Zhu L, Zhao R R, Zhang W F
Department of Pharmacy, The First Affiliated Hospital, Henan Medical University, Zhengzhou 450052, China.
Sheng Li Xue Bao. 2000 Jun;52(3):247-51.
Effects of selective dopamine-1 (DA(1)) receptor agonist fenoldopam and dopamine-2 (DA(2)) receptor agonist propy1-butyl-dopamine (PBDA) on the cAMP generation system in renal, pulmonary, mesenteric and femoral arteries of rabbits were studied. The results are as follows. (1) Fenoldopam increased the cAMP production in a dose-dependent manner in pulmonary, renal and mesenteric arteries. This effect of fenoldopam was markedly blocked by specific DA(1) receptor antagonist SCH23390, but not at all by specific DA(2) receptor antagonist domperidone. (2) PBDA induced a dose-dependent decrease in cAMP content in femoral artery. However, the antagonist also moderately increased a dose-dependent cAMP production in mesenteric, pulmonary, and renal arteries. (3) Domperidone significantly decreased the inhibitory effect of PBDA on cAMP production in femoral artery, while it stimulated cAMP production in mesenteric artery but was of no effect on that in renal and pulmonary arteries. (4) SCH23390 had no effect on the inhibitory action of PBDA in decreasing cAMP content in femoral artery, while it markedly decreased the stimulatory action of PBDA on cAMP production in renal, pulmonary and mesenteric arteries. These findings suggest the presence of DA(1) receptors mediating the cAMP generation system in renal, pulmonary and mesenteric arteries, but only DA(2) receptors in femoral artery, and both DA1 and DA(2) receptors in mesenteric artery. PBDA inhibits the AC activity via stimulation of DA(2) receptors and increases the AC activity via stimulation of DA(1) receptors.
研究了选择性多巴胺-1（DA(1)）受体激动剂非诺多泮和多巴胺-2（DA(2)）受体激动剂丙基丁基多巴胺（PBDA）对兔肾动脉、肺动脉、肠系膜动脉和股动脉中环磷酸腺苷（cAMP）生成系统的影响。结果如下：（1）非诺多泮在肺动脉、肾动脉和肠系膜动脉中以剂量依赖性方式增加cAMP的产生。非诺多泮的这种作用被特异性DA(1)受体拮抗剂SCH23390显著阻断，但完全不受特异性DA(2)受体拮抗剂多潘立酮的影响。（2）PBDA导致股动脉中cAMP含量呈剂量依赖性降低。然而，该拮抗剂也适度增加了肠系膜动脉、肺动脉和肾动脉中剂量依赖性的cAMP产生。（3）多潘立酮显著降低了PBDA对股动脉中cAMP产生的抑制作用，同时它刺激了肠系膜动脉中cAMP的产生，但对肾动脉和肺动脉中cAMP的产生没有影响。（4）SCH23390对PBDA降低股动脉中cAMP含量的抑制作用没有影响，而它显著降低了PBDA对肾动脉、肺动脉和肠系膜动脉中cAMP产生的刺激作用。这些发现表明，在肾动脉、肺动脉和肠系膜动脉中存在介导cAMP生成系统的DA(1)受体，但在股动脉中仅存在DA(2)受体，而在肠系膜动脉中同时存在DA1和DA(2)受体。PBDA通过刺激DA(2)受体抑制腺苷酸环化酶（AC）活性，并通过刺激DA(1)受体增加AC活性。
