Anorectic activity of NG-nitro-L-arginine, an inhibitor of brain nitric oxide synthase, in obese Zucker rats.

We investigated the effects of NG-nitro-L-arginine (L-NO Arg) administration (12.5, 25 and 50 mg/kg i.p.) on food consumption and body weight of male obese Zucker rats (fa/fa) and in their lean age-matched controls (FA/?; FA/FA), both groups aged 14 weeks. Acute or repeated administration of L-NO Arg reduced food intake and body weight in both obese and lean rats. However the lean rats showed tolerance to the L-NO Arg effects after 5 days of treatment. L-NO Arg anorexia was suppressed by pretreatment with metergoline. These results suggest that L-NO Arg may represent a new anorectic drug.