Dietary ω3 polyunsaturated fatty acids augment endothelium-dependent relaxation to bradykinin in coronary microvessels of the pig

Abstract

The effects of chronic dietary supplementation with ω3 polyunsaturated fatty acids on endothelium-dependent relaxations were examined in isolated coronary microvessels of the pig. Animals were maintained for four weeks with or without dietary supplementation of purified eicosapentaenoic acid (3.5 g daily) and docosahexaenoic acid (1.5 g daily). Fatty acid profiles of plasma lipids showed that only the fraction of eicosapentaenoic acid increased by the treatment, together with a decrease of that of arachidonic acid. In the treated group, endothelium-dependent relaxations to bradykinin were significantly augmented, while contractions to acetylcholine or relaxations to nitroprusside were unaltered. These results indicate that dietary ω3 polyunsaturated fatty acids (mainly eicosapentaenoic acid) augment endothelium-dependent relaxations in coronary microvessels of the pig, without changing the ability of vascular smooth muscle to contract or relax.