n-3 Fatty Acids and Platelet-Vessel Wall Interactions

Abstract

The protective effects of n-3 fatty acids in vascular atherosclerotic diseases, as shown in a number of epidemiological and experimental studies, have led to the proposition that these compounds may interfere with platelet-vessel wall interactions, a process which is pivotal in the development of thrombosis and, possibly, of atherosclerosis. That n-3 fatty acids interfere with platelet-vessel wall interactions is simply demonstrated by the fact, now established beyond any reasonable doubt, that they are able to prolong the bleeding time. Bleeding time is a “global” test exploring platelet reactions to a standardized interruption of vascular integrity; actually it appears to be the only test practically available to explore these interactions in vivo, in humans, in an integrated way; it suffers however from methodological problems (some variability in technique) and from theoretical flaws: its relationship with actual bleeding in other parts of the body is not proven; its value — on the other hand — as a thrombotic predictor is also unproven; finally, because of its “globality”, it does not provide insights into the mechanism(s) involved in its alterations. Therefore a “dissection” of the effects of n-3 fatty acids on platelet-vessel wall interactions requires the analysis of:

• 1. studies on isolated platelets;

• 2. studies on the isolated vessel wall;

• 3. studies of interaction products.