Blood glutathione: a biochemical index of life span enhancement in the diet restricted Lobund-Wistar rat.

These experimental results demonstrate that dietary restriction in both conventional and germfree rats results in enhanced longevity compared to fullfed animals. This increase in median survival age was due to a delay of 8 months in the onset of mortality in the restricted rats. Thereafter the aging rates of the short-lived subpopulations were the same for both groups. However, the aging rate of the long-lived restricted subpopulation was greater. The blood glutathione profiles demonstrated that a GSH deficiency of aging occurred in both the restricted and the long-lived groups. These data confirmed in the rat the findings observed previously in mosquito, mouse and man and verified the generality of the GSH and longevity relationship. Of special interest is that the blood glutathione levels were consistently higher at all ages of the restricted compared to fullfed rats and decreased more slowly during senescence. These findings indicate a direct relationship between enhanced GSH status and increased longevity due to dietary restriction. Further this suggests that glutathione may be a molecular mechanism for the diet restriction and longevity phenomenon.