Incorporation of [1-14C]arachidonic and [1-14C]eicosapentaenoic acids into the phospholipids of peripheral blood neutrophils from the plaice, Pleuronectes platessa L.

The incorporation of [1-14C]arachidonic acid and [1-14C]eicosapentaenoic acids into phospholipids was studied in peripheral blood neutrophils from plaice, a marine fish whose lipids are rich in (n-3) polyunsaturated fatty acids. The incorporation of both labelled fatty acids into phospholipids was approximately equal when presented individually, and at equal concentration, to the cells. Arachidonic acid was relatively preferred when both acids were present in the incubations. When incorporation was expressed per unit mass of phospholipid class, the order of incorporation was PI greater than PC greater than PE greater than PS greater than sphingomyelin for both fatty acids. However, the specificity for incorporation into PI was significantly greater with arachidonic acid. Eicosapentaenoic acid was incorporated into PC to a greater extent than arachidonic acid. The results are discussed in relation to the possible roles of arachidonic acid and eicosapentaenoic acid in polyunsaturated fatty acid metabolism in plaice neutrophils.