Inhibition of nitric oxide formation reduces voluntary ethanol consumption in the rat

Brain nitric oxide is involved in the mechanisms that regulate ingestive behaviour. To test whether this compound plays a role in alcohol preference, we studied the effects of different doses ofN^G-nitro-L-arginine (L-NO arg), an inhibitor of nitric oxide synthase (NOS), on voluntary consumption of ethanol and on blood alcohol levels produced by a single intraperitoneal dose of alcohol in the rat. L-NO arg produced a significant and dose-dependent reduction of ethanol intake (P<0.001) without influencing total fluid consumption or feeding behaviour. L-NO arg did not influence the kinetics of alcohol. Our data show that inhibition of nitric oxide formation accompanies reduction of ethanol intake and suggest a possible role for nitric oxide in ethanol self-administration.