EFFECTS OF HIGH-FAT DIETS ON THE IMMUNE-RESPONSES OF PEYERS PATCH-IMMUNIZED RATS

Effects of dietary high fats on the immune responses of thoracic duct lymphocytes were investigated by comparing with phagocytic activity of alveolar macrophages (Mo) in rats immunized by intra-Peyer's patch in jection of keyhole lympet hemocyanin (KLH). The oils used in this expe riment were rich in either saturated fatty acid (SFA, lard oil) or pol yunsaturated fatty acid (PUFA, perilla seed oil). When stimulated with mitogens (PHA, Con A and LPS), blastogenesis of thoracic duct lymphoc ytes was significantly greater in KLH-immunized group than saline- tre ated one. Degree of the enhanced response to these mitogens was much m ore in rats fed high PUFA diet than high SFA diet. Number of IgA-antib ody presenting cells in thoracic duct lymph was increased following im munization of the Payer's patches with KLH in rats fed PUFA diet than SFA diet. Phagocytic activity of alveolar Mo was enhanced in KLH-treat ed rats compared to saline-treated rats, and then after stimulation wi th Mo-activating factor, their activity was further increased in high PUFA diet group than in high SFA diet one. These results suggest that high-dietary PUFA in Payer's patch-immunized rats is capable of more i ncreasing the immune responses of thoracic duct lymphocytes and sequen tially of enhancing phagocytic activity of alveolar Mo compared to hig h SFA.