X-ray effects on lens DNA-implications of superoxide (O(2))

The photochemical generation of superoxide (O(2)) during in vitro exposure of bovine lenses induced damage in the structure of lens DNA as indicated by hyperchromicity and Tm measurements. The damage in lens DNA was significantly protected by the inclusion of superoxide dismutase (SOD), glutathione (GSH) and ascorbate in the incubation medium before X-ray exposure. The protection by SOD, GSH and ascorbate occurred due to their interaction with O(2) radicals. These results thus indicate the deleterious effect of O(2) in lens physiology and the protective role of such compounds against radiation damage.