ACTIVITY LOSS OF GLUTATHIONE SYNTHESIS ENZYMES ASSOCIATED WITH HUMAN SUBCAPSULAR CATARACT

Purpose. To assess the activities of the two enzymes required for glut athione synthesis, gamma-glutamylcysteine synthetase and glutathione s ynthetase, in various forms of human cataracts. Methods. The Cooperati ve Cataract Research Group cataract classification method and standard enzyme assay procedures were used. Results. An inverse relationship w as shown between residual activity of each of the glutathione synthesi s enzymes and degree of subcapsular cataract. A weaker inverse relatio nship existed between glutathione synthetase activity and supranuclear and nuclear cataracts. No other parameters yielded comparable correla tions with the activity of either enzyme. Conclusions. Activity loss o f the glutathione synthesis enzymes is associated with human subcapsul ar cataract formation.