The results suggest that initially higher levels of PUFA and plasmalogens in the tracheal effluent are associated with a reduced risk of developing BPD and are reduced during the first day of ventilation.

Lung surfactant is exposed to strongly oxidizing conditions. We examined the hypothesis that in lung, lipophilic antioxidants are secreted together with surfactant to counteract the peroxidation of surfactant constituents. Lung lavage and the subfractions of the alveolar surfactant contain the lipophilic antioxidants vitamin E, vitamin A, and plasmalogens. The specific radioactivity of vitamin E isolated from serum, lung homogenate, lamellar bodies, and lung lavage increased linearly up to 3 h after intraperitoneal application of [3H]tocopherol. [3H]tocopherol was secreted in situ together with [14C]palmitic acid-labeled phospholipid in response to isoproterenol. Type II cells cultured in presence of [3H]tocopherol or of [3H]cholecalciferol and [14C]palmitic acid responded to isoproterenol by a time-dependent increase in secretion of [3H]tocopherol and of 14C-labeled phospholipids but not of [3H]cholecalciferol. The isoproterenol-stimulated secretion of [3H]tocopherol and of 14C-labeled phospholipids by type II cells is inhibited by surfactant protein A. We conclude that the alveolar surfactant contains lipophilic antioxidants as integral constituents. [3H]tocopherol seems to be secreted together with surfactant.