Fish oil inhibits photochemically induced thrombosis in the guinea pig in a dose dependent manner.

The dose-response effect of dietary fish oil was investigated in the photochemically induced thrombosis model in guinea pigs. In this arterial thrombosis model thrombus formation was evaluated by determination of different occlusion parameters (percentage of occlusion, area under the blood flow curve, time to first occlusion, spontaneous reflow). Sixty guinea pigs (7 weeks old) were randomly assigned to and fed a 40 energy % diet containing increasing amounts (0, 5.5, 17 and 36 energy %) of fish oil for four weeks. Arterial thrombosis was induced in the femoral artery by free radical damage and subsequent thrombus formation. Increasing fish oil concentrations in the diet were associated with a linear decrease (p<0.001) in the percentage of occlusion (calculated as a decrease in blood flow) and a linear increase in area under the blood flow curve/begin flow (p<0.001). The time to thrombus formation was not significantly prolonged in any group. However the frequency of animals in which complete occlusion of the femoral artery was not obtained during the thrombosis induction and subsequent observation period was higher in the groups receiving the two highest doses of fish oil. Spontaneous reflow correlated positively (p<0.013) with increasing dietary fish oil content. In conclusion, our data indicates that dietary fish oil inhibits photochemically induced thrombosis in this animal model of arterial thrombosis in a dose dependent manner.