Effects of glucose infusion on leucine transamination and oxidation in the ovine fetus

Edward A. Liechty, Scott Denne, James A. Lemons, C. Lawrence Kien

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

During fasting of the ewe, the rate of amino acid oxidation by the ovine fetus increases substantially. We hypothesized that the increase in amino acid oxidation derived mainly from reduced protein synthesis. We further hypothesized that fetal glucose supplementation would result in diminished amino acid oxidation. To test these hypotheses, nine ovine fetuses were infused with [15N,1-13C]leucine to determine the rates of leucine appearance and disposal. Simultaneously, the fetal uptake of leucine was determined. Animals were studied in the fed and fasted state. After baseline measurements, glucose was infused into the fetal inferior vena cava at a rate estimated to match the fetal glucose uptake. Results of these studies indicate that leucine nitrogen flux, leucine carbon flux and fetal leucine uptake were constant. Leucine oxidation was increased by 50% in the fasted state (6.3 versus 13.4 ftmol/ min); glucose infusion resulted in a 25% decline in oxidation (to 10.4 /imol/min) in the fasted state, but had no effect in the fed state. Mean leucine umbilical uptake during fasting was 9.3 junol/min, 4.1 ftmol/min less than leucine oxidation. These data suggest that leucine (and potentially other amino acids) may be in negative balance during maternal fasting, and can be spared by supplementation of the fetus with exogenous glucose.

Original languageEnglish
Pages (from-to)423-429
Number of pages7
JournalPediatric Research
Volume30
Issue number5
StatePublished - 1991

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Leucine
Sheep
Fetus
Glucose
Amino Acids
Fasting
Umbilicus
Carbon Cycle
Inferior Vena Cava
Nitrogen
Mothers

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health

Cite this

Effects of glucose infusion on leucine transamination and oxidation in the ovine fetus. / Liechty, Edward A.; Denne, Scott; Lemons, James A.; Kien, C. Lawrence.

In: Pediatric Research, Vol. 30, No. 5, 1991, p. 423-429.

Research output: Contribution to journalArticle

Liechty, Edward A. ; Denne, Scott ; Lemons, James A. ; Kien, C. Lawrence. / Effects of glucose infusion on leucine transamination and oxidation in the ovine fetus. In: Pediatric Research. 1991 ; Vol. 30, No. 5. pp. 423-429.
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