Ventila？？o mecanica com baixo volume corrente e estresse oxidativo em pulm？es saudáveis de camundongos

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 (vt, 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 vt mv can directly contribute to lung injury, generating oxidative stress and inflammation in healthy mouse lungs.