Distribution of antileukoprotease in upper respiratory mucosa

Human respiratory tract secretions contain enzyme inhibitors derived from plasma and a low molecular weight, acid-stable protease inhibitor, antileukoprotease. The distribution of antileukoprotease in normal upper respiratory tract mucosa has been studied using an immunohistologic technique. The inhibitor was localized to the serous parts of the submucosal glands of the maxillary sinus and the trachea but was not demonstrable in mucous glands and goblet cells. It is concluded that the antileukoprotease found in respiratory tract secretions is produced locally in the submucosal serous glands.