Effect of nitrogen dioxide exposure on cyclic GMP in rat lung.

In vivo exposure of rats to 10 ppm nitrogen dioxide (NO2) for 6 h caused approx. 5-fold increase in the content of cyclic GMP in lung tissue. This increased cyclic GMP level lasted up to 24 h but returned to the normal level within 2 days, even when the NO2 exposure continued. This increase in the content of cyclic GMP of lung tissue by NO2 exposure was observed in both young and aged rats. There were no statistically significant changes in the content of cyclic AMP in lung tissue.