High branched-chain α-keto acid intake, branched-chain α-keto acid dehydrogenase activity, and plasma and brain amino acid and plasma keto acid concentrations in rats

Pamela L. Crowell, Kevin P. Block, Joyce J. Repa, Nimbe Torres, M. Daud Nawabi, Maria G. Buse, Alfred E. Harper

Research output: Contribution to journalArticlepeer-review

14 Scopus citations

Abstract

Diets containing high quantities of individual branched-chain α-keto acids (BCKAs) or a combination of BCKAs as used for treatment of renal disease were fed to rats. When the diet contained a single BCKA, its concentration was high in plasma and the concentration of its corresponding amino acid was high in plasma and brain. Liver BCKA dehydrogenase (BCKD) was 42% active in control rats. Consumption of diets containing 0.38 mol/kg diet of α-ketoisocaproate (KIC), α-keto-β-methylvalerate (KMV), or α-ketoisovalerate (KIV) resulted in complete activation of liver BCKD. Consumption of the diet containing the combination of BCKAs increased basal BCKD activity of liver twofold. Muscle BCKD was activated after feeding the KIV diet (2-fold), the KIC diet (3-fold), and the KMV diet (15-fold). Total BCKD activity of liver and muscle was unaffected by dietary treatments. Activation of liver and muscle BCKD by dietary BCKA is consistent with their ability to inhibit BCKD kinase in vitro.

Original languageEnglish (US)
Pages (from-to)313-319
Number of pages7
JournalAmerican Journal of Clinical Nutrition
Volume52
Issue number2
DOIs
StatePublished - Jan 1 1990

Keywords

  • L-allosioleucine
  • amino acid concentrations
  • branched-chain α-keto acid dehydrogenase
  • branched-chain α-keto acids
  • α-ketoisocaproate

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics

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