EFFECT OF (+ -)12-CHLOROSCOULERINE ON BRA IN DOPAMINE-RECEPTORS/

AIM: To assess potencies of tetrahydroprotoberberines (THPB) and hydro benzyltetrahydroisoquinolines (HBTI) on DA receptors. METHODS: The rec eptor binding assay with calf striatum to D-1 and D-2 receptors, and t he animal behavior tests were used. RESULTS: (+/-)12-Chloroscoulerine (CSL) was the most potent one among the THPB and HBTI. The affinities of CSL to D-1 and D-2 receptors were 13 and 51 nmol L(-1), respectivel y, in rats, CSL showed an antagonistic effect on the stereotypy and in duced catalepsy. In the 6-OHDA lesioned rats, however, CSL exerted the agonistic effect to DA receptors. CONCLUSION: CSL had dual actions to DA receptors and its effects were similar to that of (-)stepholidine.