Plasma F 2α-isoprostane levels are lowered in pigs fed an (n-3) polyunsaturated fatty acid supplemented diet following occlusion of the left anterior descending coronary artery

Abstract

F 2α-isoprostanes, produced non-enzymatically from arachidonic acid are potent vasoconstrictors. Dietary supplementation with (n-3) polyunsaturated fatty acids has been shown to reduce arachidonic acid levels in the body. In the present study, alterations in plasma levels of the F 2α-isoprostane, 8-iso-prostaglandin F 2α, were assessed by enzyme immunoassay in pigs following (n-3) polyunsaturated fatty acid supplementation and during occlusion of the left anterior descending coronary artery. Pigs were fed diets supplemented with either fish oil (rich in n-3 polyunsaturated fatty acids) or beef tallow (high content of saturated fatty acids) for a 6 week period. The animals were then anesthetised and plasma samples were collected. The coronary artery was occluded and the blood samples were collected during the following 10 minutes. While plasma 8-iso-prostaglandin F 2α levels were generally lower in pigs fed the (n-3) fatty acid supplemented diet as compared with those fed the diet high in saturated fats, this response only reached statistical significance (P<0.05) during the 10 minute period of coronary occlusion. Notwithstanding this, plasma 8-iso-prostaglandin F 2α remained unchanged in both dietary groups once occlusion was initiated. Significant differences (P<0.05) in the fatty acid profile of blood plasma were detected between the two dietary groups, but occlusion failed to alter these parameters. The results demonstrate that (n-3) polyunsaturated fatty acid dietary supplementation lowers 8-iso-prostaglandin F 2α levels in the porcine circulation in comparison with animals fed beef tallow, particularly after coronary occlusion. This effect compliments the well established action of (n-3) fatty acids in reducing the production of vasoconstrictive eicosanoids.