An in vitro model of lung alveolar tissue was developed by growing rat lung epithelial cells of Type II origin on hydrated collagen gels and subsequently maintaining the cultures at an air/liquid interface. The cultures provide a system to expose lung cells directly to toxic aerosols, fumes and gases. Nitrogen dioxide (NO2) was used to test the responsiveness of the cultures to toxic gases. Exposure to NO2 resulted in cytotoxicity and morphological alterations similar to those found in vivo, but at lower doses. Cell viability was analyzed by trypan blue dye exclusion, clonal survival and 3H-lysine incorporation. Dose-response relationships were determined at NO2 concentrations from 0-6.0 ppm (one hr exposure, room temperature) using cell viability assays. Decreased cell viability also resulted from increasing the time of exposure to 6 ppm of NO2 for up to one hr. This lung cell test system provides a rapid and economical system for the short-term toxicological testing of toxic gases, fumes, and aerosols.
Aerosols Animals