Morishita H, Furukawa T
Cardiovasc Res. 1980 Feb;14(2):103-7. doi: 10.1093/cvr/14.2.103.
Possible mechanisms involved in the action of dobutamine on blood vessels in isolated strips of dog artery were investigated and compared with noradrenaline, dopamine, and isoprenaline. In femoral strips, noradrenaline, dopamine, and dobutamine induced a dose-dependent contraction which was blocked by phenoxybenzamine. In strips previously contracted by KCl, after pretreatment with phenoxybenzamine, dobutamine induced a further contraction while isoprenaline produced a dose-dependent relaxation. However, dobutamine and isoprenaline elicited a dose-dependent relaxation in strips contracted by noradrenaline without phenoxybenzamine. This isoprenaline-induced relaxation was completely blocked by propranolol but the dobutamine-induced relaxation was in part attenuated by propranolol. In pulmonary strips, noradrenaline and dopamine elicited a dose-dependent contraction which was blocked by phenoxybenzamine, whereas dobutamine did not act on the strips. beta-Blockade by propranolol tended to potentiate the dobutamine-induced contraction of femoral strips, but did not affect the responses of pulmonary artery to dobutamine. In pulmonary arteries, the contractile responses to noradrenaline were antagonised by dobutamine. The results obtained here indicate that dobutamine exerts vascular actions by several different modes, such as an alpha-adrenergic agonistic and antagonistic action, an extremely weak beta 2 agonistic action, and a non-adrenergic contractile action.
研究了多巴酚丁胺对犬离体动脉条血管作用的可能机制，并与去甲肾上腺素、多巴胺和异丙肾上腺素进行了比较。在股动脉条中，去甲肾上腺素、多巴胺和多巴酚丁胺引起剂量依赖性收缩，该收缩可被酚苄明阻断。在用氯化钾预收缩的动脉条中，经酚苄明预处理后，多巴酚丁胺引起进一步收缩，而异丙肾上腺素产生剂量依赖性舒张。然而，在未经酚苄明处理的、由去甲肾上腺素收缩的动脉条中，多巴酚丁胺和异丙肾上腺素引起剂量依赖性舒张。异丙肾上腺素诱导的舒张被普萘洛尔完全阻断，但多巴酚丁胺诱导的舒张部分被普萘洛尔减弱。在肺动脉条中，去甲肾上腺素和多巴胺引起剂量依赖性收缩，该收缩可被酚苄明阻断，而多巴酚丁胺对动脉条无作用。普萘洛尔的β受体阻断作用倾向于增强多巴酚丁胺诱导的股动脉条收缩，但不影响肺动脉对多巴酚丁胺的反应。在肺动脉中，多巴酚丁胺可拮抗对去甲肾上腺素的收缩反应。此处获得的结果表明，多巴酚丁胺通过几种不同的方式发挥血管作用，如α肾上腺素能激动和拮抗作用、极弱的β2肾上腺素能激动作用以及非肾上腺素能收缩作用。
