Central Neuropeptide W has Anorexigenic Effect in Rats

Neuropeptide W (NPW) is produced in neurons located in hypothalamus, brain stem, and antral G cells and its receptors are present in the hypothalamus, in particular in the paraventricular nucleus (PVN). There are two forms of the peptide, designated as neuropeptide W-23 (NPW23) and neuropeptide W-30 (NPW30). Neuropeptide W is an endogenous ligand for G protein-coupled receptor, GPR7- and GPR8-receptors (R), which in humans are expressed in the hypothalamus and probably involved in the regulation of energy homeostasis and neuroendocrine axes. We conducted this study to investigate the effects of NPW on feeding intake and energy expenditure in Wistar rats. Systemic (icv) injection of both forms of neuropeptide to ad-libitum feeding Wistar rats decreased dark feeding and fasting-induced feeding. One week of systemic treatment with NPW decreased feeding intake and weight gain during the treatment period. On the other hand, systemic treatment with anti-neuropeptide W antibody increased feeding intake. Moreover, systemic treatment with neuropeptide W raised body temperature and consequently thermogenesis. These results strongly suggest that neuropeptide W may plays an important central role in the feeding intake and energy balance regulation in mammals.