Sulfur Dioxide Induced Bronchitis in Rats

Abstract
The effects of subchronic inhalation of 300 ppm and 400 ppm SO2 gas on airway mucus production and the distribution and density of respira­tory tract goblet cells was examined in rats. The changes in the goblet cell pop­ulation and mucus hypersecretion were examined over a 6-week period, with interim sacrifices at 3 and 4 weeks. Subacute exposure to 300 ppm SO2 pro­duced a bronchitic syndrome in rats similar to that observed in human bron­chitis. Inhalation of 300 ppm SO2 produced predominantly a large airway mucus cell hyperplasia with practically no loss in cellularity, or ablation as was observed with 400 ppm. In addition, the inhalation of both 300 ppm and 440 ppm SO2 induced a hypersecretion of mucus resulting in mucus accumila­tion throughout the respiratory tract.