THE EFFECTS OF PURIFIED EICOSAPENTAENOIC AND DOCOSAHEXAENOIC ACIDS ONARTERIAL THROMBOSIS TENDENCY AND PLATELET-FUNCTION IN RATS

Dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) wer e compared for their effects on arterial thrombus formation in vivo us ing a well validated rat model. Platelet aggregation (triggered by col lagen or adenosine diphosphate in whole hirudinized blood), thromboxan e formation (TxB(2)) and platelet phospholipid fatty acid composition were measured also. Animals fed diets containing hydrogenated coconut oil or sunflower seed oil served as prothrombotic and antithrombotic c ontrols, respectively. In a first study, rats were fed a mixture of EP A and DHA ethyl esters (MIX) in increasing amounts and results indicat ed that 4% of n-3 fatty acids had an optimum reducing effect on thromb osis tendency. Dietary administration of MIX further resulted in a dos e-dependent promotion of disaggregation after collagen-induced aggrega tion, which significantly correlated with the reduction in platelet Tx B(2) formation. In a subsequent comparative study, both EPA and DHA et hyl esters affected thrombosis tendency, platelet aggregation and TxB( 2) formation to a similar extent. In addition, both polyenes increased the apparent thromboxane A(2)-sensitivity of platelets, which appeare d negatively related to arterial thrombosis tendency. We conclude that EPA and DHA have similar reducing effects on arterial thrombogenesis in vivo in rats and have comparable effects on the selected platelet f unctions in vitro. (C) 1998 Elsevier Science B.V.