Potent, hydroxyl radical-scavenging effect of apomorphine with iron and dopamine perfusion in rat striatum

Abstract

In dopaminergic neurons, free radicals are likely produced via dopamine metabolism by monoamine oxidase or via its auto-oxidation, a process facilitated by transition metals. In this study we examined the effect and possible mechanisms of apomorphine to reduce iron- and dopamine-induced 2,3-dihydroxybenzoic acid (2,3-DHBA) formation by microdialysis. We have shown that (1) FeSO 4·7H 2O reduced both the release of dopamine and the output of dihydroxyphenylacetic acid (DOPAC); (2) apomorphine may reduce FeSO 4·7H 2O-induced increases of 2,3-DHBA formation; (3) apomorphine has substantially reduced DOPAC output in early phase and blocked dopamine-induced increase of 2,3-DHBA levels. It is concluded that apomorphine is a potent hydroxyl radical scavenger in vivo, especially for the dopamine formation.