Swiss RjOrl mice were pre-treated with ebselen (0-50 mg/kg) intraperitoneally (IP) prior to administration of ethanol (0-3.75 g/kg; IP). In another experiment, animals were pre-treated with ebselen (0 or 25 mg/kg; IP) before caffeine (15 mg/kg; IP), amphetamine (2 mg/kg; IP) or cocaine (10 mg/kg; IP) administration. Following these treatments, animals were placed in an open field to measure their locomotor activity. Additionally, we evaluated the effect of ebselen on the H2O2-mediated inactivation of brain catalase activity by 3-amino-1,2,4-triazole (AT).
Ebselen selectively prevented ethanol-induced locomotor stimulation without altering the baseline activity or the locomotor stimulating effects caused by caffeine, amphetamine and cocaine. Ebselen reduced the ability of AT to inhibit brain catalase activity.
Taken together, these data suggest that a decline in H2O2 levels might result in a reduction of the ethanol locomotor-stimulating effects, indicating a possible role for H2O2 in some of the psychopharmacological effects produced by ethanol.