title: Sleeve gastrectomy reduces xanthine oxidase and uric acid in a rat model of morbid obesity.
abstract: BACKGROUND
  Serum uric acid (sUA) plays a major role in the development of morbidities associated with obesity, especially cardiovascular diseases. Within the purine pathway, xanthine oxidase (XOD) represents the key enzyme. The aim of this study was to investigate the dynamics of sUA and XOD following sleeve gastrectomy (SG) in a rat model of high-fat-diet (HFD) induced obesity.
  
  
  METHODS
  Over a period of 11 weeks, 30 rats received a HFD, and 10 rats received a low fat diet (LFD). Thereafter, 10 randomly selected HFD rats and 10 LFD rats were sacrificed. The remaining 20 HFD rats were randomly assigned to either SG or sham operation (SH) and studied 14 days postoperatively.
  
  
  METHODS
  The white adipose tissues (WAT) from visceral (intestinal and retroperitoneal) and inguinal (subcutaneous) depots were collected. sUA and urine UA (uUA) were measured by high performance liquid chromatography-mass spectrometry (HPLC-MS/MS). Abundance and activity of XOD was investigated in the liver, colon, adipose tissue, and skeletal muscle by enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  HFD led to significant weight gain, elevated sUA levels, increased WAT and increase of XOD activity. Fourteen days postoperatively, SG rats showed a significant decrease of weight and adipose tissue, improved glucose metabolism, and changes of gut hormones. The sUA and uUA levels were significantly decreased following SG. Furthermore, XOD activity was significantly down-regulated in WAT.
  
  
  CONCLUSIONS
  HFD induces elevated sUA levels by gain of WAT and increase of XOD activity. Following SG, the reduction of WAT as the major source of XOD and the lowering of XOD activity are the basis for the decrease of sUA.
authors.affiliation: Department of Cardiac Surgery, University of Leipzig, Heart Center, Leipzig, Germany; Department of Health Sciences / Public Health, University of Dresden, Dresden, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Oberbach
authors.affiliation: Department of Urology, University of Leipzig, Leipzig, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Neuhaus
authors.affiliation: Integrated Research and Treatment Center (IFB) Adiposity Diseases, University of Leipzig, Leipzig, Germany.
authors.forename: Nadine
authors.initials: N
authors.lastname: Schlichting
authors.affiliation: Department of Health Sciences / Public Health, University of Dresden, Dresden, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Kugler
authors.affiliation: Department of Metabolomics, Helmholtz Centre for Environmental Research, Leipzig, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Baumann
authors.affiliation: Department of Pediatrics and Adolescent Surgery, Medical University of Graz, Graz, Austria. Electronic address: Holger.till@medunigraz.at.
authors.forename: Holger
authors.initials: H
authors.lastname: Till
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D059305:Diet, High-Fat; D004195:Disease Models, Animal; D005743:Gastrectomy; D005768:Gastrointestinal Hormones / Q000378:metabolism; D008297:Male; D009767:Obesity, Morbid / Q000209:etiology / Q000378:metabolism* / Q000601:surgery*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014527:Uric Acid / Q000378:metabolism*; D014969:Xanthine Oxidase / Q000378:metabolism*
chemical_list: D001786:Blood Glucose; D005768:Gastrointestinal Hormones; D014527:Uric Acid; D014969:Xanthine Oxidase
keywords: High fat diet; Obesity; Rat; Sleeve gastrectomy; Uric acid; Xanthine oxidase