A Nitric Oxide Synthase Inhibitor Attenuates Neuropeptide Y—and Clonidine- Induced Feeding in the Neonatal Chick

Abstract

Bungo. T., Choi. Y.-H., Shimojo, M., Masuda. Y., Denbow, D.M. and Furuse, M. 2000. A nitric oxide synthase inhibitor attenuates neuropeptide Y- and clonidine- induced feeding in the neonatal chick. J. Appl. Anim. Res., 17: 257–264.

It is reported that inhibition of nitric oxide (NO) synthase (NOS) decreased food intake in mammalian and avian species. On the other hand, central administration of α₂-agonists stimulated, food, intake in both species. Similarly, neuropeptide Y (NPY) has the orcxigenic effect mediated by α₂ receptors. The present study was done to determine whether central injection of N^G-nitro-L-arginine methyl ester (L-NAME), a NOS inhibitor, in the neonatal chick modulates the increase in food intake induced by NPY- and clonidine (CLON, a specific α₂-agonist)-induced food intake. Both NPY (2.5 μg)- and CLON (50 ng)-induced food intake of neonatal chicks was significantly attenuated by co-administration with the higher doses of L-NAME (0, 0.2, 0.4 and 0.8 mg). Our results suggest that NO may interact with orexigenic systems in modulating food intake in the neonatal chick.

Key words:

• Nitric oxide
• neuropeptide Y
• clonidine
• feeding behavior
• chick