Modulation of prostaglandin synthesis in mouse peritoneal macrophages by enrichment of lipids with either eicosapentaenoic or docosahexaenoic acids in vitro.

The n-3 polyunsaturated fatty acids (PUFA) of fish oils alter arachidonic acid (AA) metabolism in macrophages. The present investigation studied the efficacy of eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), two n-3 PUFA of fish, to alter lipid composition and specific functions of mouse peritoneal macrophages. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were readily incorporated by macrophages in vitro and replaced 25-50% of AA in cellular lipids. The EPA- or DHA-enriched cells synthesized significantly less (50-65%) prostaglandin E2 (PGE2), thromboxane B2 (TXB2) and 6 keto prostaglandin F1(1) alpha (6 keto PGF1 alpha) when stimulated with opsonized zymosan. The enrichment with EPA or DHA did not affect phagocytosis nor superoxide anion formation in macrophages. These studies demonstrated that EPA or DHA can be used to decrease prostaglandin synthesis selectively without affecting the other physiological functions of macrophages.