title: Electrocautery-induced localized colonic injury elicits increased levels of pro-inflammatory cytokines in small bowel and decreases jejunal alanine absorption.
abstract: BACKGROUND
  Colitis is associated with functional abnormalities in proximal non-inflamed gut areas, but animal models to study small bowel dysfunction in colitis have limitations. This study aims to determine small intestinal alanine absorption and cytokine expression in a novel model of colonic ulceration induced by electro-cautery.
  
  
  METHODS
  A descending colon ulcer was induced in rats by a bipolar electro-cautery probe. Ulcer score was determined using Satoh's criteria. Jejunal alanine absorption was measured immediately and at different time intervals post ulcer induction. Levels of interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) protein and m-RNA were determined in mucosal scrapings obtained from the colon, duodenum, jejunum and ileum at various time intervals after colonic ulcer induction.
  
  
  RESULTS
  The mean ulcer score was 3 up to 48h, followed by healing by 96h post ulcer induction. Small bowel histology was normal throughout. Jejunal alanine absorption was reduced by 12-34% immediately and up to 72h after cautery and returned to normal at 96h. IL-1 and TNF-α mRNA increased significantly in the colon, duodenum, jejunum and ileum 3h post electro-cautery and returned to normal at 48h, while that of IL-6 increased significantly at 48h post ulcer induction. Similarly, IL-1, IL-6 and TNF-α protein levels increased in the duodenum, jejunum, ileum and colon up to 48h post ulcer induction.
  
  
  CONCLUSIONS
  Electrically induced localized colonic injury increased production of pro-inflammatory cytokines in non-inflamed segments of the small intestine and was associated with derangements of jejunal absorptive function.
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon. Electronic address: kb02@aub.edu.lb.
authors.forename: Kassem
authors.initials: K
authors.lastname: Barada
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon; Department of Anatomy, Cell Biology and Physiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
authors.forename: Fadi H
authors.initials: FH
authors.lastname: Mourad
authors.affiliation: Department of Anatomy, Cell Biology and Physiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
authors.forename: Bakiza
authors.initials: B
authors.lastname: Noutsi
authors.affiliation: Department of Anatomy, Cell Biology and Physiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
authors.forename: Nayef E
authors.initials: NE
authors.lastname: Saadé
mesh_terms: D000409:Alanine / Q000378:metabolism*; D000818:Animals; D003092:Colitis / Q000276:immunology / Q000503:physiopathology*; D003106:Colon / Q000276:immunology / Q000293:injuries; D016207:Cytokines / Q000378:metabolism*; D004195:Disease Models, Animal; D004386:Duodenum / Q000276:immunology / Q000378:metabolism; D004564:Electrocoagulation; D007082:Ileum / Q000276:immunology; D053583:Interleukin-1beta / Q000235:genetics / Q000276:immunology; D015850:Interleukin-6 / Q000235:genetics / Q000276:immunology; D007408:Intestinal Absorption; D007421:Intestine, Small / Q000276:immunology* / Q000378:metabolism; D007583:Jejunum / Q000276:immunology / Q000378:metabolism*; D008297:Male; D051381:Rats; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000276:immunology; D014456:Ulcer / Q000276:immunology / Q000503:physiopathology
chemical_list: D016207:Cytokines; D053583:Interleukin-1beta; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D000409:Alanine
keywords: Alanine absorption; Colitis; Cytokines; Electro-cautery