Biochemical changes in rat lungs after exposure to nitrogen dioxide

Abstract

Sixty‐day‐old wale, specific pathogen‐free rats were exposed continuously to 5 or 15 ppm NO₂ for 1–7 d. Lung tissue from exposed and control rats was then analyzed for biochemical and enzymatic parameters. The exposure resultedin increased lung enzymatic activities, including elevated protein and DNA contents andnonprotein sulfhydryl levels. Biochemical and enzymatic paramters generally increased maximally after 4 d and remained elevated for up to 7 d of continued exposure. The magnitude of these increases was higher for 15 than for 5 ppm NO₂. The increases in biochemical and enzymatic parameters may have occurred in response to NO₂‐induced lung injury.