Regulation of feeding by galnon.

Galanin is a neuropeptide that has been implicated in multiple bioactivities, inter alia eating disorders. In this study, we have examined the effects of galnon, a novel low molecular weight galanin receptor ligand. Previous studies have shown that galnon acts as a systemically active, blood-brain barrier crossing agonist on galanin signaling both in vitro and in vivo, inhibiting pentylenetetrazole-induced seizures. Here, intracerebroventricular (10-20 microg) and intraperitoneal (1.5-5 mg/kg) administration of galnon induced a strong, dose-dependent reduction of food intake in rats and mice. This reduction in feeding occurred without reducing general activity and was shown to be attenuated by an intracerebroventricular administration of M35, a peptide galanin antagonist. These data demonstrate that galnon is a promising tool for studies of the involvement of galanin in feeding disorders and other behavioral processes.