AGE-RELATED CYSTEINE UPTAKE AS RATE-LIMITING IN GLUTATHIONE SYNTHESIS AND GLUTATHIONE HALF-LIFE IN THE CULTURED HUMAN LENS

被引:70
作者
RATHBUN, WB
MURRAY, DL
机构
[1] Ophthalmology Department, University of Minnesota, Minneapolis
关键词
REDUCED GLUTATHIONE; OXIDIZED GLUTATHIONE; HUMAN LENS CULTURE; BUTHIONINE SULFOXIMINE; GLUTATHIONE SYNTHESIS; RATE-LIMITING FACTOR; CYSTEINE METABOLISM; GLUTATHIONE HALF-LIFE;
D O I
10.1016/0014-4835(91)90075-P
中图分类号
R77 [眼科学];
学科分类号
100212 ;
摘要
The study included human lenses of ages ranging from newborn to 92 years. Protein-free reduced glutathione decreased 14-fold, whereas protein-free oxidized glutathione increased 2·6-fold with increasing age. l-Cyst(e)ine uptake g-1 lens of very old cultured lenses decreased 70% from that exhibited in newborn lenses, demonstrating a marked decline of l-cyst(e)ine uptake as a function of age. In these same lenses the synthesis of reduced glutathione (μmol g-1 lens) decreased 73% with age. It was concluded that the glutathione decrease observed in the aging human lens was associated with decreased uptake of l-cyst(e)ine, decreased glutathione synthesis and possibly an increase in protein-free oxidized glutathione. The high correlation of l-cyst(e)ine uptake and glutathione synthesis supports the hypothesis that l-cyst(e)ine uptake is a rate-limiting factor of glutathione synthesis in the intact human lens. By the use of buthionine sulfoximine, the half-life of glutathione was estimated to be 90 hr in the cultured human lens. © 1991.
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页码:205 / 212
页数:8
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