Inclusion of 10% fish oil in mixed medium-chain triacylglycerol-long-chain triacylglycerol emulsions increases plasma triacylglycerol clearance and induces rapid eicosapentaenoic acid (20:5n-3) incorporation into blood cell phospholipids.
BACKGROUND
Lipolysis of a fish oil (FO) emulsion is much slower than that of a soybean [long-chain triacylglycerol (LCT)] emulsion; in contrast, emulsions containing medium-chain triacylglycerol (MCT) are efficiently hydrolyzed by lipoprotein lipase.


OBJECTIVE
We questioned whether incorporating 10% FO in a mixed MCT-LCT emulsion would affect plasma triacylglycerol clearance and provide efficient delivery of n-3 polyunsaturated fatty acids to cells and tissues.


METHODS
This prospective crossover study was conducted in 8 normolipidemic subjects with the use of the hypertriglyceridemic clamp model and compared plasma triacylglycerol clearance of a lipid emulsion (5:4:1) made of 50% MCT, 40% LCT, and 10% FO (wt:wt:wt) to a control (5:5) preparation with 50% MCT and 50% LCT. Subjects were daily infused for 5 h, over 4 consecutive days. Fatty acyl pattern was daily measured in plasma phospholipids as well as in leukocyte and platelet phospholipids.


RESULTS
Inclusion of 10% FO in mixed emulsion particles enhanced plasma clearance of infused triacylglycerols (18%; P < 0.0001). The faster elimination of the 5:4:1 emulsion appears related to an enhanced uptake of remnant particles rather than to faster intravascular lipolysis. Each infusion of 5:4:1 raised the eicosapentaenoic acid (C20:5n-3) concentration in blood cell phospholipids to reach a 7-fold enrichment in platelets and a >2-fold enrichment in leukocytes after 4 infusions. In contrast, the docosahexaenoic acid (C22:6n-3) concentration remained unchanged in blood cell phospholipids.


CONCLUSIONS
Infusion of a mixed emulsion with MCTs, soy LCTs, and FO is associated with efficient plasma triacylglycerol clearance and results in rapid incorporation of C20:5n-3 but not C22:6n-3 in leukocyte and platelet phospholipids.
Simoens
Christian M
CM
L Deloyers Laboratory for Experimental Surgery, Université Libre de Bruxelles, Brussels, Belgium and the Intensive Care Unit, CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium.
Deckelbaum
Richard J
RJ
Massaut
Jacques J
JJ
Carpentier
Yvon A
YA
D000328:Adult; D001792:Blood Platelets / Q000737:chemistry / Q000378:metabolism; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D015118:Eicosapentaenoic Acid / Q000378:metabolism*; D005217:Fat Emulsions, Intravenous / Q000737:chemistry; D005395:Fish Oils / Q000008:administration & dosage*; D006801:Humans; D007962:Leukocytes / Q000737:chemistry / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D008657:Metabolic Clearance Rate; D010288:Parenteral Nutrition; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism*; D011446:Prospective Studies; D014280:Triglycerides / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*
D005217:Fat Emulsions, Intravenous; D005395:Fish Oils; D010743:Phospholipids; D014280:Triglycerides; D015118:Eicosapentaenoic Acid