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 Concanava lin A (ConA), induced proliferation and lymphokine production, occur i n ad-libitum fed Brown Norway (AL BN) rats, Since caloric restriction (CR) extends lifespan, we expected that the age related changes in imm une parameters would be delayed by CR. CR does act to delay age-relate d changes in proliferation in response to ConA. In addition, CR postpo nes the plateau in ConA induced interferon (IFN) production seen after 23 months of age in AL rats, However, CR does not postpone the age-re lated decline in ConA induced interleukin-2 (IL-2) production. Therefo re, ConA induced IFN production maybe a good candidate as an early mar ker of physiologic aging, while ConA induced proliferative response is a possible candidate for a marker of late stages of aging.