Effect of a protein synthetic inhibitor on in vivo estimates of protein synthesis in dogs
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), Vol. 252:5
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CARBON 14 COMPOUNDS
TRACER TECHNIQUES
PROTEINS
BIOSYNTHESIS
TRITIUM COMPOUNDS
CARBON DIOXIDE
DOGS
ENZYME INHIBITORS
FASTING
HEXANOIC ACID
IN VIVO
LEUCINE
METABOLISM
AMINO ACIDS
ANIMALS
CARBON COMPOUNDS
CARBON OXIDES
CARBOXYLIC ACIDS
CHALCOGENIDES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SYNTHESIS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques