Natural surfactant combined with superoxide dismutase and catalase decreases oxidative lung injury in the preterm lamb.

We performed a randomized study in preterm lambs to assess the hypothesis that treatment with a natural surfactant combined with superoxide dismutase (SOD) and catalase (CAT) might decrease pulmonary oxidative stress in an animal model of respiratory distress syndrome (RDS). Animals received 200 mg/kg of porcine natural surfactant or 200 mg/kg of natural surfactant combined with 2 mg/ml of SOD and 3,000 U/ml of CAT. Lung tissue oxidation was studied by measuring total hydroperoxide (TH), advanced oxidation protein products (AOPP), and non-protein bound iron (NPBI) in bronchial aspirate samples. In addition, the animal's lung mechanics were evaluated. TH, AOPP, and NPBI were lower in the groups treated with surfactant plus SOD and CAT than in the surfactant group, while lung mechanics did not vary. We concluded that natural surfactant combined with SOD and CAT is effective in reducing the oxidative lung stress in an animal model of RDS.