Development of a cell culture model system for routine testing of substances inducing oxidative stress

The toxicological model of oxidative stress is a mechanism which is currently thought to be involved in the formation and development of many serious human diseases. Little is known about cellular responses to oxidative damage and the related specific toxicological properties of substances such as chemicals or components of the polluted urban atmosphere. On the basis of biological pathways involved in cellular antioxidative mechanisms, we developed a biological model for studying the oxidative properties of substances. This includes human lung cells and methods for biochemical analysis of cellular endpoints. Antioxidative and glycolysis-related enzyme activities (glutathione peroxidase, glutathione reductase, superoxide dismutase, catalase, phosphofructokinase, enolase, glucose-6-phosphate dehydrogenase), ATP/ADP/AMP and glutathione (oxidized and reduced) are determined. Routine testing of substances with high reproducibility and fast screening is provided by adapting methods for biochemical analysis ti determinations using cells grown on microtitre plates. First experiments with standard model substances inducing oxidative stress such as H2O2 and tert-butylhydroperoxide show that enzymatic activities can be measured with good reproducibility and their changes can be followed kinetically. The results indicate the relevance of the determined parameters for such toxicological events and the usefulness of the biological indicator system for routine testing.