THE RESPONSE OF GUINEA-PIG AIRWAY EPITHELIAL-CELLS AND ALVEOLAR MACROPHAGES TO ENVIRONMENTAL-STRESS

Cells lining the respiratory tract form an interface between the organism and the external environment and are repeatedly exposed to physical, chemical, and metabolic stresses. We examined the response of cultured guinea pig tracheal epithelial cells and alveolar macrophages to various forms of stress, including clinically and environmentally relevant metabolic stresses such as ozone and acid exposure. Classic stress treatments such as heat shock and sodium arsenite treatment induced the synthesis of 28, 32, 72, 73, 90, and 110 kD stress proteins similar to those observed in other cell types. In contrast, no significant changes in the pattern of protein synthesis were detected after exposure to ambient concentrations of ozone, although ozone exposure caused significant cytotoxicity to both cell types. Another potent oxidant, hydrogen peroxide, similarly did not induce appreciable stress protein synthesis. However, surface acidification of tracheal epithelial cells and alveolar macrophages caused the induction of 72 and 78 kD stress proteins. While stress proteins may play a role in the response of respiratory cells to certain injuries such as hyperthermia and surface acidification, they may not be important in the defense against ozone or other forms of oxidative injury.