RESUMO
BACKGROUND: Ethanol (EtOH), one of the most widely consumed substances of abuse, can induce brain damage and neurodegeneration. EtOH is centrally metabolized into acetaldehyde, which has been shown to be responsible for some of the neurophysiological and cellular effects of EtOH. Although some of the consequences of chronic EtOH administration on cell oxidative status have been described, the mechanisms by which acute EtOH administration affects the brain's cellular oxidative status and the role of acetaldehyde remain to be elucidated in detail. METHODS: Swiss CD-I mice were pretreated with the acetaldehyde-sequestering agent d-penicillamine (DP; 75 mg/kg, i.p.) or the antioxidant lipoic acid (LA; 50 mg/kg, i.p.) 30 minutes before EtOH (2.5 g/kg, i.p.) administration. Animals were sacrificed 30 minutes after EtOH injection. Glutathione peroxidase (GPx) mRNA levels; GPx and glutathione reductase (GR) enzymatic activities; reduced glutathione (GSH), glutathione disulfide (GSSG), glutamate, g-L-glutamyl-L-cysteine (Glut-Cys), and malondialdehyde (MDA) concentrations; and protein carbonyl group (CG) content were determined in whole-brain samples. RESULTS: Acute EtOH administration enhanced GPx activity and the GSH/GSSG ratio, while it decreased GR activity and GSSG concentration. Pretreatment with DP or LA only prevented GPx activity changes induced by EtOH. CONCLUSIONS: Altogether, these results show the capacity of a single dose of EtOH to unbalance cellular oxidative homeostasis.
