EFFECT OF DEGREE OF UNSATURATION IN DIETARY FATTY-ACIDS ON ARACHIDONIC-ACID MOBILIZATION BY PERITONEAL-MACROPHAGES

Cells from rats fed with a tripalmitin diet showed a depletion of phos pholipid arachidonate and n-3 fatty acids such as eicosapentaenoic and docosahexaenoic acids (EPA and DHA). In rats fed fish oil diet, a sig nificant reduction in arachidonic acid (AA) content was observed where as EPA and DHA were incorporated into membranes lipids. These changes in lipid composition of membranes did not affect cellular adherence, p hagocytic capability, or [H-3]AA incorporation. However, both tripalmi tin and fish oil diets induced a decrease in [H-3]AA mobilization stim ulated by 4 beta-phorbol-12-myristate 13-acetate, A23187, or opsonized -zymosan in rat peritoneal macrophages. These results demonstrate that the antiinflammatory effects of essential fatty acids deficiency or n -3 enrichment diets may be associated with a decreased AA mobilization in resident rat peritoneal macrophages treated with proinflammatory a gents.