Changes in serum lipoproteins in humans following the infusion of a fat emulsion containing medium- and long-chain triglycerides

Abstract. A fat emulsion containing equal parts of medium-chain triglycerides (MCT) and long-chain triglycerides (LCT) and emulsified with egg phospholipids (Lipofundin MCT 10%®) was compared with LCT emulsions (Intralipid 10%®, egg phospholipids; Lipofundin S 10%®, soya phospholipids) in six volunteers, using 4-h periods of infusion and doses of 0·15 g kg^-1 body h^-1. At the end of infusion very low density lipoprotein (VLDL) triglyceride concentrations were highest with Intralipid, marginally less with Lipofundin MCT and lowest with Lipofundin S. With Lipofundin MCT infusion the proportions of free mediumchain fatty acids in serum reached 30%. In VLDL the ratios triglycerides/apolipoprotein B and triglycerides/phospholipids rose most after Lipofundin MCT and least after Lipofundin S. With Lipofundin MCT and Intralipid, surface components in low density lipoproteins (LDL) are lessened in relation to the internal components; this does not occur with Lipofundin S. High density lipoprotein (HDL) subfractions are influenced in identical directions by all fat emulsions with exception of a single increase of phospholipids in (HDL₃) after Lipofundin MCT.