Effects of hyperoxia on Wistar rat lungs

• Published in: Jornal brasileiro de pneumologia 2007-11, Vol.33 (6), p.655
• Main Authors: Valença, Samuel Dos Santos, Kloss, Milena Leonarde, Bezerra, Frank Silva, Lanzetti, Manuella, Silva, Fabiano Leichsenring, Porto, Luís Cristóvão
• Format: Article
• Language: Portuguese
• Subjects: Animals; Bronchoalveolar Lavage Fluid - chemistry; Disease Models, Animal; Edema - pathology; Hemorrhage - pathology; Hyperoxia - chemically induced; Hyperoxia - pathology; Lung - drug effects; Lung - pathology; Macrophages, Alveolar - pathology; Male; Neutrophils - pathology; Oxidative Stress - drug effects; Oxygen - administration & dosage; Oxygen - adverse effects; Pulmonary Alveoli - drug effects; Pulmonary Alveoli - pathology; Rats; Rats, Wistar; Time Factors
• ISSN: 1806-3756

To study the effects of short-term exposure to high oxygen concentrations (hyperoxia) on Wistar rat lungs. 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. 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%). Hyperoxia for 90' caused injury of the lung parenchyma, resulting in oxidative damage and inflammatory cell infiltration.