Effects of single and combined, subchronic exposure to ozone and soot particles on pulmonary surfactant phospholipids and associated protein A and on surface activity in rat lung lavage fluid

It has been shown that the pulmonary surfactant system being important for lung mechanics as well as for non-specific alveolar defense mechanisms is affected by a variety of inhaled pollutants. Seven-week-old, adult male Wistar rats were subchronically exposed to either ozone or soot particles or a combination of both. Soot particles were instilled intratracheally and whole body ozone exposure performed in stainless steel inhalation chambers. At end exposure lung lavage fluid (LLF) was collected, surfactant phopholipid content determined by thin layer chromatography and surfactant-associated protein A (SP-A) assessed by ELISA. LLF surface tension measurements were performed using the pulsating bubble surfactometer. From these results we conclude that exposure to soot particles may affect pulmonary surfactant in rats to a greater extent than exposure to ozone at a high ambient concentration.