title: Obese rats exhibit high levels of fat necrosis and isoprostanes in taurocholate-induced acute pancreatitis.
abstract: BACKGROUND
  Obesity is a prognostic factor for severity in acute pancreatitis in humans. Our aim was to assess the role of oxidative stress and abdominal fat in the increased severity of acute pancreatitis in obese rats.
  
  
  METHODS
  Taurocholate-induced acute pancreatitis was performed in lean and obese Zucker rats. Levels of reduced glutathione, oxidized glutathione, L-cysteine, cystine, and S-adenosylmethionine were measured in pancreas as well as the activities of serine/threonine protein phosphatases PP1 and PP2A and tyrosin phosphatases. Isoprostane, malondialdehyde, triglyceride, and free fatty acid levels and lipase activity were measured in plasma and ascites. Lipase activity was measured in white adipose tissue with and without necrosis and confirmed by western blotting.
  
  
  RESULTS
  Under basal conditions obese rats exhibited lower reduced glutathione levels in pancreas and higher triglyceride and free fatty acid levels in plasma than lean rats. S-adenosyl methionine levels were markedly increased in pancreas of obese rats. Acute pancreatitis in obese rats led to glutathione oxidation and lower reduced glutathione levels in pancreas together with decreased activities of redox-sensitive phosphatases PP1, and PP2A. S-adenosyl methionine levels decreased but cystine levels increased markedly in pancreas upon pancreatitis. Acute pancreatitis triggered an increase in isoprostane levels in plasma and ascites in obese rats. Free fatty acid levels were extremely high in pancreatitis-associated ascitic fluid from obese rats and lipase was bound with great affinity to white adipose tissue, especially to areas of necrosis.
  
  
  CONCLUSIONS
  Our results show that oxidative stress occurs locally and systemically in obese rats with pancreatitis favouring inactivation of protein phosphatases in pancreas, which would promote up-regulation of pro-inflammatory cytokines, and the increase of isoprostanes which might cause powerful pulmonary and renal vasoconstriction. Future studies are needed to confirm the translational relevance of the present findings obtained in a rat model of taurocholate-induced pancreatic damage and necrosis.
authors.affiliation: Department of Physiology, School of Pharmacy, University of Valencia, Burjasot, Valencia, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Pereda
authors.forename: Salvador
authors.initials: S
authors.lastname: Pérez
authors.forename: Javier
authors.initials: J
authors.lastname: Escobar
authors.forename: Alessandro
authors.initials: A
authors.lastname: Arduini
authors.forename: Miguel
authors.initials: M
authors.lastname: Asensi
authors.forename: Gaetano
authors.initials: G
authors.lastname: Serviddio
authors.forename: Luis
authors.initials: L
authors.lastname: Sabater
authors.forename: Luis
authors.initials: L
authors.lastname: Aparisi
authors.forename: Juan
authors.initials: J
authors.lastname: Sastre
mesh_terms: D000818:Animals; D015153:Blotting, Western; D005978:Glutathione / Q000378:metabolism; D028421:Isoprostanes / Q000378:metabolism*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009765:Obesity / Q000378:metabolism* / Q000503:physiopathology; D018384:Oxidative Stress; D010179:Pancreas / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D019283:Pancreatitis, Acute Necrotizing / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology*; D051381:Rats; D011924:Rats, Zucker; D013656:Taurocholic Acid / Q000633:toxicity*; D014280:Triglycerides / Q000378:metabolism
chemical_list: D028421:Isoprostanes; D014280:Triglycerides; D008315:Malondialdehyde; D013656:Taurocholic Acid; D005978:Glutathione