Rats, which were made chronically alcoholic in combination with L-N-o-nitro-arginine (L-NNA) treatment (5 mg/kg/day), a nitric oxide (NO) synthase inhibitor, showed a significant decrease in their alcohol preference and hypermotility during the withdrawal period by comparison with chronically alcoholic rats. However, no difference in the global liquid consumption between treated and untreated rats during the withdrawal stage was identified. In addition, the hypervascularization of the cortical area observed after chronic alcoholism was significantly decreased in the rats that had received L-NNA during the alcoholism procedure and was comparable to control rats. Thus, L-NNA alters both the behavioral preference for alcohol after alcoholism and the hypermotility during alcohol withdrawal, thus supporting the hypothesis of a direct implication of NO in alcohol abuse and its withdrawal. (C) 1997 Elsevier Science Inc.