Clearing factor lipase (lipoprotein lipase) activator. A method for the measurement of the net activating ability of human sera.

The hydrolysis of an emulsified triglyceride substrate by clearing factor lipase (lipoprotein lipase) normally requires the presence of particular activating polypeptide species. These are present in serum, together with other inhibitory species, as part of the serum lipoproteins. The paper describes a method whereby the net activating ability of individual human sera may be measured routinely. In a normal population, this activating ability is shown to be correlated positively with the fasting serum triglyceride concentration. As the fasting triglyceride concentration increases, there is a rise in the proportion of the total activating ability that is associated with the very low density lipoproteins. A dietary fat load does not raise the total activating ability but does increase the proportion of the total that is associated with the serum lipoproteins of lowest density.