Effect of intravenous lipid emulsions on hepatic cholesterol metabolism

Background: Total parenteral nutrition offers the chance of survival to chi ldren who have had extensive gut resections or gut failure. However, in inf ants it is often associated with serious complications including cholestati c liver disease. The causes of these complications remain unclear, although it has been suggested that the lipid emulsions used in total parenteral nu trition may be responsible. Methods: An in vitro system was developed to study the effect of lipid emul sions on hepatic cholesterol metabolism using cultured hepatocytes. Results: Incubations of Hep G2 cells with medium containing Intralipid (Pha rmacia and Upjohn, Milton Keynes, UK) demonstrated that the fat emulsion me diated a powerful dose-dependent but reversible inhibition of cholesterol u ptake. In addition Intralipid was shown to stimulate the efflux of choleste rol from Hep G2. cells. The component or components of the Intralipid respo nsible for these effects and the mechanism by which they act remain to be e stablished. Conclusions: Intravenous lipid emulsions may interfere with hepatic cholest erol metabolism in vivo. This may have implications for the development of total parenteral nutrition-associated cholestasis in neonates. (C) 2000 Lip pincott Williams & Wilkins, Inc.