Improvement of mucosal pathology of the sinuses after exposure to sulfur dioxide by nebulization of S-carboxymethylcysteine.

Since s-carboxymethylcysteine (S-CMC) can directly enhance the ciliary activity in the maxillary sinus mucosa of patients with chronic sinusitis in the absence of significant organic changes of ciliated cells, the nebulization therapy using this medicine might be more effective in the treatment of chronic sinusitis than oral administration of the medicine. The safety of using 0.5–10% of S-SMC as a medicine for nebulization has been experimentally established. The present study was designed to experimentally examine the effectiveness of nebulization using 0.5–10% of S-CMC solution in the treatment of experimental chronic sinusitis in rabbits recurrently exposed to 20 ppm of sulfur dioxide. Thirty-three healthy rabbits were used; 3 of them were used as controls. The remaining 30 were exposed to 20 ppm of sulfur dioxide for 4 h a day for 4 successive weeks. Twelve animals were not treated with any medication during the post-exposure period, and sacrificed at 24 h or 15 days after completion of the final expo...