Pendleton R G, Finlay E, Sherman S
Naunyn Schmiedebergs Arch Pharmacol. 1975;289(2):171-8. doi: 10.1007/BF00501304.
We have found bulbocapnine to be an effective, apparently competitive inhibitor of dopamine depressor responses in the anesthetized, phenoxybenzamine-treated cat. The duration of action of the compound as a dopaminergic antagonist exceeded 3 hrs after an intravenous dose of 8 mg/kg. In the same preparation, however bulbocapnine did not at all inhibit the depressor responses to acetylcholine, histamine and isoproterenol, indicating a selectivity of action. Although administration of a high dose of propranolol (2 mg/kg, i.v.) did not alter the response of the alpha-receptor blocked cat to dopamine, the subsequent infusion of bulbocapnine remained effective. These results suggest that dopamine is acting as a blood pressure depressor agent via a unique receptor mechanism.
我们发现紫堇灵是一种有效的、明显具有竞争性的抑制剂，可抑制麻醉的、用酚苄明处理过的猫体内多巴胺降压反应。静脉注射8mg/kg剂量后，该化合物作为多巴胺能拮抗剂的作用持续时间超过3小时。然而，在相同的实验制剂中，紫堇灵完全不抑制对乙酰胆碱、组胺和异丙肾上腺素的降压反应，表明其作用具有选择性。尽管静脉注射高剂量的普萘洛尔（2mg/kg）不会改变α受体阻断猫对多巴胺的反应，但随后输注紫堇灵仍然有效。这些结果表明，多巴胺通过独特的受体机制作为一种血压降低剂发挥作用。
