Dietary source of omega-3 fatty acids affects endotoxin-induced peritoneal macrophage tumor necrosis factor and eicosanoid synthesis.

The effect of 8 weeks of feeding diets enriched with corn oil, linseed oil, or menhaden oil on endotoxin- and calcium ionophore (A23187)-induced tumor necrosis factor (TNF) and eicosanoid synthesis by rat peritoneal macrophages was determined. The fatty acid composition of macrophage phospholipids and TNF activity and eicosanoid synthesis in response to endotoxin and A23187 were determined. The ratio of omega-6/omega-3 fatty acids in macrophages from linseed oil or menhaden oil-fed rats decreased approximately 24- and 55-fold, respectively. Basal and endotoxin-induced synthesis of TNF was increased by ingestion of the menhaden oil diet but not by the linseed oil diet. Ingestion of the menhaden oil and linseed oil diets significantly reduced basal, endotoxin-, and A23187-induced synthesis of eicosanoids compared with the corn oil group. Ingestion of the menhaden oil diet resulted in a greater decrease in eicosanoid synthesis than the linseed oil diet.