We have demonstrated that low-level Pb-exposure increasesethanol (ET) intake in a two-bottle free-choice paradigm, an effect that wepostulate, may be mediated in part by catalase (CAT), the enzyme responsiblefor brain ethanol oxidation. In the present study, we sought to investigate theeffects of CAT activation on voluntary ET consumption. Thirty-five day-oldanimals exposed to 220 ppm Pb during gestation and lactation were presentedwith increasing ET solutions (2-10%) and water, 2 h/day for 28 days. Afterstable 10% ET intake was achieved, the animals were injected with vehicle or aCAT activator: 3-nitropropionic acid, 3-NPA (10, 20, or 30 mg/kg s.c.) 90 minbefore the corresponding ET free-choice session (days 25-28). Immediately afterthe last session, all rats were sacrificed and brain regions harvested tomeasure brain CAT activity. Blood was also collected to determine CAT activity,Pb, and ET levels. A 35-day-old and a 70-day-old group that did not consumeethanol were included. We demonstrated that the pretreatment with 3NPA (20 mg/kg)comparably increased ET intake in both groups, with Pb-exposed animals stillshowing higher intake than controls. No changes in ET consumption were observedin response to 10 mg/kg 3NPA, while the 30 mg/kg dose was able to increaseintake selectively in control animals. However, these effects were notaccompanied by similar increases in blood or brain CAT activity. These resultspoint out the potential critical role of this enzyme in the behavioralproperties of ET, an effect that was not correlated with CAT activity.