Glutathione and glutathione-related enzymes in human cataractous lenses.

Glutathione and its related enzymes were measured for normal and cataractous human lenses. Glutathione decreased progressively with the development of cataracts. This decrease was more pronounced in the nucleus than in the capsule-epithelia of cataractous lenses. Glutathione reductase in nuclear extracts was relatively unchanged during cataract progress, while glutathione synthetase was significantly low in the advanced stages of cataracts. gamma-Glutamylcysteine synthetase was not measurable in the nuclei of cataractous lenses.