title: Hypercapnic acidosis minimizes endotoxin-induced gut mucosal injury in rabbits.
abstract: OBJECTIVE
  Recent evidence demonstrated that hypercapnic acidosis due to lung protective strategy was not only permissive but also even therapeutic for injured lung. Since the effects of hypercapnic acidosis on extra-pulmonary organs remain to be clarified, we tested the hypothesis that hypercapnic acidosis protects gut mucosal barrier function by modulating inflammation in a rabbit model of endotoxemia.
  
  
  METHODS
  Prospective randomized animal study.
  
  
  METHODS
  University research laboratory.
  
  
  METHODS
  Male New Zealand white rabbits.
  
  
  METHODS
  Thirty-two animals were randomly allocated into two groups: normocapnia (n = 17) and hypercapnia (n = 15). The latter group received F(I)CO(2) 5% under mechanical ventilation to achieve hypercapnia throughout the study periods, whereas the former with F(I)CO(2) 0%.
  
  
  RESULTS
  Arterial blood gas, intramucosal pH (pHi) and portal blood flow were assessed at baseline, 2-h and 4-h infusion of lipopolysaccharide. At 4 h, ileal myeloperoxidase (MPO) activity and intestinal permeability were measured. The animals in the hypercapnia group showed apparent hypercapnic acidosis and progressive intramucosal acidosis at 4 h, accompanied by significantly lower intestinal permeability versus normocapnia group. Ileal MPO activity was comparable between the study groups.
  
  
  CONCLUSIONS
  Hypercapnic acidosis attenuates endotoxin-induced gut barrier dysfunction possibly through neutrophil-independent mechanisms.
authors.affiliation: Department of Anesthesiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. morisaki@z8.keio.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Morisaki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yajima
authors.forename: Yoko
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Takeshi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Michiko
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Katori
authors.forename: Saori
authors.initials: S
authors.lastname: Hashiguchi
authors.forename: Junzo
authors.initials: J
authors.lastname: Takeda
mesh_terms: D000142:Acidosis, Respiratory / Q000503:physiopathology*; D000818:Animals; D018988:Bacterial Translocation / Q000502:physiology*; D019446:Endotoxemia / Q000503:physiopathology / Q000517:prevention & control*; D006935:Hypercapnia / Q000503:physiopathology*; D007413:Intestinal Mucosa / Q000201:enzymology / Q000502:physiology*; D008297:Male; D009195:Peroxidase / Q000032:analysis; D011817:Rabbits; D011897:Random Allocation; D013152:Splanchnic Circulation / Q000502:physiology
chemical_list: D009195:Peroxidase