This study evaluated the role of lipid peroxidation in chondrocytes in the pathogenesis of cartilage aging and osteoarthritis (OA). An in vitro model with [(3)H]proline labeled matrix proteins was used to study the role of chondrocyte-derived ROS on the cartilage matrix. They exposed the model to different substances, such as hydrogen peroxide, catalase or superoxide dismutase and vitamin E, and measured the released of the labeled matrix. They got in vitro evidence relating the oxidation and degeneration of cartilage matrix collagen to chondrocyte lipid peroxidation and the preventive role of vitamin E.