[Biochemical composition of a surfactant and its free radical processes in hyperbaric oxygenation and in the post-hyperoxic period].

Monitoring was made to examine the lungs. With this mode of hyperbaric oxygenation (0.3 MPa for 5 hours), rats developed mild oxygen intoxication which alleviated on day 3 and ceased on day 7 after its exposure. At the same time there were profound changes in the surfactant levels of protein, phospholipids, and cholesterol, which became normal on day 7 of postexposure. Chemiluminescence analysis and measurements of lipid peroxidation (PLO) products indicated that PLO rates in the surfactant decreased during hyperbaric oxygenation and remained at low levels within 24 hours of postexposure, whose cause might be activated by the antioxidative systems, as considered by the authors. However, on day 3 PLO enhances and on day 7 a new level of free-radical processes established, which was characterized by higher concentrations of free radicals and enhanced the activity of the antiradical systems.