title: [Conditions of feasibility and stability in the measurement of protein synthesis using 15N glycine in intensive care patients].
abstract: The rates of nitrogen flux and protein synthesis in the whole body were measured in two intensive care (ICU) patients on two occasions separated by a period of 24 h. Rates of flux and synthesis were estimated from 15N excretion in urinary ammonia after a slow injection of 15N glycine over a period of 1 h. The aim of the present study was to evaluate the feasibility and the reproducibility of the method. The variation of nitrogen flux was between 6 and 9%, and for synthesis between 7 and 9%. Skeletal muscle protein breakdown was measured from urinary 3, methylhistidine excretion. The muscle contribution to the whole body breakdown rate was 32 and 41% for one patient and 48 and 51% for the other one. The combination of measurement of 15N excretion after a single dose of 15N glycine with that of urinary 3, methylhistidine provided a reproducible method for measuring whole body protein synthesis in ICU patients. It could be repeated at short intervals and gave useful comparative information provided that conditions were carefully standardized.
mesh_terms: D000293:Adolescent; D000328:Adult; D003422:Critical Care; D005998:Glycine; D006801:Humans; D008297:Male; D009124:Muscle Proteins / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D009587:Nitrogen Isotopes; D014176:Protein Biosynthesis
chemical_list: D009124:Muscle Proteins; D009587:Nitrogen Isotopes; D009584:Nitrogen; D005998:Glycine
vernacular_title: Conditions de réalisation et stabilité de mesure des synthèses protéiques à l'aide de la 15N glycine chez les patients de réanimation.