Van Loon G R, Sole M J
Metabolism. 1980 Nov;29(11 Suppl 1):1119-23. doi: 10.1016/0026-0495(80)90020-7.
Plasma dopamine is present in free form in a concentration approximately equivalent to that of epinephrine and about 25% that of norepinephrine. It originates in a variety of tissues including sympathetic nerves and adrenal, and the percentage originating from the various sources remains unknown. Events that are associated with increases in sympathetic activity such as stress, exercise, standing, or hypovolemia are associated with increases in plasma dopamine concentration, although the responses may be of considerably smaller magnitude than those for plasma norepinephrine and epinephrine. The functional importance of dopamine in the periphery and of changes in circulating dopamine remain only poorly defined. These include possible roles in neurotransmission in sympathetic ganglia, altering renal vascular bed, modulation of aldosterone secretion and sodium excretion, mediation of certain stress responses, and others yet to be revealed.
血浆多巴胺以游离形式存在，其浓度约与肾上腺素相当，约为去甲肾上腺素浓度的25%。它起源于包括交感神经和肾上腺在内的多种组织，而源自各种来源的百分比仍不清楚。与交感神经活动增加相关的事件，如压力、运动、站立或血容量不足，都与血浆多巴胺浓度增加有关，尽管其反应程度可能比血浆去甲肾上腺素和肾上腺素的反应小得多。多巴胺在周围组织中的功能重要性以及循环多巴胺的变化仍未明确界定。这些可能包括在交感神经节神经传递中的作用、改变肾血管床、调节醛固酮分泌和钠排泄、介导某些应激反应以及其他有待揭示的作用。
