Modulation of avian lung eicosanoids by dietary omega-3 fatty acids

This study was conducted to determine if dietary omega-3 polyunsaturated fatty acids could modulate lung eicosanoid production. Three groups of chickens were depleted of essential fatty acids by feeding diets containing 1% hydrogenated coconut oil from hatching to 8 wk, followed by repletion for 3 wk with diets containing soybean oil (SBO) and linseed oil (LSO) separately or in combination. The ratio of linoleic acid (18:2 omega 6) to linolenic acid (18:3 omega 3) was 7.48, 1.17 or 0.32, respectively, for diets containing 10% SBO, 5% SBO/5% LSO or 10% LSO. A 10% SBO diet fed for 11 wk served as the control. Production of prostaglandin F2 alpha, prostaglandin E, thromboxane B2 and 6-keto-prostaglandin F1 alpha by incubated lung was lower in birds fed linseed oil, with total prostanoid production being 95, 42 and 22% of control values for the three dietary treatments, respectively. The ratio of arachidonic acid (20:4 omega 6) to linoleic acid (18:2 omega 6) in serum phospholipids followed a similar pattern for the three treatments, with values of 0.96, 0.52 and 0.21. Thus, production of lung prostanoids of the 2-series could be modulated by varying the dietary omega 6/omega 3 ratio. This effect may be due in part to depression of phospholipid arachidonate, the precursor of 2-series eicosanoids.