EFFECTS OF A HIGH FAT DIET ON OXYTOCIN RECEPTORS IN THE BRAINSTEM
Julie Ngo, Karen Bales.
University of California, Davis, Davis, CA.
While the hormone oxytocin (OT) is known for its role in childbirth, maternal bonding, and lactation, recently studies have suggested that OT can play a role in body weight regulation through several different circuits. Obesity and other metabolic disorders are an important chronic health issue, and OT could have an exciting potential use as a therapy. The relationship between OT and reduced feeding is thought to be mediated through OT receptors in brainstem areas linked to the regulation of meal size (e.g., nucleus of the solitary tract (NTS)). To further evaluate the relationship between OT and body weight, we used a diet-induced obesity model in adult male rats, which were given unlimited water and either a high-fat diet or rodent chow and received chronic infusions of either vehicle (saline) or OT (16 nmol/day) into the third ventricle. Our goal is to identify the extent to which alterations in OT receptor binding in the NTS may contribute to OT’s anorexigenic effects in diet-induced obese (DIO) rats. We expect higher binding in DIO animals than lean animals and lower binding in those treated with OT than in those treated with saline. The method used to assess binding will be receptor autoradiography.