Abstract
Abstract: :
Purpose: Glutathione-S-transferase (GST) might be one enzyme associated in antioxidative defence system of human lenses. This study aimed to investigate the GST content of human lenses in different forms of cataract. Furthermore, the possible influence of diabetes was investigated. Methods: 58 human lenses with a mean age of 67.7 years (n=36 corticonuclear cataracts, n=22 mature cataracts; n=10 diabetic) were investigated. GST activity was measured spectrophotometrically by coupling of 1-chloro-2,4-dinitrobenzene (CDNB) or o-dinitrobenzol to glutathione to the method described by Habig. Statistics was performed by Mann-Whitney Test. Results: Mature cataracts showed a significant loss of GST-activity compared to corticonuclear cataracts (o-dinitrobenzol: 0.087±0.007 vs. 0.092±0.009 nmol/min, p=0.004; CDNB: 45.93±4.26 vs. 49.10±6.14 nmol DNB-GS/min, p=0.06). Dark brown lenses found to be significant lowered in GST activity compared to light-brown lenses (o-dinitrobenzol: p=0.005; CDNB: p=0.018). However, diabetic lenses showed very similar GST-activity compared to non-diabetic lenses (o-dinitrobenzol: 0.090±0,009 vs. 0.090±0.004 nmol/min; CDNB: 48.44±5.88 vs. 45.43±3.14 nmol DNB-GS/min). Conclusions: In human cataractous lenses a significant loss of GST-activity with increasing stage of cataract and lens coloration could be found. This might be associated with a loss of anti-oxidative capacity of the lens during cataract development.
Keywords: cataract • aging • diabetes