Exposure of mice to tobacco smoke attenuates the toxic effect of methamphetamine on dopamine systems

Methamphetamine treatment of mice rapidly and severely depleted levels of d opamine and its metabolites. homovanillic acid (HVA) and dihydroxyphenylace tic acid (DOPAC) in the caudate nucleus. Exposure of mice to cigarette smok e by means of nose-only breathing apparatus for 20 min twice daily over 3 d ays prior to drug treatment significantly attenuated the neurotoxicity of m ethamphetamine as judged by a lesser depletion of dopamine. DOPAC and HVA. The lesser effect of methamphetamine upon content of serotonin level was un altered by prior inhalation of smoke. Results suggest a specific protective effect of inhaled tobacco smoke upon the effects of methamphetamine upon d opaminergic circuitry. (C) 2000 Elsevier Science Ireland Ltd. All rights re served.