Changes in blood coagulation during the clearing of lipid emulsions by lipoprotein lipase.

The clearing of lipid emulsions by postheparin plasma from rabbits or human beings was accompanied regularly by a sharp reduction in the recalcification time of the plasma. No change in blood coagulation took place when the activity of lipoprotein lipase, the clearing enzyme, was inhibited by means of heat or the action of a surface-active agent. In control studies, the recalcification time of postheparin plasma was not altered by the addition of glycerol, free fatty acids, or the products of hydrolysis of a lipid emulsion. Taken together, the findings indicated that a heat-labile factor was released during the course of clearing which was capable of inactivating reversibly the anti-coagulant properties of heparin.