Enzymatic Determination of Reduced and Oxidized Glutathione in Bovine Lenses of Different Ages and Their Distribution in Lens Equator and Nucleus

Abstract

Simultaneous determination of reduced (GSH) and oxidized (GSSG) glutathione in bovine lenses and single lens parts can be performed by way of enzymatic methods in a single step. GSH is transformed with methylglyoxal to S-lactoyl-GSH by S-lactoyl-glutathione-methylglyoxal-lyase (EC 4.4.1.5), and GSSG to GSH by way of glutathione-reductase (EC 1.6.4.2) with NADPH. The presence of cystein does not influence the reaction. The values obtained are compared with those reported in the literature. The age-dependent changes are more notable with GSSG than with GSH content. There is a decrease of the oxidized form in the equator and an increase in the nucleus. Accordingly, the ratio of GSSG between equator and nucleus decreases by about 50% in 10-year-old lenses compared with that in 2-year-old lenses.