PHENOTYPIC VARIATION IN HAMSTER BRONCHIAL MUCOUS CELLS INDUCED BY DIFFERENT AIRWAY IRRITANTS

Chronic mucus hypersecretion (CMH), a common feature of various obstru ctive pulmonary diseases, is caused by a variety of airway irritants. Bronchial mucous cell metaplasia (MCM), a histological correlate of CM H, can be induced in hamster airways by a number of different irritant s. Previous studies with the hamster model suggest that the secretory cell response to different agents is not stereotyped but can vary in t he type of mucus glycoconjugate produced. The present ultrastructural study was conducted therefore to provide quantitative evidence of phen otypic variation in mucous cells induced independently by exposure to the metaplastic agents elastase and acid. HPA-gold lectin cytochemistr y revealed an increase in N-acetyl galactosamine at the cell surface a nd secretory granules of mucous cells in elastase-treated vs. acid-tre ated animals. Although there was no quantitative difference between th e acid-treated and untreated groups, a difference in the pattern of bi nding within granules indicated variation in the secretory product. Be cause mucus glycoconjugates serve as attachment sites for specific pat hogens, phenotypically distinct mucous cells may promote differential microbial colonization. In humans therefore, variation in the severity and progression of CMH may be due in part to secretory cell susceptib ility and response to different pathogenic stimuli.