Docosahexaenoic acid (22:6n3)-induced relaxation of the rat aorta.

Dietary consumption of fish and fish oil supplements, containing eicosapentaenoic acid and docosahexaenoic acid, has been associated with favorable alterations in the cardiovascular system, such as, a reduction in blood pressure. Therefore, the effects of docosahexaenoic acid (22:6n3) on isometric tension of rat aortic smooth muscle were investigated. A concentration-dependent (1-127 microM) relaxation (6-30%) was induced by 22:6n3 in non-precontracted vessels. Docosaehexaenoic acid, concentration dependently (1-44 microM) reversed contractions of rat aortic rings induced by phenylephrine (7-43%) and by U44069 (8-52%). These results indicate that the relaxant effects produced by 22:6n3 in the rat aorta are concentration-dependent and not specific to the contractile agonist.