Direct correlation of glutathione and ascorbate and their dependence on age and season in human lymphocytes.
BACKGROUND
Endogenous reactive oxygen species appear to contribute to aging and cancer and dietary antioxidants, present in fruit and vegetables, counteract these effects.


OBJECTIVE
The objective was to examine the association between intracellular glutathione, ascorbate (vitamin C), and alpha-tocopherol (vitamin E) in human lymphocytes.


METHODS
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 alpha-tocopherol were measured in lymphocytes by HPLC.


RESULTS
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 alpha-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 alpha-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.


CONCLUSIONS
Glutathione and ascorbate are directly correlated in human lymphocytes.
Lenton
K J
KJ
Centre de Recherche, Institut Universitaire de Gériatrie de Sherbrooke, Sherbrooke, Canada.
Therriault
H
H
Cantin
A M
AM
Fülöp
T
T
Payette
H
H
Wagner
J R
JR
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood*; D001205:Ascorbic Acid / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005978:Glutathione / Q000097:blood*; D019803:Glutathione Disulfide / Q000097:blood; D006801:Humans; D016018:Least-Squares Analysis; D016014:Linear Models; D008214:Lymphocytes / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D012621:Seasons; D014810:Vitamin E / Q000097:blood
D014810:Vitamin E; D005978:Glutathione; D001205:Ascorbic Acid; D019803:Glutathione Disulfide