Alterations in the lipids and prostaglandins in mouse spleen following and ingestion of menhaden oil

Two groups of male mice were fed for 2 weeks with a semisynthetic diet supplemented with either 10% hydrogenated coconut oil or 10% menhaden oil. The spleen from animals fed with menhaden oil contained significantly higher amounts of polyunsaturated n-3 fatty acids. The n-3 fatty acids reciprocally replaced arachidonic acid in the phospholipids. The synthesis of 6-keto prostaglandin F1α and prostaglandin E₂ by spleen tissues were significantly depressed (70-80%) in mice consuming menhaden oil. These studies indicated that n-3 fatty acids can effectively displace arachidonic acid from spleen lipids and thereby affect the synthesis of prostaglandins. The implications of these observations are discussed.