Inoue O, Kobayashi K, Hosoi R, Yamaguchi M, Gee A
Department of Medical Physics, School of Allied Health Sciences, Faculty of Medicine, Osaka University, Suita, Japan.
J Neural Transm (Vienna). 1999;106(11-12):1099-104. doi: 10.1007/s007020050226.
Competitive inhibition of 3H-raclopride (RAC) and 3H-N-methylspiperone (NMSP) binding against haloperidol, raclopride and NMSP was measured in the mouse striatum. 3H-RAC binding was more sensitive to competitive inhibition by all three compounds compared with 3H-NMSP. For example, 0.3 mg/kg of haloperidol resulted in 95% inhibition of 3H-RAC binding, however only 60% of inhibition of 3H-NMSP binding was found at the same dose of haloperidol. The cross-inhibition experiments using non-radioactive RAC or NMSP as competitors indicated different binding sites for 3H-RAC and 3H-NMSP in mouse striatum. Specifically, about 40% of 3H-NMSP binding was not displaced by treatment with a very high dose of raclopride (3 mg/kg). The time course of inhibition of the specific binding of 3H-RAC and 3H-NMSP were measured following i.p. injection of 0.5 mg/kg of haloperidol. No significant differences in the kinetics of haloperidol inhibition were observed between two radioligands.
在小鼠纹状体中测定了3H-雷氯必利（RAC）和3H-N-甲基螺哌隆（NMSP）与氟哌啶醇、雷氯必利和NMSP结合的竞争性抑制作用。与3H-NMSP相比，3H-RAC结合对这三种化合物的竞争性抑制更敏感。例如，0.3mg/kg的氟哌啶醇导致3H-RAC结合被抑制95%，然而在相同剂量的氟哌啶醇下，仅发现3H-NMSP结合被抑制60%。使用非放射性RAC或NMSP作为竞争剂的交叉抑制实验表明，在小鼠纹状体中3H-RAC和3H-NMSP具有不同的结合位点。具体而言，用非常高剂量的雷氯必利（3mg/kg）处理后，约40%的3H-NMSP结合未被取代。腹腔注射0.5mg/kg氟哌啶醇后，测定了3H-RAC和3H-NMSP特异性结合的抑制时间进程。两种放射性配体之间未观察到氟哌啶醇抑制动力学的显著差异。
