SHORT-TERM OZONE EXPOSURE AFFECTS THE SURFACE-ACTIVITY OF PULMONARY SURFACTANT

The effects of short-term ozone exposure on the lung function and surf ace activity of surfactant subtypes isolated from rat lung lavage were studied. Rats were exposed to 0.8 ppm ozone for 2 or 12 hr. The surfa ce activity of surfactant was affected by ozone exposure, whereas dist inct morphological changes in bronchoalveolar lavage or in the surfact ant subtypes were not observed. Adsorption experiments indicated that bronchoalveolar lavage from rats exposed for 12 hr to ozone remained a t lower equilibrium surface pressures than lavage from control rats. T hese observations suggest interference of inflammatory proteins with t he surface film. Extracted surfactant, containing only lipids and surf actant proteins B and C, had a decreased adsorption rate after ozone e xposure. These results suggest that the activity of one or both of the hydrophobic surfactant proteins (SP-B and SP-C) was affected by ozone . (C) 1997 Academic Press.