title: [Effects of hyperoxia on Wistar rat lungs].
abstract: OBJECTIVE
  To study the effects of short-term exposure to high oxygen concentrations (hyperoxia) on Wistar rat lungs.
  
  
  METHODS
  Animals were divided into three groups exposed to hyperoxia for 10', 30' and 90' (O10', O30', O90', respectively), together with a control group (exposed to room air). The animals were sacrificed 24 h after exposure. Bronchoalveolar lavage was performed, and the lungs were removed for histological and stereological analysis.
  
  
  RESULTS
  In the O10', O30', and O90' groups, respectively and in comparison with the controls, we observed an increase in the numbers of macrophages (2169.9 +/- 118.0, 1560.5 +/- 107.0, and 1467.6 +/- 39.0 vs. 781.3 +/- 78.3) and neutrophils (396.3 +/- 35.4, 338.4 +/- 17.3, and 388.7 +/- 11.7 vs. 61.6 +/- 4.2), concomitant with an increase in oxidative damage (143.0 +/- 7.8%, 180.4 +/- 5.6%, and 235.0 +/- 13.7 vs. 100.6 +/- 1.7%). The histological and stereological analyses revealed normal alveoli and alveolar septa in the controls (83.51 +/- 1.20% and 15 +/- 1.21%), in the O10' group (81.32 +/- 0.51% and 16.64 +/- 0.70%), and in the O30' group (78.75 +/- 0.54% and 17.73 +/- 0.26%). However, in the O90' group, inflammatory cell infiltration was observed in the alveoli and alveolar septa. Red blood cells extravasated from capillaries to the alveoli (59.06 +/- 1.22%), with evidence of congestion, hemorrhage, and septal edema (35.15 +/- 0.69%).
  
  
  CONCLUSIONS
  Hyperoxia for 90' caused injury of the lung parenchyma, resulting in oxidative damage and inflammatory cell infiltration.
authors.affiliation: Departamento de Histologia e Embriologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil. samuelv@hotmail.com
authors.forename: Samuel Dos Santos
authors.initials: Sdos S
authors.lastname: Valença
authors.forename: Milena Leonarde
authors.initials: ML
authors.lastname: Kloss
authors.forename: Frank Silva
authors.initials: FS
authors.lastname: Bezerra
authors.forename: Manuella
authors.initials: M
authors.lastname: Lanzetti
authors.forename: Fabiano Leichsenring
authors.initials: FL
authors.lastname: Silva
authors.forename: Luís Cristóvão
authors.initials: LC
authors.lastname: Porto
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D004195:Disease Models, Animal; D004487:Edema / Q000473:pathology; D006470:Hemorrhage / Q000473:pathology; D018496:Hyperoxia / Q000139:chemically induced / Q000473:pathology*; D008168:Lung / Q000187:drug effects / Q000473:pathology*; D016676:Macrophages, Alveolar / Q000473:pathology; D008297:Male; D009504:Neutrophils / Q000473:pathology; D018384:Oxidative Stress / Q000187:drug effects*; D010100:Oxygen / Q000008:administration & dosage / Q000009:adverse effects*; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D010100:Oxygen