目的 对比分析多巴胺1(DA1)受体激动剂非 诺多泮（fenoldopam,FODA）对大鼠肺动脉和肠系膜动脉的影响。方法 采用cAMP含量放射免疫测定法测定 DAl受体激动剂FODA对肺动脉和肠系膜动脉cAMP的影响。结果 FODA可剂量依赖性 增加肠、肺动脉cAMP的生成量，然而，肠动脉cAMP的生成量显著高于肺动脉cAMP 的生成量。选择性多巴胺(DAl)受体阻断剂SCH-23390能够阻断FODA所引起的肺动脉和肠动脉cAMP生成量增加，多巴胺2(DA2)受体阻断剂domperidone则不影响FODA的作用。结论 兔肺动脉和肠动脉均存在有刺激腺苷酸环化酶（AC）活性的DAl受体。但肺动脉DAl受体 的 位点数明显少于肠动脉DAl受体位点数，从而提示肺动脉DAl受体的生理作用弱于肠动脉。%Objective To evaluate and compare the eff ects of DA1 receptor agonist, fenoldopam, on rabbit pulmonary and mesenteric a rteries.Methods Radioimmunoassay was used for determining the effects of fenoldopam on the cAMP generating system in rabbit mesenteric and pulmonary a rteries. Results The selective DA1-receptors agonist, fenoldopam, induce d a dose-related increase of cAMP formation in mesenteric and pulmonary arteries; h owe ver, the magnitude of increase in the mesenteric artery was remarkably greater t han that in the pulmonary artery. The selective DA1-receptors antagonist, SCH -233 90, blocked fenoldopam-induced cAMP production, while the selective DA2-rece pt ors antagonist, domperidone, was without effect on the increase of cAMP elicited by fenoldopam. Conclusion The presence of DA1-receptors is associated with stimulation of AC activity in both mesenteric and pulmonary arteries. Howe ver, there are much fewer receptor sites in the pulmonary artery than in mesente ric artery, suggesting less physiological importance of such receptors in the pu lmonary artery than in the mesenteric artery.
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