Pinnock R D
Br J Pharmacol. 1984 Apr;81(4):631-5. doi: 10.1111/j.1476-5381.1984.tb16128.x.
The activity of neurones in the zona compacta of the rat substantia nigra was recorded extracellularly in vitro. Dopamine produced a dose-dependent depression of firing, threshold doses being in the 3 microM range. The inhibitory effects of dopamine were antagonized by (-)-sulpiride (pA2 7.5), haloperidol (pA2 8.4) and cis-flupenthixol (pA2 6.9). The actions of gamma-aminobutyric acid (GABA) were not affected by these compounds. The gradients of Schild plots of data for (-)-sulpiride were less than unity while those for haloperidol and cis-flupenthixol were greater than unity, which suggests that the antagonism was not competitive. This is discussed with regard to the use of a bioassay system in the analysis of the effects of antagonists. Haloperidol and (-)-sulpiride were found to have similar potencies, as dopamine receptor antagonists, to those predicted from biochemical and clinical efficacy studies, but cis-flupenthixol was less potent than expected.
在体外对大鼠黑质致密部神经元的活动进行了细胞外记录。多巴胺产生了剂量依赖性的放电抑制，阈剂量在3微摩尔范围内。多巴胺的抑制作用被（-）-舒必利（pA2 7.5）、氟哌啶醇（pA2 8.4）和顺式氟奋乃静（pA2 6.9）拮抗。γ-氨基丁酸（GABA）的作用不受这些化合物的影响。（-）-舒必利数据的Schild图斜率小于1，而氟哌啶醇和顺式氟奋乃静的斜率大于1，这表明拮抗作用不是竞争性的。结合生物测定系统在拮抗剂作用分析中的应用对此进行了讨论。发现氟哌啶醇和（-）-舒必利作为多巴胺受体拮抗剂，其效力与生化和临床疗效研究预测的相似，但顺式氟奋乃静的效力低于预期。
