Age-associated changes in mitogen-induced lymphoproliferation and lymphokine production in the long-lived brown-Norway rat: effect of caloric restriction

We have previously demonstrated that age-related declines in Concanavalin A (ConA), induced proliferation and lymphokine production, occur in ad-libitum fed Brown Norway (AL BN) rats. Since caloric restriction (CR) extends lifespan, we expected that the age related changes in immune parameters would be delayed by CR. CR does act to delay age-related changes in proliferation in response to ConA. In addition, CR postpones the plateau in ConA induced interferon (IFN) production seen after 23 months of age in AL rats. However, CR does not postpone the age-related decline in ConA induced interleukin-2 (IL-2) production. Therefore, ConA induced IFN production maybe a good candidate as an early marker of physiologic aging, while ConA induced proliferative response is a possible candidate for a marker of late stages of aging.