HEPATIC VAGOTOMY EFFECTS ON METABOLIC CHALLENGES DURING PARENTERAL-NUTRITION IN RATS

During parenteral nutrition (PN) glucoprivic-induced feeding appeared to be neutralized by the oxidation of infused fatty acids. With the us e of a latin-square design, the feeding response to a-deoxy-D-glucose (2-DG) and/or 2-mercaptoacetate (MA) was evaluated in male Sprague-Daw ley rats with hepatic branch vagotomy (HV) or sham operations (SO). Ra ts received continuous infusions of 0.9% saline or PN providing 100% o f daily caloric needs (PN-100) for four consecutive days. During PN-10 0, food intake was stimulated by 2-DG in HV rats and when fatty acid o xidation was simultaneously inhibited by MA. 2-DG-induced hyperglycemi a was apparent under all conditions. Lipoprivic-induced feeding and in creased plasma free fatty acid concentrations were absent in HV rats, whether MA was administered alone or with 2-DG. The feeding response t o glucoprivic challenges is influenced by the relative availability of alternate energy sources. The lack of feeding response to 2-DG during PN-100 is mediated by vagal input of hepatic fatty acid oxidation sta tus.