GLUTATHIONE DISULFIDE VARIABILITY IN NORMAL HUMAN BLOOD

A prevailing opinion is that glutathione disulfide (GSSG) levels in hu man blood are very low, but many studies have reported variable result s. Therefore, our objective was to determine valid processing conditio ns for GSSG measurement and apply them to normal human blood samples. Reproducibility and stability of GSSG were demonstrated in acid extrac ts of a single sample of fresh whole blood by repetitive measurements during a 6-h period in which the %CVs were <10. In contrast, in normal subjects tested repeatedly over several years, GSSG values ranging fr om <2 to 166 nmol per 10(10) red blood cells were obtained and the ove rall %CV was 46. Lower GSSG values were obtained in hemolysates and ul trafiltrates. Thus, these results indicate that blood GSSG concentrati ons differ due to biological variation using optimal processing condit ions. (C) 1994 Academic Press, Inc.