BROMOCRIPTINE PROTECTS MICE AGAINST 6-HYDROXYDOPAMINE AND SCAVENGES HYDROXYL FREE-RADICALS IN-VITRO

Pretreatment with bromocriptine (5 mg/kg, i.p., 7 days) completely pro tected against the decrease in mouse striatal dopamine and its metabol ites induced by intraventricular injection of 6-hydroxydopamine after intraperitoneal administration of desipramine, but similar pretreatmen t with L-DOPA/carbidopa (75/7.5 mg/kg, i.p., 7 days) showed only parti al protective effect. Furthermore, in an in vitro system that generate d .OH from FeSO4-H2O2, bromocriptine dose-dependently reduced the numb er of. OH radicals. These findings indicate that bromocriptine has a n europrotective effect against neurotoxins such as 6-hydroxydopamine, p robably due, in part, to its hydroxyl radical scavenging activity and inhibiting effect on dopamine turnover rate. This suggests that early introduction of bromocriptine in the therapy of Parkinson's disease ma y be superior to treatment with L-DOPA alone.