| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Original Research Communications |
Background: Although medium-chain triacylglycerols (MCTs) may be utilized more efficiently than long-chain triacylglycerols (LCTs), their effect on protein metabolism remains controversial.
Objective: The aim of the study was to compare the effects of mixed MCT-LCT and pure LCT emulsions on leucine metabolism in preterm infants.
Design: Fourteen preterm [gestational age: 30 ± 1 wk; birth weight: 1409 ± 78 g (
± SE)] neonates were randomly assigned to receive, from the first day of life, either a 50:50 MCT-LCT (mixed MCT group; n = 7) or an LCT (LCT group; n = 7) lipid emulsion as part of an isonitrogenous, isoenergetic total parenteral nutrition program. On the fourth day, infants received intravenous feeding providing 3 g lipid, 15 g glucose, and 3 g amino acids
kg-1d-1 and underwent 1) indirect calorimetry and 2) a primed, 2-h infusion of H13CO3Na to assess the recovery of 13C in breath, immediately followed by 3) a 3-h infusion of L-[1-13C]leucine.
Results: The respiratory quotient tended to be slightly but not significantly higher in the mixed MCT than in the LCT group (0.96 ± 0.06 compared with 0.93 ± 0.03). We did not detect a significant difference between the mixed MCT and LCT groups with regard to release of leucine from protein breakdown (B; 309 ± 40 compared with 257 ± 46 µmolkg-1h-1) and nonoxidative leucine disposal (NOLD; 296 ± 36 compared with 285 ± 49 µmolkg-1h-1). In contrast, leucine oxidation was greater in the mixed MCT than in the LCT group (113 ± 10 compared with 67 ± 10 µmolkg-1h-1; P = 0.007). Net leucine balance (NOLD - B) was less positive in the mixed MCT than in the LCT group (-14 ± 9 compared with 28 ± 10 µmolkg-1h-1; P = 0.011).
Conclusion: Mixed MCTs may not be as effective as LCT-containing emulsions in promoting protein accretion in parenterally fed preterm neonates.
Key Words: Parenteral nutrition • protein metabolism • preterm infants • [13C]leucine • [13C]bicarbonate • lipid emulsions • stable isotopes • energy substrates • medium-chain triacylglycerols • long-chain triacylglycerols
This article has been cited by other articles:
|
|
 |
|
  D. Darmaun, V. Hayes, D. Schaeffer, S. Welch, and N. Mauras Effects of Glutamine and Recombinant Human Growth Hormone on Protein Metabolism in Prepubertal Children with Cystic Fibrosis J. Clin. Endocrinol. Metab., March 1, 2004; 89(3): 1146 - 1152. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. M. Wolf, N. Draghi, X. Liang, C. Dai, L. Uhrbom, C. Eklof, B. Westermark, E. C. Holland, and M. D. Resh p190RhoGAP can act to inhibit PDGF-induced gliomas in mice: a putative tumor suppressor encoded on human Chromosome 19q13.3 Genes & Dev., February 15, 2003; 17(4): 476 - 487. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Rodriguez, S. Funke, M. Fink, H. Demmelmair, M. Turini, G. Crozier, and B. Koletzko Plasma fatty acids and [13C]linoleic acid metabolism in preterm infants fed a formula with medium-chain triglycerides J. Lipid Res., January 1, 2003; 44(1): 41 - 48. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Humbert, L. Martin, H. Dumon, D. Darmaun, and P. Nguyen Dietary Protein Level Affects Protein Metabolism during the Postabsorptive State in Dogs J. Nutr., June 1, 2002; 132(6): 1676S - 1678. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
