Effect of hyperglucagonemia on whole-body leucine metabolism in immature pigs before and during a meal

Journal Article · Tue Mar 01 04:00:00 EST 1988 · American Journal of Physiology; (USA)

OSTI ID:6808897

Ostaszewski, P; Nissen, S ^[1]

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1. Iowa State Univ., Ames (USA)

Leucine metabolism was measured isotopically in 12 immature female pigs to assess the effect of acute hyperglucagonemia on leucine kinetics in both the fed and fasting states. After an overnight fast, immature pigs were infused with {alpha}-({sup 3}H)ketoisocaproate and ({sup 14}C)leucine. After a 2-h equilibration period, an infusion of either saline or 7 pg {center dot} kg{sup {minus}1} {center dot} min{sup {minus}1} of glucagon was begun, which increased plasma glucagon from {approximately}140 to {approximately}640 pg/ml and doubled the insulin concentrations. Two hours later, pigs were fed small meals to which (5,5,5-{sup 2}H{sub 3})leucine was added to trace absorption. By subtracting absorption from total leucine flux, an estimate of endogenous proteolysis during the meal was made. In the fasting state, glucagon increased proteolysis and increased oxidation. No significant glucagon-related changes in any other flux parameters occurred in the fasting state. Ingestion of the meals caused oxidation to increase 41% in control animals, whereas in glucagon-infused animals, oxidation increased 84%. Additional, animals infused with glucagon suppressed endogenous proteolysis 43% after the meal compared with 55% decrease in control animals. These data indicate that glucagon stimulates whole-body proteolysis in both the fasting and fed states.

• OSTI ID: 6808897
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 254:3; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
BIOSYNTHESIS
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
DECOMPOSITION
DOMESTIC ANIMALS
DUAL-ISOTOPE SUBTRACTION TECHNIQUE
FASTING
GLUCAGON
HORMONES
HYDROGEN COMPOUNDS
HYDROLYSIS
INSULIN
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEUCINE
LYSIS
MAMMALS
METABOLISM
ORGANIC ACIDS
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PEPTIDES
POLYPEPTIDES
PROTEINS
SOLVOLYSIS
SWINE
SYNTHESIS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES