Hypercoagulability induced by hyperlipemia in rat, rabbit and man. Role of platelet factor 3.

Feeding a butter-rich diet to rats induced a "hypercoagulable state," since multiple large thrombi were observed in response to injection of S. typhosa endotoxin but the same stimulus was ineffective in rats fed a corn oil-rich diet or laboratory chow. In vitro hypercoagulability was noted in blood from the butter-fed rats, the recalcification plasma clotting time (PCT) being reduced by 34 to 45% in comparison with the controls. When a phospholipid suspension replaced the platelets in the plasma clotting test, the reduction was only 5 to 15%, but it was 31 and 43% when the platelets of these rats were washed and resuspended in a given standard plasma. Since lipid extract of these platelets could largely reproduce their activity, the factor involved must have been factor 3. A similar result was obtained in rabbits fed a butter or corn oil diet, or laboratory chow, indicating that, in this species also, the hypercoagulability in response to hyperlipemia was largely due to factor 3. In addition, in rats and rabbits fed butter, the platelets were more susceptible to thrombin-induced aggregation. In 27 human subjects of either sex and various ages, the state of coagulability as determined by the PCT was also mostly related to the platelet factor 3 activity, which was negatively correlated with serum cholesterol. ADDITIONAL