title: Hyperoxia exposure impairs surfactant function and metabolism.
abstract: OBJECTIVE
  To evaluate the effects of hyperoxia exposure on lung function and the endogenous surfactant system in spontaneously breathing adult rats.
  
  
  METHODS
  Analysis of the pulmonary surfactant system isolated from adult rats following exposure to > 90% oxygen or room air for 48 or 72 hrs.
  
  
  METHODS
  A basic science research laboratory in a university setting.
  
  
  METHODS
  Sixty pathogen-free Sprague-Dawley rats.
  
  
  METHODS
  Exposure to > 90% oxygen for 72 hrs.
  
  
  RESULTS
  Exposure to > 90% oxygen for 72 hrs resulted in significant lung dysfunction and an increase in neutrophils and total protein concentrations within the airspace compared with animals exposed to room air or 48 hrs of 90% oxygen exposure. Total alveolar surfactant and large aggregate pool sizes were increased after 72 hrs of hyperoxia compared with the other groups, and there was evidence of lipid peroxidation within these large aggregate subtractions. The biophysical function of large aggregate isolated from 72-hr hyperoxia-exposed animals was also impaired and converted into small aggregate forms faster than large aggregate from normoxia-exposed animals when assessed using in vitro surface area cycling techniques.
  
  
  CONCLUSIONS
  Oxidative stress on the endogenous surfactant system may represent an important mechanism contributing to the surfactant dysfunction and abnormal surfactant metabolism associated with hyperoxia-induced lung injury.
authors.affiliation: Department of Medicine, Lawson Health Research Institute, St. Joseph's Health Centre, The University of Western Ontario, London, Ontario, Canada.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Zenri
authors.forename: Karina
authors.initials: K
authors.lastname: Rodriquez-Capote
authors.forename: Lynda
authors.initials: L
authors.lastname: McCaig
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Yao
authors.forename: Angela
authors.initials: A
authors.lastname: Brackenbury
authors.forename: Fred
authors.initials: F
authors.lastname: Possmayer
authors.forename: Ruud
authors.initials: R
authors.lastname: Veldhuizen
authors.forename: Jim
authors.initials: J
authors.lastname: Lewis
mesh_terms: D000208:Acute Disease; D000327:Adsorption; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D004195:Disease Models, Animal; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D018496:Hyperoxia / Q000150:complications*; D007958:Leukocyte Count; D015227:Lipid Peroxidation; D008170:Lung Compliance; D055370:Lung Injury; D008297:Male; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism; D018384:Oxidative Stress; D010100:Oxygen / Q000009:adverse effects*; D011663:Pulmonary Surfactants / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012128:Respiratory Distress Syndrome / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D013990:Tidal Volume; D013997:Time Factors
chemical_list: D011663:Pulmonary Surfactants; D010100:Oxygen