Age associated changes in mitogen induced proliferation and cytokine production by lymphocytes of the long-lived brown Norway rat.

The long-lived, inbred Brown Norway (BN) rat demonstrates an age associated decrease in lymphoproliferation in response to ConA; however, these declines only become apparent after the age of median survival, 31 months. Significant declines in IL-2 production after ConA stimulation also occur after median survival. In contrast, production of IFN after ConA stimulation increases with age in BN rats. This increase in IFN production begins about 12 months of age and plateaus at about median lifespan. The imbalance in IL-2 and IFN production may reflect a dysregulation that results in a decreased proliferative response of lymphocytes with increasing age.