Methamphetamine-induced neuronal damage: a possible role for free radicals.

The hypothesis that methamphetamine-induced neuronal damage is mediated by the production of free radicals was evaluated by pretreating rats with either antioxidants or a superoxide dismutase (SOD) inhibitor. It was found that methamphetamine (dose range 6.25-25.0 mg/kg) caused long-lasting depletions of dopamine and serotonin in the striatum and that pretreatment with the antioxidants, ascorbic acid (10-100 mg/kg), ethanol (1 g/kg), mannitol (2 g/kg), or vitamin E (2 g/kg), attenuated these depletions, whereas pretreatment with the superoxide dismutase inhibitor diethyldithiocarbamate (200-400 mg/kg) exacerbated the depletions. The alteration of this effect by four different antioxidants, as well as an inhibitor of superoxidase dismutase, indicated that oxygen-free radicals may have a role in the methamphetamine-induced neurotoxicity.