Involvement of nitric oxide in the 5-HT1A autoreceptor-mediated hyperphagia in rats

Abstract

Effects of nitric oxide synthase(NOS) inhibitors on 8-hydroxy-2-di-n-(propylamino)tetralin (8-OH-DPAT)-induced hyperphagia which is mediated by the 5-HT autoreceptor were investigated. The non-selective NOS inhibitor NGnitro-L-arginine methyl ester (L-NAME) and neuronal NOS (nNOS) inhibitor 7-nitroindazole (7-NI) clearly suppressed increases in food intake by 8-OH-DPAT. Both hypophagic effects of L-NAME and 7-NI were reversed by the nitric oxide precursor, L-arginine. The findings suggest that nitric oxide formed in the brain is involved in 8-OH-DPAT-induced hyperphagia.