[Effect of (+/-)12-chloroscoulerine on brain dopamine receptors].

AIM: To assess potencies of tetrahydroprotoberberines (THPB) and hydrobenzyltetrahydroisoquinolines (HBTI) on DA receptors.

METHODS

The receptor binding assay with calf striatum to D1 and D2 receptors, and the animal behavior tests were used.

RESULTS

(+/-) 12-Chloroscoulerine (CSL) was the most potent one among the THPB and HBTI. The affinities of CSL to D1 and D2 receptors were 13 and 51 nmol.L-1, respectively. In rats, CSL showed an antagonistic effect on the stereotypy and induced 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.