title: Low tidal volume mechanical ventilation and oxidative stress in healthy mouse lungs.
abstract: OBJECTIVE
  Mechanical ventilation (MV) itself can directly contribute to lung injury. Therefore, the aim of the present study was to investigate early biomarkers concerning oxidant/antioxidant balance, oxidative stress, and inflammation caused by short-term MV in healthy mouse lungs.
  
  
  METHODS
  Twenty male C57BL/6 mice were randomly divided into two groups: MV, submitted to low tidal volume (V T, 6 mL/kg) MV for 30 min; and spontaneous respiration (SR), used as controls. Lung homogenate samples were tested regarding the activity of various antioxidant enzymes, lipid peroxidation, and TNF-α expression.
  
  
  RESULTS
  In comparison with the SR group, the MV group showed a significant decrease in the activity of superoxide dismutase (≈35%; p < 0.05), together with an increase in the activity of catalase (40%; p < 0.01), glutathione peroxidase (500%; p < 0.001), and myeloperoxidase (260%; p < 0.001), as well as a reduction in the glutathione/oxidized glutathione ratio (≈50%; p < 0.05) and an increase in TNF-α expression in the MV group. Oxidative damage, assessed by lipid peroxidation, was also greater in the MV group (45%; p < 0.05).
  
  
  CONCLUSIONS
  Our results show that short-term low V T MV can directly contribute to lung injury, generating oxidative stress and inflammation in healthy mouse lungs.
authors.affiliation: Departamento de Histologia e Embriologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: Karla Maria Pereira
authors.initials: KM
authors.lastname: Pires
authors.forename: Adriana Correa
authors.initials: AC
authors.lastname: Melo
authors.forename: Manuella
authors.initials: M
authors.lastname: Lanzetti
authors.forename: Natália Vasconcelos
authors.initials: NV
authors.lastname: Casquilho
authors.forename: Walter Araújo
authors.initials: WA
authors.lastname: Zin
authors.forename: Luís Cristóvão
authors.initials: LC
authors.lastname: Porto
authors.forename: Samuel Santos
authors.initials: SS
authors.lastname: Valença
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D007249:Inflammation / Q000209:etiology / Q000473:pathology*; D015227:Lipid Peroxidation / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D018384:Oxidative Stress / Q000502:physiology*; D011897:Random Allocation; D012121:Respiration, Artificial / Q000009:adverse effects* / Q000379:methods; D018709:Statistics, Nonparametric; D013990:Tidal Volume / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*; D055397:Ventilator-Induced Lung Injury / Q000209:etiology* / Q000378:metabolism / Q000473:pathology
chemical_list: D015415:Biomarkers; D014409:Tumor Necrosis Factor-alpha