title: Lung deflation impairs alveolar epithelial fluid transport in ischemic rabbit and rat lungs.
abstract: BACKGROUND
  Because the fluid transport capacity of the alveolar epithelium after lung ischemia with and without lung deflation has not been well studied, we carried out experimental studies to determine the effect of lung deflation on alveolar fluid clearance.
  
  
  METHODS
  After 1 or 2 hr of ischemia, we measured alveolar fluid clearance using 125I-albumin and Evans blue-labeled albumin concentrations in in vivo rabbit lungs in the presence of pulmonary blood flow and in ex vivo rat lungs in the absence of any pulmonary perfusion, respectively.
  
  
  RESULTS
  The principal results were: (1) lung deflation decreased alveolar fluid clearance while inflation of the lungs during ischemia preserved alveolar fluid clearance in both in vivo and ex vivo studies; (2) alveolar fluid clearance was normal in the rat lungs inflated with nitrogen (thus, alveolar gas composition did not affect alveolar fluid clearance); (3) amiloride-dependent alveolar fluid clearance was preserved when the lungs were inflated during ischemia; (4) terbutaline-simulated alveolar fluid clearance was preserved in the hypoxic rat lungs inflated with nitrogen; (5) lecithinized superoxide dismutase, a scavenger of superoxide anion, and N(omega)-nitro-L-arginine methyl ester, an inhibitor of nitric oxide, preserved normal alveolar fluid clearance in the deflated rat lungs.
  
  
  CONCLUSIONS
  Lung deflation decreases alveolar fluid clearance by superoxide anion- and nitric oxide-dependent mechanisms.
authors.affiliation: Respiratory Medicine, Basic Medical Science, and Department of Pharmacology, Kanazawa Medical University, Uchinade, Ishikawa, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sakuma
authors.forename: C
authors.initials: C
authors.lastname: Tsukano
authors.forename: M
authors.initials: M
authors.lastname: Ishigaki
authors.forename: Y
authors.initials: Y
authors.lastname: Nambu
authors.forename: K
authors.initials: K
authors.lastname: Osanai
authors.forename: H
authors.initials: H
authors.lastname: Toga
authors.forename: K
authors.initials: K
authors.lastname: Takahashi
authors.forename: N
authors.initials: N
authors.lastname: Ohya
authors.forename: T
authors.initials: T
authors.lastname: Kurihara
authors.forename: M
authors.initials: M
authors.lastname: Nishio
authors.forename: M A
authors.initials: MA
authors.lastname: Matthay
mesh_terms: D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport; D004848:Epithelium / Q000378:metabolism; D007511:Ischemia / Q000378:metabolism*; D008168:Lung / Q000098:blood supply* / Q000378:metabolism; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D011650:Pulmonary Alveoli / Q000378:metabolism*; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000494:pharmacology; D013726:Terbutaline / Q000494:pharmacology
chemical_list: D000584:Amiloride; D013482:Superoxide Dismutase; D013726:Terbutaline; D019331:NG-Nitroarginine Methyl Ester