Effects of oxygen-derived free radicals on type II pneumocytes in primary culture

After a brief review of oxygen-derived free radicals formation, cellular antioxidant equipment, and in vivo oxidant lung injury, the model of type II pneumocytes in primary culture is described with its characteristics and limitations. This model has been used to study either the in vivo or the in vitro effects of free radicals: the resistance of type II cells isolated from animals exposed to oxidants may be explained by their higher level of anti-oxidant enzymes. In contrast, type II cells isolated from control animals do not develop a resistance to the toxic effects on an in vitro exposure to free radicals. This discrepancy might be the result of a possible interaction of alveolar macrophages or fibroblasts with type II cells, which remains to be explored.