title: In vivo and in vitro properties of an intravenous lipid emulsion containing only medium chain and fish oil triglycerides.
abstract: OBJECTIVE
  The triglyceride (TG) fatty acyl composition in lipid emulsions influences their metabolism. Little is known about the effects of long chain omega-3 polyunsaturated fatty acids (PUFA) on lipid emulsion metabolism. We investigated possible differences between omega-3 containing emulsions in their metabolism and tissue-targeting in vivo in a mouse model, and in vitro using lipolysis and cell culture experiments.
  
  
  METHODS
  Soy oil (LCT), MCT/LCT/omega-3 (5:4:1, wt/wt/wt), and MCT/omega-3 (8:2, wt/wt) emulsions were radiolabeled with nondegradable 1alpha,2alpha (n)-[3H] cholesteryl oleoyl ether to trace core particle metabolism in C57BL/6J mice following a bolus injection. Blood samples obtained over 25 min and extracted organs were used to measure the tissue distribution of lipid emulsion particles. Lipoprotein lipase (LpL)-mediated hydrolysis experiments and cell uptake studies in cultured J774 murine macrophages were also performed.
  
  
  RESULTS
  Blood clearance of 8:2 was 13.4% and 29.8% faster compared to 5:4:1 and LCT, respectively. LCT had greatest liver uptake. LpL-mediated hydrolysis was greatest in 8:2 and lowest in LCT. Overall, cell TG accumulation in the presence of apolipoprotein E was least with 8:2.
  
  
  CONCLUSIONS
  Our data shows that 8:2 had the most efficient blood clearance but less hepatic uptake in vivo. In vitro, 8:2 had both highest hydrolysis by LpL and intracellular TG utilization in the presence of apoE. Thus, an 8:2 lipid emulsion undergoes efficient blood clearance and may direct omega-3 PUFA more towards extrahepatic tissues.
authors.affiliation: Division of Gastroenterology, Hepatology, & Nutrition, Department of Pediatrics, Columbia University Medical Center, New York, NY, USA.
authors.forename: Mimi N
authors.initials: MN
authors.lastname: Ton
authors.forename: Chuchun
authors.initials: C
authors.lastname: Chang
authors.forename: Yvon A
authors.initials: YA
authors.lastname: Carpentier
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Deckelbaum
mesh_terms: D000818:Animals; D001057:Apolipoproteins E / Q000378:metabolism / Q000494:pharmacology; D005217:Fat Emulsions, Intravenous / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage*; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism; D008657:Metabolic Clearance Rate; D051379:Mice; D008810:Mice, Inbred C57BL; D011897:Random Allocation; D014018:Tissue Distribution; D014280:Triglycerides / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001057:Apolipoproteins E; D005217:Fat Emulsions, Intravenous; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D014280:Triglycerides