Role of nitric oxide in experimental models of psychosis in rats.
The aim of our study was to investigate the effects of the NO precursor L-arginine and the nitric oxide synthase inhibitor N omega-nitro-L-arginine (L-NORAG) on amphetamine-induced stereotypy, haloperidol-induced catalepsy and conditioned avoidance response (CAR) in rats. Amphetamine (3 mg/kg i.p.) was used for the induction of stereotypy, while for the induction of catalepsy and CAR, haloperidol (2 mg/kg i.p.) was used. This study was divided into 2 parts--acute administration of L-arginine (150 mg/kg i.p.) and L-NOARG (50 mg/kg i.p.) and chronic administration of L-arginine (150 mg/kg/day i.p.) and L-NOARG (50 mg/kglday i.p.) for 5 days. We found that L-arginine inhibited amphetamine-induced stereotypy and haloperidol-induced catalepsy, but intensified CAR. On the other hand, L-NOARG intensified stereotypy and catalepsy but inhibited CAR. Also, there was no significant difference between the scores of acute and chronic administration of L-arginine and L-NOARG. It is concluded from our study that nitric oxide produces conflicting results on various models of psychosis. L-arginine might be useful as an antipsychotic without causing extrapyramidal symptoms.
Gupta
M
M
Department of Pharmacology, Postgraduate Institute of Medical Education & Research, Chandigarh, India.
Balakrishnan
S
S
Pandhi
P
P
D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects; D002375:Catalepsy / Q000139:chemically induced; D005260:Female; D008297:Male; D009569:Nitric Oxide / Q000502:physiology*; D019335:Nitroarginine / Q000494:pharmacology; D010622:Phencyclidine / Q000494:pharmacology; D011618:Psychotic Disorders / Q000188:drug therapy / Q000209:etiology*; D051381:Rats; D013239:Stereotyped Behavior / Q000187:drug effects
D019335:Nitroarginine; D009569:Nitric Oxide; D001120:Arginine; D010622:Phencyclidine