutamine, dopamine or isoproterenol induced monophasic positive chronotropic and inotropic effects in a dose-related manner, although the potency of each of the drugs was different. Dobutamine-induced effects were abolished by propranolol, but not modified by imipramine which suppressed significantly tyramine- and dopamine-induced effects. The difference in dobutamine-induced chronotropic effect between the whole animal and the isolated atrium may be due mainly to modification by extracardiac factors in the whole animal.
将狗的右心房分离出来，用戊巴比妥麻醉的另一只（供体）狗的动脉血进行交叉灌注。当向供体狗静脉注射多巴酚丁胺、多巴胺或异丙肾上腺素时，它们会出现以下变化：多巴酚丁胺引起心率轻微的双相变化。多巴胺引起血压和心率的双相变化。异丙肾上腺素导致血压下降和心率显著增加。然而，所有这三种儿茶酚胺对用供体狗血液交叉灌注的离体心房都以类似方式产生正性变时和变力作用。当将多巴酚丁胺、多巴胺或异丙肾上腺素注入离体狗心房的插管窦房结动脉时，它们以剂量相关的方式诱导单相正性变时和变力作用，尽管每种药物的效力不同。多巴酚丁胺诱导的效应被普萘洛尔消除，但未被丙咪嗪改变，丙咪嗪可显著抑制酪胺和多巴胺诱导的效应。在完整动物和离体心房中多巴酚丁胺诱导的变时效应的差异可能主要归因于完整动物中心外因素的调节。
