title: Sickness behavior is accentuated in rats with metabolic disorders induced by a fructose diet.
abstract: This study investigated behavioral responses to an immune challenge among animals with fructose-induced metabolic disorders. Adult male Wistar rats were provided either water or a fructose solution (10%) for 5 weeks. Sickness behaviors were assessed 2h following the injection of either a lipopolysaccharide (LPS) or vehicle. The rats were subjected to an open field test, a social interaction test, a food intake test and a fever evaluation. Cytokine expression was assessed in both adipose tissue and hypothalamus samples. The neural response was assessed in the forebrain immunohistochemistry for c-Fos. Compared with the control group, the fructose diet induced dyslipidemia and significantly higher plasma total cholesterol, HDL-cholesterol, triglyceride, and glucose levels as well as both epididymal and retroperitoneal adiposity. Furthermore, in response to LPS (1 mg/kg), the rats subjected to a fructose diet exhibited exacerbated sickness behaviors and accentuated febrile responses. LPS induced Fos protein expression in several areas of the brains of the control rats; however, higher numbers of Fos-positive cells were observed in the brains of the rats that were fed a fructose diet. Moreover, larger increases in cytokine expression were observed in both the hypothalamus and the adipose tissue of the obese rats compared with the control rats in response to LPS. In this study, fructose diets played an important role in both the induction of metabolic disorders and the modulation of sickness behaviors in response to an immunological challenge, most likely through the induction of cytokines in the hypothalamus.
authors.affiliation: Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis), Brazil.
authors.forename: Lidiane
authors.initials: L
authors.lastname: Orlandi
authors.affiliation: Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis), Brazil.
authors.forename: Wesley F
authors.initials: WF
authors.lastname: Fonseca
authors.affiliation: Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis), Brazil.
authors.forename: Silvia
authors.initials: S
authors.lastname: Enes-Marques
authors.affiliation: Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis), Brazil; Instituto de Ciências Biomédicas, Universidade Federal de Alfenas-MG, 37130-000 Alfenas, Brazil.
authors.forename: Valdemar A
authors.initials: VA
authors.lastname: Paffaro
authors.affiliation: Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis), Brazil.
authors.forename: Fabiana C
authors.initials: FC
authors.lastname: Vilela
authors.affiliation: Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis), Brazil; Instituto de Ciências Biomédicas, Universidade Federal de Alfenas-MG, 37130-000 Alfenas, Brazil. Electronic address: agiustipaiva@gmail.com.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Giusti-Paiva
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D004435:Eating / Q000187:drug effects; D005106:Exploratory Behavior / Q000187:drug effects; D005632:Fructose / Q000633:toxicity*; D005786:Gene Expression Regulation / Q000187:drug effects; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D055809:Illness Behavior / Q000502:physiology*; D007398:Interpersonal Relations; D008070:Lipopolysaccharides / Q000633:toxicity; D008297:Male; D008659:Metabolic Diseases / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism; D013549:Sweetening Agents / Q000633:toxicity*; D013997:Time Factors
chemical_list: D016207:Cytokines; D008070:Lipopolysaccharides; D016760:Proto-Oncogene Proteins c-fos; D012269:Ribosomal Proteins; D013549:Sweetening Agents; C050482:Rpl19 protein, rat; D005632:Fructose
keywords: Anorexia; Fever; Hypothalamus; Obesity; Social interaction