Amino acid uptake by the fetal ovine hindlimb under normal and euglycemic hyperinsulinemic states

R. B. Wilkening, D. W. Boyle, C. Teng, G. Meschia, F. C. Battaglia

Research output: Contribution to journalArticle

19 Scopus citations

Abstract

As part of an effort to establish the contribution of different fetal organs to fetal amino acid metabolism, we measured in nine sheep fetuses the uptake of 27 amino acids by the hindlimb under normal conditions and conditions of euglycemic hyperinsulinemia. The fetal hindlimb is representative of nonvisceral tissues, which in the mature fetus account for ~70% of fetal weight and 30% of fetal O2 consumption. In the normal condition, there was a significant uptake of 21 amino acids for a net total nitrogen uptake of 132 ± 21 mg N · day-1 · 100 g-1. The amino acids taken up by the fetal limb included alanine and glutamine. In addition, the fetal limb had significant glutamate and serine uptakes. Because glutamate flows from fetus to placenta and there is no fetal uptake of maternal serine, this indicates production and interorgan transport of these amino acids within the fetus. Insulin infusion significantly decreased the arterial concentration of every amino acid with the exception of cystathionine and significantly increased limb blood flow and glucose uptake. It significantly increased the limb uptake of alanine, asparagine, glycine, isoleucine, methionine, and tyrosine, decreased the uptake of aspartate, and produced no significant change in the net total nitrogen uptake, which remained similar to control (137 ± 16 mg N · day-1 · 100 g-1).

Original languageEnglish (US)
Pages (from-to)E72-E78
JournalAmerican Journal of Physiology - Endocrinology and Metabolism
Volume266
Issue number1 29-1
StatePublished - Jan 1 1994

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Keywords

  • amino acids
  • blood flow
  • glucose clamp
  • glucose uptake
  • insulin
  • lactate release
  • oxygen uptake
  • sheep fetus
  • skeletal muscle

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Physiology
  • Physiology (medical)

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