Selenium deficiency potentiates methamphetamine-induced nigral neuronal loss; comparison with MPTP model

The present study was designed to understand the role of an antioxidant, selenium (Se) on methamphetamine (MA)-induced dopaminergic cell damage in the substantia nigra (SN). Male C57BL/6J mice were fed either selenium-deficient (<0.01 ppm Se) or selenium-replete (0.2 ppm Se) diet for 90 days. Se-deficiency potentiates MA-induced reductions of tyrosine hydroxylase-like immunoreactivity (TH-IR), dopamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanilic acid (HVA) in the SN. These dopaminergic toxicities were comparable to that induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). By contrast, Se-repletion significantly blocked dopaminergic toxicity after MA treatments. These results suggest that Se-deficient MA-treated mouse is a relevant model of Parkinsonism, and that optimal level of Se plays a crucial role in preventing nigral dopaminergic toxicity induced by MA. However, different mechanisms in the thermoregulation mediated by MA or MPTP remain to be further determined. (C) 2000 Elsevier Science B.V. All rights reserved.