Effect of dietary oils on the production of n-3 and n-6 metabolites of leukocyte 5-lipoxygenase in five rat strains.

Abstract We examined the influence of various dietary oils, including linseed and fish oil on the relative rates of leukotriene B 4 (LTB 4 ) and LTB 5 production by rat peritoneal exudate cells in five rat strains. While there was an association between the membrane phospholipid levels of the fatty acid precursors (arachidonic acid (AA) and eicosapentaenoic acid (EPA)) and the rate of synthesis of their respective 5-lipoxygenase products (LTB 4 and LTB 5 ), the rate of LTB 4 synthesis was a combined function of both AA and EPA levels. We observed a strong linear relationship (correlation coefficient = 0.99) between the ratio of EPA/AA in the cell membrane phospholipids and the ratio of LTB 5 /LTB 4 produced by these cells in vitro; this association was independent of genetic (strain) variability and was independent of the source of EPA (dietary EPA or EPA endogenously synthesized from dietary α-linolenic acid).