POSSIBLE INVOLVEMENT OF NITRIC-OXIDE IN CHLORDIAZEPOXIDE-INDUCED FEEDING IN THE MOUSE

Two experiments investigated a possible role of nitric oxide (NO) in c hlordiazepoxide (CP)-induced feeding in nondeprived male ICR mice in i ndependent groups designs. Experiment 1 demonstrated a dose-related de crease in CP-induced solid food intake over a 60-min test period with increasing dose (10, 25, and 50 mg/kg SC) of the NO-synthase (NOS) inh ibitor, L-N-G-nitro arginine (L-NOARG), reaching statistical significa nce at 10 mg/kg L-NOARG when compared to vehicle control. Identical do ses of L-NOARG failed to significantly affect normal feeding in vehicl e treated mice. In Experiment 2, initial pretreatment with L-arginine (500 and 1000 mg/kg IF) partially or completely restored the feeding i nhibitory action of a challenge dose (25 mg/kg SC) of L-NOARG; D-argin ine (500 mg/kg IF) was ineffective, thus supporting a stereospecific a ction of arginine. Arginine isomers did not differentially affect inta ke in normal feeding animals. These results implicate involvement of N O in CP-induced hyperphagia; they are consistent with and extend resea rch linking NO and ingestive behaviors. Copyright (C) 1996 Elsevier Sc ience Inc.