EFFECTS OF N-3 POLYUNSATURATED FATTY-ACIDS ON THE REACYLATION OF ARACHIDONIC-ACID IN PERITONEAL-MACROPHAGES

Mouse peritoneal macrophages mere prelabelled with [H-3]AA and activat ed ex vivo with phorbol myristate acetate (PMA) in the presence or abs ence of added n-3 polyunsaturated fatty acids (n-3 PUFA). The n-3 PUFA did not affect the release of [H-3]AA from stimulated macrophages. Ad ded AA, enhanced, in a dose-dependent manner, the amount of free [H-3] AA in the medium after activating the cells with PMA. Both n-3 PUFA an d AA were actively acylated into the lipids of PMA activated macrophag es, but the n-3 PUFA did not compete with reacylation of AA. In unstim ulated cells, in the absence of PMA, n-3 PUFA effectively competed wit h AA for acylation into membrane phospholipids. These studies suggest that distinct pools of AA exist in macrophages.