Methods to Study Interactions Between Inhaled Substances and Epithelium of the Respiratory Tract in Vitro

Epithelium lining the tracheobronchial tree represents the first cells with which particulates, gases, microbes, etc., come into contact upon inhalation. Thus, interactions between such inhaled substances and epithelial cells probably are integral to the pathogenesis of several occupational or environmental - related pulmonary lesions, yet such interactions have not yet been elucidated fully. Many published studies have described patterns of deposition within extra- and intrapulmonary airways and alveolar ducts, and histologic and ultrastructural changes in epithelium in vivo in response to inhalation and deposition. However, our knowledge of specific structural and functional responses of airway epithelium on a cellular level is limited, since exposures of animals in vivo or even tissues in situ do not allow for studying intracellular responses, especially subtle sublytic alterations which could be the basis for subsequent pathogenic responses. For this reason, investigators have utilized cell culture systems to examine intracellular mechanisms related to responses of respiratory epithelium to deleterious substances which may be inhaled in an occupational or environmental setting.