Albillos A, Abad F, García A G
Departamento de Farmacología, Facultad de Medicina, Universidad Autónoma de Madrid, Spain.
Biochem Biophys Res Commun. 1992 Mar 31;183(3):1019-24. doi: 10.1016/s0006-291x(05)80292-x.
In the study reported here we have reached two conclusions. First, the cat adrenal medulla chromaffin cell possesses a dopamine D1 receptor that seems to be coupled to an adenylyl cyclase. Second, this receptor regulates the muscarinic-mediated catecholamine release response through a negative feed-back loop which uses cyclic AMP as a second messenger. These conclusions are supported by the following findings: (i) SKF38393 (a selective D1 receptor agonist), but not quinpirole (a selective D2 agonist), inhibits the methacholine-mediated catecholamine release responses in a concentration-dependent manner (IC50 of around 1-2 microM). (ii) SCH23390 (a selective D1 antagonist), but not sulpiride (a selective D2 antagonist), reversed by 70% the inhibitory effects of SKF38393. (iii) Dibutyril cyclic AMP (500 microM) inhibited by 80% the secretory effects of methacholine.
在本文报道的研究中，我们得出了两个结论。第一，猫肾上腺髓质嗜铬细胞拥有一种多巴胺D1受体，该受体似乎与腺苷酸环化酶偶联。第二，此受体通过一个以环磷酸腺苷作为第二信使的负反馈环调节毒蕈碱介导的儿茶酚胺释放反应。这些结论得到以下研究结果的支持：(i) SKF38393（一种选择性D1受体激动剂）而非喹吡罗（一种选择性D2激动剂）以浓度依赖的方式抑制乙酰甲胆碱介导的儿茶酚胺释放反应（IC50约为1 - 2微摩尔）。(ii) SCH23390（一种选择性D1拮抗剂）而非舒必利（一种选择性D2拮抗剂）使SKF38393的抑制作用逆转了70%。(iii) 二丁酰环磷酸腺苷（500微摩尔）使乙酰甲胆碱的分泌作用抑制了80%。
