title: [Methodologic studies for the measurement of kinetic parameters of the metabolism of whole body protein in association with measurements of energy metabolism in rats].
abstract: In 3 successive experiments with growing rats the suitability of pulse labelling with [15N]glycine, linked with a 14C labelling by means of [14C]lysine (experiment 3), was tested for the determination of kinetic parameters of the protein metabolism of the whole body by the application of the compartment model in comparison with pulse labelling with a 15N amino acid mixture (experiment 2) and long-time labelling with 15N with 15N labelled wheat in the feed (experiment 1) under standardized experiment conditions. In simultaneously carried out measurings of energy metabolism with parallel groups of animals the comparability of the metabolic development was studied. The ascertained values of protein synthesis rate, protein catabolism rate and re-utilization rate showed insignificant differences only between the 3 15N tracer variants (with certain limitations for the 'protein turnover' (P)-group of experiment 2) in comparison with errors of the applied methods, from which conclusions can be drawn for the suitability of [15N] glycine as tracer, at least under the experiment conditions tested. The protein synthesis and degradation rates ascertained from 14CO2 excretion in experiment 3 were clearly below those average values ascertained with 15N. The differences in the average heat production between the main periods of the 3 experiments were statistically insignificant.
mesh_terms: D000821:Animal Feed; D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D004734:Energy Metabolism; D005998:Glycine / Q000378:metabolism; D007700:Kinetics; D008239:Lysine / Q000378:metabolism; D008297:Male; D009587:Nitrogen Isotopes; D014176:Protein Biosynthesis; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D009587:Nitrogen Isotopes; D011506:Proteins; D002245:Carbon Dioxide; D008239:Lysine; D005998:Glycine
vernacular_title: Methodische Untersuchungen zur Messung von kinetischen Parametern des Gesamtkörperproteinstoffwechsels in Verbindung mit Energieumsatzmessungen an Ratten.