Plasma Fibrinolysis in Man: the Effect of Chylomicrons Derived from Different Dietary Fats

The plasma fibrinolytic activity, measured in vitro, of 17 healthy normal young males was consistently and equally inhibited by prior ingestion of equal amounts of either a relatively saturated animal fat (butterfat) or a highly unsaturated vegetable fat (safflower oil). This effect was further studied by the addition of purified chylomicrons derived from ingestion of either butterfat, safflower oil, or egg yolk to an in vitro system. The inhibitory effect was quantitatively similar in all experiments despite wide variations in composition of the fed fat and pronounced differences in fatty acid composition of the lipids of the chylomicrons. It seems reasonable to suggest from our data that the proteins and the nonfatty acid portions of the chylomicron phospholipids may be important determinants of the inhibitory effect of chylomicrons on fibrinolysis.