Post-heparin Lipolytic Activity and Blood Platelets

Abstract

THERE have been several reports indicating a possible interrelationship between plasma lipoprotein lipase activity and blood platelets. Mitchell¹ and Gardikas et al.², using changes in the optical density of plasma as indicators of lipolytic activity, have reported an inhibition of lipoprotein lipase activity by platelets. The presence of platelets contributes materially to plasma turbidity, however, and the changes in optical density, particularly proportionate changes, may not be an accurate measure of lipase activity. Hollett and Nestel³ have shown that the clearing activity after administration of heparin, as measured by changes in optical density, and lipolytic activity, as determined by glycerol production, do not necessarily parallel each other. More recent results indicate that the lipoprotein lipase activity and “stickiness” of blood platelets are both altered in human cardiovascular disease⁴. We therefore decided to reinvestigate the relationship between lipoprotein lipase and blood platelets using heparin as an inducer and the release of free fatty acids (FFA) as a measure of the lipolytic activity.