Failure to detect 6-hydroxydopamine in rat striatum after the dopamine releasing drugs dexamphetamine, methylamphetamine and MPTP.

Large doses of dexamphetamine, methylamphetamine and MPTP failed to induce the formation of 6-hydroxydopamine (6-OHDA) in rat striatum. The potent dopamine (DA) releasing actions of these drugs and of the MPTP metabolite MPP+ were shown by intracerebral dialysis of DA in conscious rats but 6-OHDA was not detectable in the perfusates. Neurotoxic effects of these DA releasing drugs are therefore probably not due, as previously suggested, to 6-OHDA formation and its subsequent uptake into nerve terminals.