title: Assessment of effects of amino acids and branched chain keto acids on leucine oxidation in human lymphocytes.
abstract: Effects of amino acids and branched chain keto acids on leucine transamination and oxidation were assessed in peripheral human lymphocytes. Isoleucine (80-200 mumol/l) and valine (250-500 mumol/l) diminished transamination and oxidation of leucine up to 25%, glutamine (50-1000 mumol/l) up to 55%. alpha-Ketoisocaproic acid (KIC; 200 mumol/l) augmented the activity state of branched chain keto acid dehydrogenase by 40%. It is concluded that in peripheral human lymphocytes (1) isoleucine, valine and glutamine are physiological inhibitors of leucine catabolism, and (2) leucine can promote its own degradation via KIC.
authors.affiliation: Department of Medicine, University of Göttingen, FRG.
authors.forename: G
authors.initials: G
authors.lastname: Schäfer
authors.forename: P
authors.initials: P
authors.lastname: Schauder
mesh_terms: D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide); D000293:Adolescent; D000328:Adult; D000409:Alanine / Q000494:pharmacology; D000596:Amino Acids / Q000494:pharmacology*; D005260:Female; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D005973:Glutamine / Q000494:pharmacology; D005998:Glycine / Q000494:pharmacology; D006801:Humans; D007532:Isoleucine / Q000494:pharmacology; D007651:Keto Acids / Q000494:pharmacology*; D007658:Ketone Oxidoreductases / Q000097:blood*; D007930:Leucine / Q000097:blood*; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009097:Multienzyme Complexes / Q000097:blood*; D010084:Oxidation-Reduction / Q000187:drug effects; D014633:Valine / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D005971:Glutamates; D007651:Keto Acids; D009097:Multienzyme Complexes; D007532:Isoleucine; D005973:Glutamine; D018698:Glutamic Acid; D007658:Ketone Oxidoreductases; D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide); D007930:Leucine; D014633:Valine; D000409:Alanine; D005998:Glycine