Majority of dietary glutamine is utilized in first pass in preterm infants.
Glutamine is a conditionally essential amino acid for very low-birth weight infants by virtue of its ability to play an important role in several key metabolic processes of immune cells and enterocytes. Although glutamine is known to be used to a great extent, the exact splanchnic metabolism in enterally fed preterm infants is unknown. We hypothesized that preterm infants show a high splanchnic first-pass glutamine metabolism and the primary metabolic fate of glutamine is oxidation. Five preterm infants (mean + or - SD birth weight 1.07 + or - 0.22 kg and GA 29 + or - 2 wk) were studied by dual tracer ([U-(13)C]glutamine and [(15)N(2)]glutamine) cross-over techniques on two study days (at postnatal week 3 + or - 1 wk). Splanchnic and whole-body glutamine kinetics were assessed by plasma isotopic enrichment of [U-(13)C]glutamine and [(15)N(2)]glutamine and breath (13)CO(2) enrichments. Mean fractional first-pass glutamine uptake was 73 + or - 6% and 57 + or - 17% on the study days. The splanchnic tissues contributed for a large part (57 + or - 6%) to the total amount of labeled carbon from glutamine retrieved in expiratory air. Dietary glutamine is used to a great extent by the splanchnic tissues in preterm infants and its carbon skeleton has an important role as fuel source.
van der Schoor
Sophie R D
SR
Department of Pediatrics, VU University Medical Center, Amsterdam 1081 HV, The Netherlands. s.vanderschoor@vumc.nl
Schierbeek
Henk
H
Bet
Pierre M
PM
Vermeulen
Marijn J
MJ
Lafeber
Harrie N
HN
van Goudoever
Johannes B
JB
van Elburg
Ruurd M
RM
D001944:Breath Tests; D002245:Carbon Dioxide / Q000378:metabolism; D002247:Carbon Isotopes; D018592:Cross-Over Studies; D004032:Diet; D004734:Energy Metabolism; D004750:Enteral Nutrition; D045853:Exhalation; D005973:Glutamine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D010084:Oxidation-Reduction; D013152:Splanchnic Circulation
D002247:Carbon Isotopes; D005973:Glutamine; D002245:Carbon Dioxide