Leucine kinetics during feeding in normal newborns

Scott Denne, Elena M. Rossi, Satish C. Kalhan

Research output: Contribution to journalArticle

56 Citations (Scopus)

Abstract

To examine how leucine and protein metabolism is affected by feeding, leucine kinetics were determined in 11 normal term newborns during feeding using a prime constant tracer infusion of 1-<sup>13</sup>C leucine combined with respiratory calorimetry. Fed newborns were compared with previously studied fasting newborns. Feeding and fasting newborns had similar rates of leucine oxidation (34 ± 3 μmol/kg/h versus 31 ± 4 μmol/kg/h) and leucine release from existing protein (156 ± 16 μmol/kg/h versus 164 ± 8 μnol/kg/h). In contrast, nonoxidative disposal rates of leucine (a reflection of protein synthesis) were significantly greater in feeding newborns (170 ± 13 μmol/kg/h versus 129 ± 9 μmol/kg/h). A significant positive correlation between birth weight and leucine flux was demonstrated in both feeding and fasting newborns. These results suggest that /) newborns may accomplish protein accretion primarily by increases in protein synthesis rather than suppression of protein breakdown; 2) an estimate can be made of the minimal leucine intake required to replace irreversible leucine oxidative losses (816 μmol/kg/d, 107 mg/kg/d); and 3) the positive correlation between birth weight and leucine flux in both feeding and fasting newborns may be a result of differences in previous protein and energy supplies.

Original languageEnglish
Pages (from-to)23-27
Number of pages5
JournalPediatric Research
Volume30
Issue number1
StatePublished - 1991

Fingerprint

Leucine
Fasting
Proteins
Birth Weight
Calorimetry

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health

Cite this

Denne, S., Rossi, E. M., & Kalhan, S. C. (1991). Leucine kinetics during feeding in normal newborns. Pediatric Research, 30(1), 23-27.

Leucine kinetics during feeding in normal newborns. / Denne, Scott; Rossi, Elena M.; Kalhan, Satish C.

In: Pediatric Research, Vol. 30, No. 1, 1991, p. 23-27.

Research output: Contribution to journalArticle

Denne, S, Rossi, EM & Kalhan, SC 1991, 'Leucine kinetics during feeding in normal newborns', Pediatric Research, vol. 30, no. 1, pp. 23-27.
Denne, Scott ; Rossi, Elena M. ; Kalhan, Satish C. / Leucine kinetics during feeding in normal newborns. In: Pediatric Research. 1991 ; Vol. 30, No. 1. pp. 23-27.
@article{d286890c33b844e680bfc3e7aa46de81,
title = "Leucine kinetics during feeding in normal newborns",
abstract = "To examine how leucine and protein metabolism is affected by feeding, leucine kinetics were determined in 11 normal term newborns during feeding using a prime constant tracer infusion of 1-13C leucine combined with respiratory calorimetry. Fed newborns were compared with previously studied fasting newborns. Feeding and fasting newborns had similar rates of leucine oxidation (34 ± 3 μmol/kg/h versus 31 ± 4 μmol/kg/h) and leucine release from existing protein (156 ± 16 μmol/kg/h versus 164 ± 8 μnol/kg/h). In contrast, nonoxidative disposal rates of leucine (a reflection of protein synthesis) were significantly greater in feeding newborns (170 ± 13 μmol/kg/h versus 129 ± 9 μmol/kg/h). A significant positive correlation between birth weight and leucine flux was demonstrated in both feeding and fasting newborns. These results suggest that /) newborns may accomplish protein accretion primarily by increases in protein synthesis rather than suppression of protein breakdown; 2) an estimate can be made of the minimal leucine intake required to replace irreversible leucine oxidative losses (816 μmol/kg/d, 107 mg/kg/d); and 3) the positive correlation between birth weight and leucine flux in both feeding and fasting newborns may be a result of differences in previous protein and energy supplies.",
author = "Scott Denne and Rossi, {Elena M.} and Kalhan, {Satish C.}",
year = "1991",
language = "English",
volume = "30",
pages = "23--27",
journal = "Pediatric Research",
issn = "0031-3998",
publisher = "Lippincott Williams and Wilkins",
number = "1",

}

TY - JOUR

T1 - Leucine kinetics during feeding in normal newborns

AU - Denne, Scott

AU - Rossi, Elena M.

AU - Kalhan, Satish C.

PY - 1991

Y1 - 1991

N2 - To examine how leucine and protein metabolism is affected by feeding, leucine kinetics were determined in 11 normal term newborns during feeding using a prime constant tracer infusion of 1-13C leucine combined with respiratory calorimetry. Fed newborns were compared with previously studied fasting newborns. Feeding and fasting newborns had similar rates of leucine oxidation (34 ± 3 μmol/kg/h versus 31 ± 4 μmol/kg/h) and leucine release from existing protein (156 ± 16 μmol/kg/h versus 164 ± 8 μnol/kg/h). In contrast, nonoxidative disposal rates of leucine (a reflection of protein synthesis) were significantly greater in feeding newborns (170 ± 13 μmol/kg/h versus 129 ± 9 μmol/kg/h). A significant positive correlation between birth weight and leucine flux was demonstrated in both feeding and fasting newborns. These results suggest that /) newborns may accomplish protein accretion primarily by increases in protein synthesis rather than suppression of protein breakdown; 2) an estimate can be made of the minimal leucine intake required to replace irreversible leucine oxidative losses (816 μmol/kg/d, 107 mg/kg/d); and 3) the positive correlation between birth weight and leucine flux in both feeding and fasting newborns may be a result of differences in previous protein and energy supplies.

AB - To examine how leucine and protein metabolism is affected by feeding, leucine kinetics were determined in 11 normal term newborns during feeding using a prime constant tracer infusion of 1-13C leucine combined with respiratory calorimetry. Fed newborns were compared with previously studied fasting newborns. Feeding and fasting newborns had similar rates of leucine oxidation (34 ± 3 μmol/kg/h versus 31 ± 4 μmol/kg/h) and leucine release from existing protein (156 ± 16 μmol/kg/h versus 164 ± 8 μnol/kg/h). In contrast, nonoxidative disposal rates of leucine (a reflection of protein synthesis) were significantly greater in feeding newborns (170 ± 13 μmol/kg/h versus 129 ± 9 μmol/kg/h). A significant positive correlation between birth weight and leucine flux was demonstrated in both feeding and fasting newborns. These results suggest that /) newborns may accomplish protein accretion primarily by increases in protein synthesis rather than suppression of protein breakdown; 2) an estimate can be made of the minimal leucine intake required to replace irreversible leucine oxidative losses (816 μmol/kg/d, 107 mg/kg/d); and 3) the positive correlation between birth weight and leucine flux in both feeding and fasting newborns may be a result of differences in previous protein and energy supplies.

UR - http://www.scopus.com/inward/record.url?scp=0025744609&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025744609&partnerID=8YFLogxK

M3 - Article

C2 - 1891278

AN - SCOPUS:0025744609

VL - 30

SP - 23

EP - 27

JO - Pediatric Research

JF - Pediatric Research

SN - 0031-3998

IS - 1

ER -