Oxidative effects on the glutathione enzyme systems

Abstract

Abstract Purpose Lens ageing is associated with oxidative processes, with photo‐oxidation as one of the stressors. Cataract has traditionally been viewed as a one‐way progressive event, but in vivo and in vitro animal studies on ultraviolet radiation‐induced cataract during the last years show repair capacity in the lens. Little is known about what these repair systems are and how they might be influenced by pharmaceuticals. The glutathione redox enzymes have critical antioxidative functions and are a potential target for pharmaceutical intervention. Methods Primary cultures of lens epithelial cells were obtained from mouse and human pediatric lens capsules. The cells were stressed with varying concentrations of hydrogen peroxide. The short‐term activity pattern of primary glutathione‐reducing enzymes and other glutathione‐associated enzymes were determined. Results The main picture was a concentration‐dependent decrease in enzyme activity within 15 minutes, with subsequent recovery within one hour. Conclusion The time frame for enzyme inhibition is co‐inciding with that of maximally efficient exposure time in ultraviolet radiation‐induced cataract.