Effect of a protein synthetic inhibitor on in vivo estimates of protein synthesis in dogs

Journal Article · Fri May 01 04:00:00 EDT 1987 · Am. J. Physiol.; (United States)

OSTI ID:5723035

Schwenk, W F; Rubanyi, E; Haymond, M W

In vivo estimates of nonoxidative leucine disappearance have frequently been used as estimates of leucine incorporation into protein. To attempt to assess this extrapolation to protein synthesis, seven overnight fasted dogs received primed 4-h infusions of emetine, an alkaloid known to inhibit protein synthesis at the translational level. Protein metabolism was studied using infusions of (1-/sup 14/C)leucine and ..cap alpha..-(4,5-/sup 3/H)ketoisocaproate (KIC) and the steady-state specific activities of the leucine moiety (e.g., (/sup 14/C)KIC and (/sup 3/H)leucine) reciprocal to the infused isotopes as estimates of intracellular leucine specific activities. Plasma leucine and KIC concentrations increased, as did leucine oxidation. Estimates of nonoxidative leucine disappearance decreased by approx. 70%, and estimates of the endogenous leucine rate of appearance decreased by approx. 40% using either the /sup 14/C or /sup 3/H data. They conclude that, although in vivo estimates of leucine metabolism are not quantitative, rapid changes in whole-body estimates of protein synthesis can be predicted during infusion of labeled leucine.

• Research Organization: Mayo Clinic and Foundation, Rochester, MN
• OSTI ID: 5723035
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 252:5; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
BIOSYNTHESIS
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBOXYLIC ACIDS
CHALCOGENIDES
DOGS
ENZYME INHIBITORS
FASTING
HEXANOIC ACID
IN VIVO
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEUCINE
MAMMALS
METABOLISM
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PROTEINS
SYNTHESIS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES