Anabolic regulation of gluconeogenesis by insulin in isolated rat hepatocytes

Journal Article · Fri Nov 01 04:00:00 EST 1985 · Arch. Biochem. Biophys.; (United States)

DOI:https://doi.org/10.1016/0003-9861(85)90244-9· OSTI ID:6194332

Mohan, C; Bessman, S P

The role of substrate availability in the regulation of gluconeogenesis in isolated rat hepatocytes was studied using (U-/sup 14/C)alanine as a tracer in the presence of different concentrations of L-alanine in the incubation medium. At low alanine concentrations (0.5 mM) insulin decreased the /sup 14/C incorporation into the glucose pool and increased the incorporation of tracer carbons into the protein and lipid pools and into CO/sub 2/. The net radioactivity lost from the glucose pool was only a small percentage of the total increase in the activity of the protein, lipid, CO/sub 2/, or glycogen pools, supporting the notion that the effect of insulin in diminishing gluconeogenesis is secondary to its effects on pathways using pyruvate. At higher concentrations of alanine (2.5, 5.0, and 10.0 mM) in the incubation medium insulin increased the movement of alanine carbons into protein and glucose. These results were further confirmed by using (U-/sup 14/C)lactate. The increases in observed specific activity of glucose following insulin administration would not be possible if insulin acted by affecting the activity of any enzyme directly involved in the formation or utilization of pyruvate, most of which have been proposed as sites of insulin action. Data presented show that insulin inhibits gluconeogenesis by affecting a change in substrate availability.

• Research Organization: Univ. of Southern California, Los Angeles
• OSTI ID: 6194332
• Journal Information: Arch. Biochem. Biophys.; (United States), Journal Name: Arch. Biochem. Biophys.; (United States) Vol. 2; ISSN ABBIA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL PATHWAYS
CARBOHYDRATES
CARBON 14 COMPOUNDS
GLUCOSE
GLYCOGEN
HEXOSES
HORMONES
INSULIN
KINETICS
LABELLED COMPOUNDS
LIPIDS
LIVER CELLS
MAMMALS
METABOLISM
MONOSACCHARIDES
ORGANIC COMPOUNDS
PEPTIDE HORMONES
POLYSACCHARIDES
RATS
RODENTS
SACCHARIDES
SOMATIC CELLS
VERTEBRATES