alpha-Ketobutyrate metabolism in perfused rat liver: regulation of alpha-ketobutyrate decarboxylation and effects of alpha-ketobutyrate on pyruvate dehydrogenase

Journal Article · Fri Nov 01 00:00:00 EST 1985 · Arch. Biochem. Biophys.; (United States)

DOI:https://doi.org/10.1016/0003-9861(85)90226-7· OSTI ID:6194400

Lapointe, D S; Olson, M S

The oxidative decarboxylation and subsequent production of glucose from alpha-ketobutyrate were studied using perfused livers from fasted rats. The production of /sup 14/CO/sub 2/ from alpha-keto-(1-/sup 14/C)butyrate increased monotonically while the production of glucose from alpha-ketobutyrate was biphasic as the perfusate concentration of alpha-ketobutyrate was increased. The biphasic gluconeogenic response using alpha-ketobutyrate as the gluconeogenic precursor was similar to that observed with propionate. The effects of alpha-ketobutyrate infusion on pyruvate decarboxylation were tested and it was found that at low perfusate pyruvate concentrations increasing alpha-ketobutyrate led to increasing inhibition of pyruvate decarboxylation, while at high perfusate pyruvate concentrations an initial inhibition was apparent which did not increase substantially with increasing alpha-ketobutyrate concentrations. The results obtained indicate that the regulation of alpha-ketobutyrate metabolism by oxidative decarboxylation differs significantly from that of pyruvate. In addition, while the rate of gluconeogenesis using alpha-ketobutyrate as a precursor was remarkably similar to that using propionate as a gluconeogenic precursor, the effects of alpha-ketobutyrate on the oxidative decarboxylation of pyruvate were qualitatively different from the effects of propionate on pyruvate metabolism.

• Research Organization: Univ. of Texas Health Science Center, San Antonio
• OSTI ID: 6194400
• Journal Information: Arch. Biochem. Biophys.; (United States), Vol. 2
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CARBON 14 COMPOUNDS
DECARBOXYLATION
CARBOXYLIC ACID SALTS
LIVER
KINETICS
OXIDOREDUCTASES
BIOCHEMISTRY
CARBON DIOXIDE
CARNITINE
RATS
AMINO ACIDS
ANIMALS
BODY
CARBON COMPOUNDS
CARBON OXIDES
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
DIGESTIVE SYSTEM
ENZYMES
GLANDS
HYDROXY ACIDS
LABELLED COMPOUNDS
MAMMALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
OXIDES
OXYGEN COMPOUNDS
RODENTS
VERTEBRATES
VITAMIN B GROUP
VITAMINS
550201* - Biochemistry- Tracer Techniques