title: [Characterization of the antiinflammatory properties of methane inhalation during ischaemia-reperfusion].
abstract: BACKGROUND
  Gastrointestinal methane generation has been demonstrated in various conditions, but it is not known whether it has any impact on the mammalian physiology or pathophysiology. Our aim was to characterize the effects of exogenous methane on the process of inflammatory events induced by reoxygenation in a canine model of ischemia-reperfusion.
  
  
  METHODS
  Sodium pentobarbital-anesthetized inbred beagle dogs (n = 18) were randomly assigned to sham-operated or ischemia-reperfusion (I/R) groups. I/R was induced by occluding the superior mesenteric artery for 1 h, and the subsequent reperfusion was monitored for 3 h. For 5 min before reperfusion, the animals were mechanically ventilated with normoxic artificial air with or without 2.5% methane. The macrohemodynamics and small intestinal pCO2 gap changes were recorded and tissue superoxide and nitrotyrosine levels and myeloperoxidase activity changes were determined in intestinal biopsy samples. Structural mucosal damage was measured via light microscopy and HE staining.
  
  
  RESULTS
  Methane inhalation positively influenced the macrohemodynamic changes, significantly reduced the intestinal pCO2 gap changes and the magnitude of the tissue damage after reperfusion. Further, the intestinal myeloperoxidase activity, the superoxide and nitrotyrosine levels were reduced.
  
  
  CONCLUSIONS
  These data demonstrate the anti-inflammatory profile of methane. The study provides evidence that exogenous methane modulates leukocyte activation and affects key events of I/R-induced oxidative and nitrosative stress.
authors.affiliation: Szegedi Tudományegyetem, Általános Orvostudományi Kar Sebészeti Műtéttani Intézet 6720 Szeged Pécsi u. 6.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Varga
authors.forename: Dániel
authors.initials: D
authors.lastname: Erces
authors.forename: Eszter
authors.initials: E
authors.lastname: Tuboly
authors.forename: József
authors.initials: J
authors.lastname: Kaszaki
authors.forename: Miklós
authors.initials: M
authors.lastname: Ghyczy
authors.forename: Mihály
authors.initials: M
authors.lastname: Boros
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology*; D015415:Biomarkers / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D004195:Disease Models, Animal; D004285:Dogs; D006439:Hemodynamics / Q000187:drug effects*; D007249:Inflammation / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D007962:Leukocytes / Q000187:drug effects; D008697:Methane / Q000008:administration & dosage / Q000494:pharmacology*; D009195:Peroxidase / Q000378:metabolism; D011897:Random Allocation; D015427:Reperfusion Injury / Q000209:etiology / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D013481:Superoxides / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D015415:Biomarkers; D013481:Superoxides; D002245:Carbon Dioxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D009195:Peroxidase; D008697:Methane