title: Capsaicin abolishes lipoprivic but not glucoprivic feeding in rats.
abstract: To assess the contribution of visceral sensory neurons to feeding induced by blockade of glucose and fatty acid metabolism, adult rats were anesthetized and treated systemically with capsaicin, a toxin that destroys fine-diameter unmyelinated primary sensory neurons, including many visceral sensory neurons. Rats were maintained on a fat-supplemented diet throughout experimentation. For feeding tests, intake of this diet was measured hourly for 6 h after systemic blockade of fatty acid or glucose utilization with mercaptoacetate (MA) or 2-deoxy-D-glucose (2-DG), respectively, after simultaneous administration of MA and 2-DG and after saline injection. 2-DG stimulated a dose-related feeding response that was similar in magnitude in both capsaicin and vehicle-treated rats. MA also stimulated a dose-related feeding response in vehicle-treated rats. However, capsaicin-treated rats did not eat in response to MA. In addition, 2-DG and MA were additive in their stimulation of feeding in vehicle-treated controls, but capsaicin-treated rats ate the same amount after 2-DG plus MA as they did in response to 2-DG alone. Thus glucoprivation and lipoprivation activate anatomically and chemically distinct receptors for the metabolic control of feeding.
authors.affiliation: Department of Veterinary and Comparative Anatomy, Washington State University, Pullman 99164-6520.
authors.forename: S
authors.initials: S
authors.lastname: Ritter
authors.forename: J S
authors.initials: JS
authors.lastname: Taylor
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002211:Capsaicin / Q000494:pharmacology*; D003847:Deoxyglucose / Q000494:pharmacology; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D005247:Feeding Behavior / Q000187:drug effects*; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D013864:Thioglycolates / Q000494:pharmacology
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D013864:Thioglycolates; C017487:2-mercaptoacetate; D003847:Deoxyglucose; D002211:Capsaicin