EFFECT OF DIETARY DOCOSAHEXAENOIC ACID SUPPLEMENTATION ON PLATELET-FUNCTION - STUDIES IN THE RAT FEMORAL-ARTERY THROMBOSIS MODEL

We have developed a model whereby the femoral artery in an experimental animal can be occluded by a photochemical reaction between rose bengal and green light which causes endothelial injury followed by platelet adhesion, aggregation and formation of a platelet rich thrombus at the site of the reaction. Using this model, we investigated the effect of dietary docosahexaenoic acid (DHA) supplementation on platelet aggregation and on serum cholesterol and lipids. Male Wistar rats (6-weeks-old) received dietary DHA supplementation (300 mg/kg/d) for 8 weeks. This regimen produced a significant (p < 0.05) decrease in serum free-cholesterol and phospholipids levels, inhibited platelet aggregation ex vivo induced by collagen in whole blood (p < 0.05) but not in platelet rich plasma, reduced thromboxane B2 formation (p < 0.01) induced by collagen in washed platelets and prolonged the time for thrombotic arterial occlusion (p < 0.01) as compared with values obtained in animals on standard diet. In conclusion, dietary DHA produces antithrombotic effects such as reduction in platelet aggregability and lowering of plasma cholesterol. Whole blood where red and white blood cells can exert their influences on platelet function is a more sensitive and physiological medium than platelet rich plasma for studying the effects of antithrombotic treatments on platelet aggregability ex vivo.