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Direct correlation of glutathione and ascorbate and their dependence on age and season in human lymphocytes

2000; Elsevier BV; Volume: 71; Issue: 5 Linguagem: Inglês

10.1093/ajcn/71.5.1194

1938-3207

Kevin J. Lenton, Hélène Therriault, A M Cantin, Tamàs Fülöp, Hélène Payette, J. Richard Wagner,

Coenzyme Q10 studies and effects

Endogenous reactive oxygen species appear to contribute to aging and cancer and dietary antioxidants, present in fruit and vegetables, counteract these effects. The objective was to examine the association between intracellular glutathione, ascorbate (vitamin C), and α-tocopherol (vitamin E) in human lymphocytes. The study group consisted of 240 healthy nonsmoking volunteers with an approximately equal number of male and female subjects subdivided into 3 age groups: 18–39, 40–59, and ≥60 y). Glutathione, glutathione disulfide, ascorbate, and α-tocopherol were measured in lymphocytes by HPLC. The average concentration of antioxidants in lymphocytes was 27 ± 8 nmol/mg protein for glutathione, 21 ± 8 nmol/mg protein for ascorbate, and 0.4 ± 0.2 nmol/mg protein for α-tocopherol. There was a strong positive correlation between glutathione and ascorbate (r = 0.62, P < 0.001). No correlation was observed for glutathione and ascorbate with α-tocopherol. The concentration of glutathione in lymphocytes was inversely correlated with age (r = −0.19, P < 0.01), as was that of ascorbate (r = −0.22, P < 0.01), with 10–20% lower values in elderly than in young and elderly subjects. The concentrations of glutathione in lymphocytes were as much as 25% higher and those of ascorbate were as much as 38% higher during the summer than during the winter. The seasonal variation of ascorbate in lymphocytes was described by a linear function for age and a periodic sine function for season. Glutathione and ascorbate are directly correlated in human lymphocytes.