Dietary fish oil reduces microvascular thrombosis in a porcine experimental model

Microvascular thrombosis plays a significant role in the pathophysiology of ischaemic reperfusion injury. A fish oil-supplemented diet containing n-3 polyunsaturated fatty acids (PUFA) reduces thromboxane A(2) (TxA(2)) synthe sis and, thus, vasoconstriction and platelet aggregation. The aim of this s tudy was to elucidate whether n-3 PUFA in a porcine model of ischaemia and reperfusion injury 1) inhibit accumulation of platelets and fibrinogen in i schaemia-reperfusion injured tissue, 2) prolong the bleeding time, and 3) i nhibit TxA(2) synthesis. Nine pigs were fed a standard diet supplemented wi th 7 g n-3 PUFA/day for 3 weeks. Nine pigs on the standard diet served as c ontrols. Unilateral myocutaneous flaps were exposed to ischaemia for a peri od of 6 hours. Contralateral flaps were nonischaemic. Tissue contents of ra dioactive-labelled platelets and fibrinogen were measured after 4 hours of reperfusion. Platelet count, serum TxB(2), and the cutaneous bleeding time were measured before and after 3 weeks of diet. In the fish oil group, the accumulation of platelets was significantly reduced in all the myocutaneous flaps, except In the ischaemic skin part, when compared to control animals . Fibrinogen was significantly reduced in nonischaemic flaps, but not in is chaemic flaps. After the feeding period, the level of TxB(2) was significan tly lowered in the fish oil group (p<0.01). No difference in the bleeding t ime was observed. Thus, dietary supplementation with n-3 PUFA inhibits the formation of microvasculatory thrombosis in this model. (C) 2000 Elsevier S cience Ltd. All rights reserved.