Ultrastructure of pulmonary alveolar macrophages in situ in lungs from rats exposed to ozone.

Abstract

Previous studies of the effects of ozone on pulmonary alveolar macrophages were conducted on cells obtained by bronchoalveolar lavage. The ultrastructure of pulmonary alveolar macrophages were examined in situ in lung tissue of rats exposed to 3 ppm of ozone for 4 hours. Macrophages in the lungs immediately after exposure resembled those in lungs of unexposed animals. These macrophages had active pseudopodia and intact cellular organelles. Three types of membrane-bound cytoplasmic inclusions and one unbound type were present. Twelve hours after exposure to ozone, the number of observed macrophages had doubled. In addition to a normal macrophage population, there were approximately equal numbers of macrophages containing large granular cytoplasmic inclusions that were regarded as Being the result of extensive phagocytic activity. It was concluded that this regimen of ozone exposure did not produce ultrastructurally detectable damage to pulmonary alveolar macrophages in situ within alveoli.