Abstract
The potential for vitamin E to modulate prostaglandin metabolism and alter immune response in aged mice was studied. Semi-purified diets containing 30 ppm or 500 ppm dl-α-tocopheryl acetate (VitE) were fed for 6 weeks to young (3 months) and old (24 months) C57BL/6J mice. Delayed hypersensitivity skin test to DNFB and the proliferative response of splenocytes to T- and B-cell mitogens were assessed. Ex-vivo synthesis of Prostaglandin E2 (PGE2) was measured in spleen homogenates and serum vitamin E was measured by HPLC. Vitamin E supplementation of aged mice enhanced percent ear swelling to DNFB as well as the mitogenic response of splenocytes to Con A and LPS (P < 0.05). Furthermore, spleen homogenates from old mice fed 30 ppm VitE had a significantly higher PGE2 level than young mice fed 30 ppm VitE and old mice fed 500 ppm VitE (3.20 ± 0.07 μg/g vs. 2.60 ± 0.08 and 2.3 ± 0.10, respectively). Thus, the vitamin E enhanced immune response of aged mice appears to be mediated by decreased prostaglandin synthesis.