Fig. 3. OA chondrocytes have a diminished capacity to repair oxidative damage.
Primary human chondrocytes from OA patients and normal donors were exposed to 300 µM of peroxynitrite (panel A) or 20 mU xanthine oxidase /0.5 mM hypoxanthine for 30 min and allowed to repair for 6 and 24 h. Cells were lysed, DNA was isolated and subjected to Southern blot analysis. The results were obtained from a minimum of 7 independent experiments, and the values displayed represent the mean break frequency ± SEM. * indicates a significant difference (P<0.05) between OA chondrocytes and those isolated from normal donors.