Neuropeptide QRFP decreased food intake in the lateral hypothalamus

Abstract

Severe eating disorders, such as obesity, bulimia, and anorexia keep increasing to epidemic proportions worldwide. Understanding of neuropeptides’ role in complex hunger/satiety mechanisms may allow new prospectives for treatment and prevention. Pyroglutamylated arginine-phenylalanine-amide peptides (QRFPs) are thought to enhance feeding following the central administration. In our study, QRFP-26 was delivered into the lateral hypothalamic area (LHA) of male Wistar rats by direct microinjections, as QRFP-26 expressing neurons and binding sights are densely present in this neural structure. The consumption of liquid food was measured over a 60-minute period. Both doses (100 and 200 ng) significantly decreased food intake. Neuropeptide Y1 receptor antagonist BIBP3226 eliminated the anorexigenic effect caused by QRFP-26 administration. QRFP-26 did not affect general locomotion, behavioral patterns examined in the Open-Field Test, or anxiety. This study is the first to report the anorexigenic action of QRFP-26 in the hypothalamus, emphasizing steady locomotion and anxiety levels. We have shown that the effect can be linked to the NPY Y1 receptor mechanism. Our observations also suggest the contribution of NPY system to the central regulation of stress and anxiety reactions.