Serum Clara cell protein (CC16): a new valid marker of the distal airway damages caused by air pollutants in rats.

Cell count, LDH, total protein, Clara cell protein (CC16) and lysozyme in bronchoalveolar lavage fluid (BAL) and serum were determined in rats. 30-50 ppm sulfur dioxide for 4 h. 12 h and 2 week exposure didn't produce any change of above parameters. 1.0 ppm, 0.5 ppm, 0.38 ppm, 0.25 ppm and 0.20 ppm ozone for 7 h exposure tests were performed. CC16, total protein and LDH in BAL had significantly changes in BAL in ozone groups. Only serum CC16 showed significant increase among ozone groups. Both BAL and serum CC16 were of the best exposure-response relationship with ozone concentration. The change of BAL fluid reached high peak 18-24 h after ozone exposure. Serum CC16 seemed to be a valid marker of the distal airway damages caused by air pollutants.