ABNORMAL MUCOUS CELL PHENOTYPE INDUCED BY NEUTROPHIL ELASTASE IN HAMSTER BRONCHI

Bronchial mucous cell metaplasia (MCM) is a histologic component of ch ronic mucus hypersecretion. The hamster model of elastase-induced MCM appears to involve an irreversible conversion of Clara cells to mucous cells. The present study questioned whether the mucous cells seen in hamster bronchi exposed to neutrophil elastase produce and maintain a form of glycoconjugate secretory product different from that normally found in mucous cells or Clara cells. Ultrastructural cytochemistry us ing the gold-labeled lectin HPA revealed a difference in the cell surf ace and stared secretory granules of elastase-derived mucous cells com pared to normal mucous cells and Clara cells at 3 weeks and 4 months f ollowing exposure. The results suggest that elastase irreversibly alte rs the glycoconjugate character of the Clara cells normally present so that they produce an abnormal form of mucus. Because secreted glycoco njugates can affect the rate of mucociliary clearance and receptor med iated binding of microorganisms, this change in phenotype may be invol ved in the pathogenesis of diseases associated with chronic mucus hype rsecretion in humans.