title: [Procedure for calculating various parameters of the metabolism of amino acid mixtures].
abstract: For the evaluation of indirect calorimetry, elements are used, which specify the relation between nitrogen (N) excretion and amount of oxidized amino acids (AS/N) and between nitrogen excretion and oxygen-/carbon dioxide-exchange of the corresponding amounts of amino acids (O2/N, CO2/N). These elements are only valid for the amino acid mixture which was used for their determination, and only under the condition of complete combustion of deaminized amino acid skeletons. We developed a computer program, which is able to simulate complete oxidation, maximal gluconeogenesis, and maximal lipogenesis for a given amino acid mixture of any composition. The parameters AS/N, O2/N and CO2/N were calculated by the program for various parenteral amino acid solutions. Range of error was determined exemplarily for the use of standard parameters. The calculations demonstrate errors up to 50% for the calculation of substrate turnover in indirect calorimetry, depending on composition and actual metabolism of amino acid mixtures. As long as these influencing factors are not known in stress metabolism, we recommend to use those elements, which were calculated for the amino acid solution in use, assuming complete combustion.
authors.affiliation: Klinik für Anästhesiologie, Johannes Gutenberg-Universität, Mainz.
authors.forename: U
authors.initials: U
authors.lastname: Fauth
authors.forename: W
authors.initials: W
authors.lastname: Heinrichs
authors.forename: I
authors.initials: I
authors.lastname: Puénte-Gonzales
authors.forename: I
authors.initials: I
authors.lastname: Tzanova
authors.forename: M
authors.initials: M
authors.lastname: Halmágyi
mesh_terms: D000596:Amino Acids / Q000008:administration & dosage* / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002151:Calorimetry; D002153:Calorimetry, Indirect; D002245:Carbon Dioxide / Q000097:blood; D003422:Critical Care; D002149:Energy Intake / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology*; D006501:Hepatic Encephalopathy / Q000097:blood; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood; D009584:Nitrogen / Q000652:urine; D010100:Oxygen / Q000097:blood; D010289:Parenteral Nutrition, Total / Q000379:methods*; D014947:Wounds and Injuries / Q000097:blood
chemical_list: D000596:Amino Acids; D001786:Blood Glucose; D002245:Carbon Dioxide; D009584:Nitrogen; D010100:Oxygen
vernacular_title: Verfahren zur Berechnung verschiedener Parameter des Stoffwechsels von Aminosäurengemischen.