Impact mechanisms of ozone at cell level

Mechanisms of toxic action and cellular defense against ozone were studied using an _in vitro model in which cell cultures can be exposed to gaseous compounds. Formation of fatty acid ozonides seems to be involved in the mechanism of toxic action. Cellular defense against ozone can be provided by a-tocopherol, ascorbic acid and glutathione. The protective role of glutathione cannot be ascribed to the glutathione peroxidase-catalyzed detoxification of lipid hydroperoxides. Glutathione rather functions in the detoxification of lipid ozonides, a reaction that may be catalyzed by glutathione S-transferases.