title: [15N]methacetin urine test to measure liver function: methodology for application in pediatrics.
abstract: A simple, noninvasive test is proposed to measure the activity of the hepatocellular monooxygenase system in vivo. Elimination rates of the stable isotope 15N are measured in urine after an oral dose of the 15N-labeled phenacetin homologue [15N]methacetin. Different forms of obtaining and expressing results are investigated in order to determine optimum methodology and differentiation for clinical application in pediatrics. The best discriminating power and reliability of results are seen with the measurement of 15N elimination half-life. For follow-up, a more easily measured parameter--eliminated dose over 9 h--is sufficient. In the latter case, only total nitrogen and 15N contents of a collective urine sample are measured.
authors.affiliation: Central Institute for Isotope and Radiation Research, Academy of Sciences of the G.D.R., Leipzig.
authors.forename: P
authors.initials: P
authors.lastname: Krumbiegel
authors.forename: B
authors.initials: B
authors.lastname: Teichmann
authors.forename: H
authors.initials: H
authors.lastname: Faust
authors.forename: W
authors.initials: W
authors.lastname: Braun
mesh_terms: D000081:Acetamides / Q000493:pharmacokinetics / Q000652:urine*; D000293:Adolescent; D001711:Biotransformation; D002648:Child; D002675:Child, Preschool; D006207:Half-Life; D006801:Humans; D007223:Infant; D008107:Liver Diseases / Q000175:diagnosis; D008111:Liver Function Tests / Q000379:methods*; D008657:Metabolic Clearance Rate; D006899:Mixed Function Oxygenases / Q000652:urine; D009587:Nitrogen Isotopes; D011237:Predictive Value of Tests
chemical_list: D000081:Acetamides; D009587:Nitrogen Isotopes; C035495:methacetin; D006899:Mixed Function Oxygenases