Human Endogenous Plasma Lipemia Clearing Activity After Intravenous Fat Emulsions (Lipomul)

¹ From the Division of Laboratories and the Department of Medicine, Cedars of Lebanon Hospital, Los Angeles, California

Endogenous plasma lipemia clearing activity (lipoprotein lipase) has been evaluated in 10 individuals before and after intravenous fat. Blood was obtained in the postabsorptive state, after 15 minutes and 1 hour of the fat administration, and 1 hour after it was discontinued. Lipemia clearing activity was evaluated by determining the decrease in optical density upon in vitro incubation of plasma plus a coconut oil substrate. The inhibition characteristics of the clearing factor were identical with those of postheparin lipoprotein lipase. Lipemia clearing activity was both increased and decreased after the intravenous administration of the fat emulsion. The level of lipemia clearing activity which can be demonstrated in vitro is the resultant of its stimulation by fat intake and its inactivation by the clearing process itself.