Activity loss of glutathione synthesis enzymes associated with human subcapsular cataract

Abstract

Purpose: To assess the activities of the two enzymes required for glutathione synthesis, gamma-glutamylcysteine synthetase and glutathione synthetase, in various forms of human cataracts.

Methods: The Cooperative Cataract Research Group cataract classification method and standard enzyme assay procedures were used.

Results: An inverse relationship was shown between residual activity of each of the glutathione synthesis enzymes and degree of subcapsular cataract. A weaker inverse relationship existed between glutathione synthetase activity and supranuclear and nuclear cataracts. No other parameters yielded comparable correlations with the activity of either enzyme.

Conclusions: Activity loss of the glutathione synthesis enzymes is associated with human subcapsular cataract formation.