Kelly M J
Methods Find Exp Clin Pharmacol. 1982 Aug-Sep;4(6):365-70.
In vitro experiments, using dopamine-induced relaxations of several pre-contracted rabbit blood vessels, confirmed the presence of renal dopamine receptors and suggested the existence of similar receptors in the portal vein and aorta. With jejunal muscle, however, dopamine's (spontaneous) relaxant effect was mediated by beta-adrenoceptors. The relaxant responses in the blood vessels were small, and quantitative information proved difficult to obtain. Therefore, a method of measuring alpha-adrenoceptor mediated contractile responses to dopamine was developed. Comparison of the respective antagonism of these responses produced by an alpha-adrenoceptor antagonist, phentolamine, and a dopamine receptor antagonist, haloperidol, showed differences between vascular and intestinal smooth muscle. The results suggest that this method is able to detect the presence of dopamine receptors in isolated tissues.
体外实验利用多巴胺对几只预先收缩的兔血管的舒张作用，证实了肾多巴胺受体的存在，并提示门静脉和主动脉中存在类似的受体。然而，对于空肠肌，多巴胺的（自发）舒张作用是由β - 肾上腺素能受体介导的。血管中的舒张反应较小，难以获得定量信息。因此，开发了一种测量α - 肾上腺素能受体介导的对多巴胺收缩反应的方法。比较α - 肾上腺素能受体拮抗剂酚妥拉明和多巴胺受体拮抗剂氟哌啶醇对这些反应的各自拮抗作用，显示出血管和平滑肌之间的差异。结果表明，该方法能够检测离体组织中多巴胺受体的存在。
