Effects of (/sup 15/N)leucine infused at low rates on leucine metabolism in humans

Journal Article · Mon Jul 01 04:00:00 EDT 1985 · Am. J. Physiol.; (United States)

OSTI ID:5246972

Tessari, P; Tsalikian, E; Schwenk, W F; Nissen, S L; Haymond, M W

The present studies were carried out to determine whether infusions of (/sup 15/N)leucine at low rates affect estimates of leucine oxidation and of proteolysis and protein synthesis in humans. Three groups of normal subjects were infused for 3 h with either (/sup 15/N)leucine at a rate of 0.16 or 0.26 mumol X kg-1 X min-1 or saline using (/sup 3/H)leucine and alpha-(/sup 14/C)ketoisocaproate as isotopic tracers of leucine metabolism. Data were analyzed at steady state using both single- and dual-isotope models. Preliminary studies were carried out to characterize the dual-isotope model in humans using infusions of (/sup 3/H)leucine and alpha-(/sup 14/C)ketoisocaproate. In the postabsorptive state estimates of leucine appearance, disappearance, and oxidation derived from the two isotope models were in good agreement. Infusion of stable isotope up to approximately 10% of the leucine carbon flux do not have a significant effect on leucine metabolism, but the data derived from such studies must be properly controlled and interpreted with care because these tracers are not massless.

• Research Organization: Mayo Clinic, Rochester, MN
• OSTI ID: 5246972
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States); ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
DECOMPOSITION
ISOTOPE APPLICATIONS
ISOTOPES
KETO ACIDS
LABELLED COMPOUNDS
LEUCINE
LIGHT NUCLEI
MATHEMATICAL MODELS
METABOLISM
NITROGEN 15
NITROGEN ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
PROTEINS
PROTEOLYSIS
STABLE ISOTOPES
TRACER TECHNIQUES
TRITIUM COMPOUNDS