Central QRFP‐26 in Female Rats: Effects on High Fat Intake, Meal Patterns and Hypothalamic Feeding Peptides

Abstract

Central administration of QRFP increases high fat diet (HFD), but not low fat diet (LFD) intake in male and cycling female rats. In males, QRFP's effects on HFD intake are regulated by neuropeptide Y (NPY) and the melanocortin system. The current experiments examined the effects of acute and sub‐chronic QRFP administration in female rats in the absence of estradiol. HFD intake, gene expression of hypothalamic NPY, agouti‐related peptide (AgRP) and pro‐opiomelanocortin (POMC) and meal patterns were assessed. In Experiment 1, HFD and LFD intake was measured following administration (icv) of QRFP in ovariectomized (OVX) rats. One week later, rats were administered QRFP and brains were harvested for the assessment of prepro‐NPY, AgRP and POMC mRNA in the mediobasal hypothalamus (MBH). In Experiment 2, following OVX, QRFP was administered centrally via an osmotic pump and food intake and meal patterns were continuously monitored using metabolic chambers for one week. At the end of one week, brains were harvested for the assessment of prepro‐NPY, AgRP and POMC mRNA in the MBH. Acute administration of QRFP increased HFD intake following OVX and increased the expression of AgRP mRNA in the MBH. Sub‐chronic administration of QRFP following OVX increased total HFD intake and HFD intake during the dark cycle and meal duration during the light cycle. An interaction between diet and QRFP was detected for prepro‐NPY expression in the MBH. These data support a role for QRFP as a mediator of HFD intake in the absence of estradiol and suggest that QRFP increases HFD intake by altering meal duration and hypothalamic expression of AgRP. LSUHSC to SDP; DK072476 PBRC