Dietary effect of EPA-rich and DHA-rich fish oils on the immune function of Sprague-Dawley rats

The dietary effect of fish oils (FOs) rich in eicosapentaenoic acid (EPA) o r docosahexaenoic acid (DHA) on the immune function of Sprague-Dawley rats was compared with that of safflower oil. After 3 weeks of feeding at the 10 % level of a dietary fat, the Ige and IgM production by splenocytes and Ige production by mesenteric lymph node (MLN) lymphocytes were significantly h igher in the FO-fed rats, while no significant difference was found in IgA or IgE productivity by both the spleen and MLN lymphocytes, In the FO-fed r ats, peritoneal exudate cells released a lower amount of LTB4, reflecting t heir lower arachidonic acid level, and a higher amount of LTB5, reflecting their higher EPA level in phospholipids. On these EPA-rich FO exerted a str onger effect than DHA-rich FO immune functions.