The effects of dietary n-3 vs. n-6 fatty acids on ex-vivo LTB₄ generation by canine neutrophils

Dietary n-3 polyunsaturated fatty acids are widely used for amelioration of inflammatory skin disease in dogs. In this study, a diet containing two different sources of n-3 polyunsaturated fatty acid-triglyceride (from menhaden oil) and concentrated ethyl esters-was fed to one group of six purpose-bred dogs, while an isocaloric isonitrogenous diet with corn oil (n-6 polyunsaturated fatty acids) was fed to another group of eight purpose-bred dogs for six weeks. Peripheral blood neutrophils, isolated at week-1 (baseline), week 2 and week 6, were stimulated with calcium ionophore A23187 and the amount of leukotriene B₄ produced was determined via reversed-phase high performance liquid chromatography. Analysis of variance of log-transformed data revealed a significant effect for diet (P = 0.005) at six weeks, with dogs fed the high n-3 polyunsaturated fatty acid diet having significantly less mean ex vivo neutrophil leukotriene B₄ production than dogs fed the high n-6 polyunsaturated fatty acid diet. Further studies on the clinical usefulness of n-3 polyunsaturated fatty acid ethyl esters are warranted.