title: Alterations of NADPH oxidase activity in rat pancreatic islets induced by a high-fat diet.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effect of a high-fat diet (HFD) on nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity in rat pancreatic islets. We investigated if changes in NADPH oxidase are connected to beta cell dysfunction reported in obese animals.
  
  
  METHODS
  Male Wistar rats were fed a HFD or control diet for 3 months. DNA fragmentation, insulin secretion, and [U-C]glucose oxidation were examined in isolated pancreatic islets. The oxidative stress markers nitrotyrosine and 4-hydroxy-2-nonenal were assessed by immunohistochemistry. The protein content of gp91 and p47 was evaluated by Western blotting. Production of reactive oxygen species (ROS) was determined by a fluorescence assay using hydroethidine.
  
  
  RESULTS
  Occurrence of DNA fragmentation was reduced in pancreatic islets from HFD rats. There were no differences in oxidative stress markers between the groups. Glucose oxidation and insulin secretion were elevated due to high glucose in pancreatic islets from HFD rats. Protein concentrations of p47 and gp91 subunits were reduced and ROS production was diminished in pancreatic islets from HFD rats.
  
  
  CONCLUSIONS
  The diminished content of NADPH oxidase subunits and ROS concentrations may be associated with increased glucose oxidation and insulin secretion in an attempt to compensate for the peripheral insulin resistance elicited by the HFD.
authors.affiliation: Department of Physiology and Biophysics, University of São Paulo, São Paulo, Brazil. mairamrv@icb.usp.br
authors.forename: Maíra Mello Rezende
authors.initials: MM
authors.lastname: Valle
authors.forename: Maria Fernanda Rodrigues
authors.initials: MF
authors.lastname: Graciano
authors.forename: Eduardo Rebelato
authors.initials: ER
authors.lastname: Lopes de Oliveira
authors.forename: João Paulo Gabriel
authors.initials: JP
authors.lastname: Camporez
authors.forename: Eliana Hiromi
authors.initials: EH
authors.lastname: Akamine
authors.forename: Carla Roberta de Oliveira
authors.initials: CR
authors.lastname: Carvalho
authors.forename: Rui
authors.initials: R
authors.lastname: Curi
authors.forename: Angelo Rafael
authors.initials: AR
authors.lastname: Carpinelli
mesh_terms: D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004041:Dietary Fats / Q000008:administration & dosage*; D005941:Glucokinase / Q000235:genetics; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000201:enzymology* / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D011384:Proinsulin / Q000235:genetics; D021122:Protein Subunits; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
chemical_list: D017931:DNA Primers; D004041:Dietary Fats; D007328:Insulin; D008562:Membrane Glycoproteins; D010750:Phosphoproteins; D021122:Protein Subunits; D012333:RNA, Messenger; C079789:neutrophil cytosol factor 67K; D011384:Proinsulin; C500593:Cybb protein, rat; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D005941:Glucokinase