Medium-chain Compared With Long-Chain Triacylglycerol Emulsions Enhance Macrophage Response and Increase Mucosal Mass in Parenterally Fed Rats

Am J Clin Nutr. 1998 Jun;67(6):1265-72. doi: 10.1093/ajcn/67.6.1265.


We tested whether infusion of medium-chain triacylglycerols (MCTs) during total parenteral nutrition (TPN) enhanced macrophage response and reduced intestinal atrophy compared with long-chain triacylglycerols (LCTs). Male Sprague-Dawley rats (230-240 g) were maintained with TPN providing 16% or 48% of nonprotein energy from MCTs plus LCTs or LCTs alone or 100% of nonprotein energy from dextrose for 6 or 12 d. Body weight gain was not significantly different among groups. Serum concentrations of beta-hydroxybutyrate were greater with MCTs plus LCTs than with LCTs alone after 6 d (P < 0.05, main effect). Triacylglycerol concentrations in liver were greater with LCTs than with MCTs plus LCTs after 6 or 12 d (P < 0.05, main effect). MCTs plus LCTs increased by 50% the percentage (P < 0.0005) and number of splenic macrophages compared with LCTs alone in conjunction with decreased triacylglycerol concentrations in spleen after 6 d (P < 0.05, main effect). In vitro tumor necrosis factor alpha secretion by splenic or circulating macrophages in response to lipopolysaccharide was increased by MCTs plus LCTs compared with LCTs alone, twofold after 6 and sevenfold after 12 d (P < 0.05, main effect). Jejunal mucosal mass was 30% greater with MCTs plus LCTs than with LCTs alone after 6 or 12 d (P < 0.01); villus height was also significantly greater after 6 d (main effect). The incidence of bacterial translocation to the mesenteric lymph nodes was not significantly different among groups. Compared with LCTs, MCTs enhanced macrophage response and decreased intestinal atrophy.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Bacterial Translocation / drug effects
  • Emulsions
  • Intestinal Mucosa / drug effects*
  • Intestinal Mucosa / immunology
  • Intestinal Mucosa / pathology
  • Liver / metabolism
  • Macrophages / drug effects*
  • Male
  • Parenteral Nutrition, Total*
  • Rats
  • Rats, Sprague-Dawley
  • Spleen / metabolism
  • Triglycerides / administration & dosage
  • Triglycerides / metabolism
  • Triglycerides / pharmacology*
  • Tumor Necrosis Factor-alpha / biosynthesis


  • Emulsions
  • Triglycerides
  • Tumor Necrosis Factor-alpha