Effects of oxidant air pollutants on pulmonary surfactant using two isolation procedures.

Approximately three decades ago, pulmonary surfactant (PS) was shown to lower the surface tension of the liquid layer lining the lung's alveolar surface. It is important in preventing alveolar collapse and pulmonary edema and abnormalities is PS are associated with hyaline membrane disease in newborns and respiratory distress syndrome in adults. A number of studies have investigated the effects of oxidant exposure on the chemical composition of lavage fluids from which cellular debris has been removed by low speed centrifugation; however, few of these studies have incorporated additional centrifugation steps for isolation of PS from the lavage fluid. The goal of our work was to determine whether or not additional centrifugation steps in the isolation of PS from the lavage fluid would alter either the fatty acid composition, or the observed changes in it, on exposure to the combination of the air pollutants, O{sub 3} and NO{sub 2}. We found that both the initial composition and the observed changes on exposure were sensitive to the use of additional sucrose density gradient centrifugation (SDGC) steps.