Phenylalanine flux in adult men: Estimates with different tracers and route of administration

Journal Article · Fri Jun 01 04:00:00 EDT 1990 · Metabolism, Clinical and Experimental; (USA)

DOI:https://doi.org/10.1016/0026-0495(90)90018-8· OSTI ID:6708127

Krempf, M; Hoerr, R A; Marks, L; Young, V R ^[1]

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1. Massachusetts Institute of Technology, Cambridge (USA)

The kinetics of three different tracers of phenylalanine were studied when continuously infused together either by an intravenous (IV) or intragastric (IG) route in six young healthy men during a fasting state. During IV infusion, mean flux values were 39.2 +/- 1.8, 40 +/- 3, 41.8 +/- 3.6 mumol.kg-1.h-1 for L-(ring-2H5), (15N), and L-(1-13C)phenylalanine, respectively (differences not significant). Fluxes were higher (P less than .001) during IG than IV infusion, indicating a disappearance of tracer during the first pass through the splanchnic area. Also, higher fluxes were found for (ring-2H5)phenylalanine (74 +/- 6.23 mumol.kg-1.h-1) compared with (15N) and L-(1-13C)phenylalanine (54.24 +/- 4.7 and 61.15 +/- 5.3 mumol.kg-1.h-1) during IG infusion. Proton exchange might explain this difference, possibly limiting in vivo use of this label when the tracer is to be administered by the IG route.

• OSTI ID: 6708127
• Journal Information: Metabolism, Clinical and Experimental; (USA), Journal Name: Metabolism, Clinical and Experimental; (USA) Vol. 39:6; ISSN METAA; ISSN 0026-0495
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
CARBON 13
CARBON ISOTOPES
CARBOXYLIC ACIDS
DEUTERIUM
DIGESTIVE SYSTEM
DYNAMIC FUNCTION STUDIES
EVEN-ODD NUCLEI
FASTING
GASTROINTESTINAL TRACT
HYDROGEN ISOTOPES
INJECTION
INTAKE
INTRAVENOUS INJECTION
ION EXCHANGE
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MAMMALS
MAN
METABOLISM
NITROGEN 15
NITROGEN ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
ORAL ADMINISTRATION
ORGANIC ACIDS
ORGANIC COMPOUNDS
PHENYLALANINE
PRIMATES
STABLE ISOTOPES
TRACER TECHNIQUES
VERTEBRATES