Dietary effects of eicosapentaenoic and docosahexaenoic acid esters on lipid metabolism and immune parameters in Sprague-Dawley rats

Sprague-Dawley rats were fed eicosapentaenoic (EPA) and docosahexaenoic aci d (DHA) ethyl esters at the 2% level for 3 weeks to clarify their effects o n immune functions, In the rats fed EPA or DHA, serum cholesterol, triglyce ride, and phospholipid (PL) levels were significantly lower than those in t he rats fed safflower oil, In PL fractions of serum, liver, lung, splenocyt es, and peritoneal exudate cells (PEC), increases in linoleic and dihomo-ga mma -linolenic acid contents and a decrease in arachidonic acid (AA) conten t were observed in the rats fed EPA or DHA. In addition, the EPA content in creased in the rats fed EPA and DHA, In the rats fed EPA or DHA, a decrease of LTB4 productivity and an increase of LTB5 productivity were observed in the PEG, in response to the treatment with 5 muM calcium ionophore A23187 for 20 min. The changes in leukotriene production were more marked in EPA-f ed rats than in DHA-fed rats, These results suggest that dietary EPA affect s lipid metabolism and leukotriene synthesis more strongly than DHA.