Threonine is catabolized by L-threonine 3-dehydrogenase and threonine dehydratase in hepatocytes from domestic cats (Felis domestica)

Victoria A. Hammer, Quinton Rogers, Richard A. Freedland

Research output: Contribution to journalArticle

15 Scopus citations

Abstract

Isolated hepatocytes were used to study threonine catabolism in kittens, and dietary threonine and crude protein were varied to study enzyme adaptation. Cells were isolated from 21-wk-old kittens which had been fed diets containing threonine at 4 or 8 g/kg of diet with either 200 or 500 g crude protein/kg of diet (2 x 2 factorial, n = 4/group). Production of CO2, glucose and various metabolites from [U-14C]threonine were measured. Inclusion of 10 mmol/L glycine, or glycine in combination with 10 mmol/L acetaldehyde + ethanol, in the incubation medium decreased formation of 14CO2 and [14C]glucose. At the same time, large amounts of [14C]glycine but no [14C]ethanol was formed. Inclusion of 10 mmol/L 2- ketobutyrate + 2-hydroxybutyrate decreased 14C02 but not [14C]glucose production and resulted in the formation of [14C]2-hydroxybutyrate. Under all incubation conditions, 14CO2 and [12C]glucose production changed in response to alterations in dietary protein but not dietary threonine. It appears that threonine dehydratase and L-threonine 3-dehydrogenase, but not threonine aldolase, are active pathways for threonine metabolism in cats, and both enzymes are sensitive to levels of dietary protein.

Original languageEnglish (US)
Pages (from-to)2218-2226
Number of pages9
JournalJournal of Nutrition
Volume126
Issue number9
StatePublished - Sep 1 1996

Keywords

  • feline
  • L-threonine 3-dehydrogenase
  • threonine aldolase
  • threonine dehydratase

ASJC Scopus subject areas

  • Food Science
  • Medicine (miscellaneous)

Fingerprint Dive into the research topics of 'Threonine is catabolized by L-threonine 3-dehydrogenase and threonine dehydratase in hepatocytes from domestic cats (Felis domestica)'. Together they form a unique fingerprint.

  • Cite this