Relationship between plasma and tissue parameters of leucine metabolism

Conference · Wed Mar 05 04:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:7034074

Vazquez, J A; Paul, H S; Adibi, S A

Using a primed continuous infusion of (1-/sup 14/C) leucine, the authors investigated parameters of leucine metabolism in plasma, expired air, and tissues of fed and 48-hour starved rats. The ratios of muscle/plasma specific activity of ..cap alpha..-ketoisocaproate (KIC) in fed and starved rats, respectively were not significantly different from one (1.07 +/- 0.14 and 0.97 +/- 0.10, mean +/- SE, 7 rats). The ratio of muscle/plasma specific activity of leucine was also not significantly different from one (0.86 +/- 0.11) in fed rats, but was significantly lower than one (0.80 +/- 0.07) in starved rats. The rate of leucine oxidation was approximately 32% higher when calculated based on plasma KIC rather than leucine specific activity. However, starvation significantly increased the rate of leucine oxidation with either specific activity. The rate of leucine incorporation into whole body protein was unaffected by starvation (32.7 +/- 3.5 vs 36.1 +/- 2.5 ..mu..mol/100 g/h), but the incorporation into total protein of liver (1350 +/- 140 vs 780 +/- 33 nmol) and of skeletal muscle (1940 +/- 220 vs 820 +/- 60 nmol) was significantly decreased. The authors conclude that a) leucine or KIC specific activity in muscle is better predicted by plasma KIC than leucine specific activity, and b) the tracer infusion technique is valid for the study of leucine oxidation but not for leucine incorporation into whole body protein.

• Research Organization: Univ. of Pittsburgh School of Medicine, PA
• OSTI ID: 7034074
• Report Number(s): CONF-8604222-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:4
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
BIOLOGICAL MATERIALS
BLOOD
BLOOD PLASMA
BODY
BODY FLUIDS
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
DIGESTIVE SYSTEM
GLANDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEUCINE
LIVER
MAMMALS
MATERIALS
METABOLISM
MUSCLES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RATS
RODENTS
TRACER TECHNIQUES
VERTEBRATES