GLUTATHIONE IN HUMAN PLASMA - DECLINE IN ASSOCIATION WITH AGING, AGE-RELATED MACULAR DEGENERATION, AND DIABETES

Blood samples were analyzed for GSH and GSH redox state in 40 age-rela ted macular degeneration (ARMD) patients (> 60 y), 33 non-ARMD diabeti c patients (> 60 years), 27 similarly aged non-ARMD and nondiabetic in dividuals (> 60 years), and 19 younger individuals (< 60 years) withou t ARMD or diabetes. Results showed a significantly lower plasma GSH in older individuals (ARMD, diabetes, and controls) than in younger indi viduals (p < .01). Total GSH (GSHt) obtained following treatment with dithiothreitol was significantly lower only in diabetic cases (p < .05 ) but also approached significance for ARMD cases (p = .089). Estimati on of redox potential indicated that the plasma GSH pool is considerab ly more oxidized in all of the older groups. Analyses of whole blood G SH showed that GSH was significantly lower in diabetic cases compared to the other groups, but did not reveal any difference associated with age or ARMD. In contrast, GSSG in whole blood was significantly highe r in the older groups compared to the younger controls. The results su ggest that in studies of age-related pathologies, oxidation of GSH may be a more important parameter than a decline in pool size, while in s pecific pathologies such as diabetes, both oxidation and a decline in pool size may be important. (C) 1998 Elsevier Science Inc.