Acrolein: a respiratory toxin that suppresses pulmonary host defense.

Acrolein is a ubiquitous environmental pollutant that is known to cause respiratory tract injury and suppression of pulmonary host defense against infections in animal models. The mechanisms of acrolein-induced suppression of pulmonary host defense are not well understood. It has been generally believed that epithelial injury is responsible for the acrolein-caused decrease in resistance to infection. Emerging evidence suggests, however, that the alveolar macrophage is also a key target for acrolein-induced suppression of pulmonary host defense. It is likely that the combination of epithelial cell injury and inhibition of macrophage function may be responsible for acrolein-induced suppression of pulmonary host defense. To better assess the health risk of exposure to environmental levels of acrolein, more population-based studies are needed to monitor the levels of acrolein exposure and the adverse health effects associated with such exposures.