Increased prostaglandin E₂ production by concanavalin A-stimulated splenocytes of old mice

Production of prostaglandin E₂ (PGE₂) was examined in splenocyte cultures of C57BL/6J mice aged between 1 and 34 months. A significant increase in PGE₂ production, in response to polyclonal stimulation by concanavalin A, was found after 24 and 48 h of incubation in all age groups. However, activated splenocytes taken from mice of the oldest group (28-34 months) produced 2- to 3-fold greater amounts of PGE₂, as compared with the younger groups, and a trend towards an age-associated increase was apparent from the age of 18 months onwards. No significant age-related difference in PGE₂ levels was observed in unstimulated cultures. The results obtained conform to the hypothesis that PGE₂ is involved in the age-related changes in lymphocyte functions. Increased PGE₂ production in response to mitogenic stimuli may affect the profile of cytokines and may limit cell-mediated immune responses in aging, such as lymphocyte proliferation and natural killer cell activity.