II. Effect of Ozone Inhalation on Nadide Phosphate Levels in Tracheal Mucosa

Abstract

Epithelial cell suspensions were prepared from rat trachea by the brush technique. The ratio of reduced nadide phosphate (NADPH) to oxidized nadide phosphate (NADP⁺) was determined by the enzymatic cycling method. In normal rat tracheal epithelium, this ratio was greater than one. This preponderance of NADPH over NADP+ agrees with other investigators’ findings for rat liver and brain. The NADPH/NADP⁺ ratio in rat tracheal epithelia, following 1 hour of ozone inhalation at 33 ppm, is not significantly different from the controls. Ozone destroyed NADPH, but not NADP⁺, in vitro. This experiment’s potential depends upon the availability of microanalytical methods for biological compounds possibly having crucial roles in toxic mechanisms. Its usefulness in elucidating the nature of the toxic-inhalant injury may be greater in studying tracheobronchial disease than diseases primarily affecting lung parenchyma.