Nitrogen Dioxide Effects on Alveolar Macrophages

Abstract

Rabbits were exposed to 5, 15, 25, or 50 ppm of nitrogen dioxide for three hours. Their alveolar cells were harvested and tested for phagocytic activity, rate of oxygen uptake, and hexosephosphate shunt activity. Other groups of animals were given parainfluenza 3 virus intrafracheally prior to NO₂ exposure in order to measure the effect of this gas on virus-induced resistance to rabbitpox virus. Virus-induced resistance and phagocytic activity were suppressed by 15 ppm of NO₂. In contrast, 50 ppm stimulated oxygen uptake and hexosephosphate shunt activity. Suppression of phagocytic activity and virus-induced resistance were observed to be the most sensitive indicators of NO₂ alterations of alveolar cells.