L-NOARG, an inhibitor of nitric oxide synthase, induces catalepsy in mice.

The objective of this study was to investigate possible motor effects of NG-nitro-L-arginine (L-NOARG), an inhibitor of nitric oxide synthase. Acute administration of L-NOARG (5-80 mg kg-1, i.p.) induced catalepsy in a dose-dependent manner in male albino-Swiss mice. The drug had an additive effect with haloperidol (0.125-0.5 mg kg-1, i.p.). The acute effect of L-NOARG (40 mg kg-1, i.p.) was attenuated by previous treatment with L-arginine (300 mg kg-1, i.p.). Sub-chronic treatment with L-NOARG (40 mg kg-1, i.p., twice a day for 4 days) was also able to attenuate the cataleptic effect of acute drug administration (40 mg kg-1, i.p.). These results show that acute systemic injections of L-NOARG induce significant motor effects.