EVIDENCE FOR THE MECHANISM BY WHICH EICOSAPENTAENOIC ACID INHIBITS HUMAN-PLATELET AGGREGATION AND SECRETION - IMPLICATIONS FOR THE PREVENTION OF VASCULAR-DISEASE

The effects of eicosapentaenoic acid (EPA) on human platelet aggregation and secretion were assessed. EPA was found to partially inhibit the first phase of ADP induced aggregation, and completely abolished the second phase of aggregation and secretion. Similarly, inhibitory effects were obtained when aggregation and secretion were induced by collagen, adrenaline, thrombin, arachidonic acid and the ionophore A23187. Acetylsalicylic acid markedly reduced the inhibitory effects of EPA on aggregation induced by ADP and the endoperoxide analogue U46619. Rat arterial tissue, when incubated with EPA, produced a substance which inhibited collagen induced aggregation and also elevated the level of cyclic AMP in platelets which may explain its inhibitory effect. It is suggested that the enzyme cyclo-oxygenase converts EPA to substances which inhibit platelet aggregation and secretion. © 1979.