GLUTATHIONE SYSTEM OF HUMAN RETINA - ENZYMATIC CONJUGATION OF LIPID-PEROXIDATION PRODUCTS

The major aspects of the glutathione (GSH)-related antioxidant defense of human retina are presented. These include concentration of GSH and activities of some GSH-dependent enzymes: glutathione peroxidase, glu tathione disulfide reductase, and glutathione S-transferase toward a b road spectrum substrate 1-chlor-2,4-dinitrobenzene and a toxic product of lipid peroxidation (4-hydroxynonenal). The presence of a relativel y high GSH concentration, GSH peroxidase activity, and GSH S-transfera se specific activity toward 4-hydroxynonenal in human retina might con stitute a central defense mechanism in inflammation-promoted oxidative stress and subsequent lipid peroxidation. The use of different substr ates for the determination of the GSH peroxidase activity showed no st atistically significant difference, thus suggesting the lack of Se-ind ependent GSH peroxidase in human retina. Large individual variations w ere obtained for GSH concentration and the different activities tested the apparent correlation with age of these findings is currently unde r investigation.