Functional characterisation of the neuropeptide Y receptor mediating feeding in the rat

Abstract

The present literature characterising the pharmacology of the hypothalamic receptor(s) responsible for mediating the hyperphagic effect of NPY is fragmented and far from comprehensive. Different groups of workers have studied NPY, its fragments and substituted analogues in the rat by administering these substances into the lateral or third brain ventricle or via direct administration into discrete hypothalamic nuclei [ 1-51. Much of this work has been performed using single doses of agonists and has utilised the porcine rather than the native series of neuropeptides.In the present work, we have performed a systematic analysis of the dose-feeding response relationship for hNPY and a number of its fragments and derivatives in order to define their relative potency and intrinsic activity for this action. These agents or vehicle were administered icv, during the light phase, to free-fed conscious male Sprague Dawley rats with an implanted lateral ventricular cannula. Food intake was measured hourly for 4 hours. Results were analysed by ANOVA using the 4 hour data.