Direct vs. indirect pathway of hepatic glycogen synthesis as a function of glucose infusion rate

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

OSTI ID:7119066

Bagby, G J; Lang, C H; Johnson, J L; Blakesly, H L; Spitzer, J J

This study was initiated to determine the influence of the rate of exogenous glucose administration on liver glycogen synthesis by the direct (glucose uptake and incorporation into glycogen) vs the indirect pathway (glucose degradation to 3-carbon intermediates, e.g., lactate, prior to incorporation into glycogen). Catheterized rats were fasted 2 days prior to receiving a 3 hr infusion of glucose at rates of 0 to 230 ..mu..mol/min/kg containing tracer (6-/sup 3/H)- and (U-/sup 14/C)-glucose. Plasma glucose (r = 0.80), insulin (r = 0.90) and lactate (r = 0.84) were correlated with glucose infusion rate. The rate of liver glycogen deposition (0.46 +/- 0.03 ..mu..mol/min/g) did not differ between a glucose infusion rate of 20 and 230 ..mu..mol/min/kg. At the lowest and highest glucose infusion rates hepatic glycogenesis accounted for 87 +/- 6 and 9 +/- 1% of the total glucose load, respectively. The percent contribution of the direct pathways to glycogen deposition ((/sup 3/H) specific activity in hepatic glycogen/(/sup 3/H) specific activity in plasma glucose) increased from 16 +/- 3 to 83 +/- 5% from lowest to highest glucose infusion rates (prevailing plasma glucose concentrations: 9 +/- 1 and 21 +/- 2 mM, respectively). The results indicate that the relative contribution of the direct and indirect pathways of glucogen synthesis are dependent upon the glucose load or plasma glucose concentration.

• Research Organization: Louisiana State Univ. Medical Center, New Orleans
• OSTI ID: 7119066
• 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
ALDEHYDES
ANIMALS
BIOLOGICAL PATHWAYS
BIOSYNTHESIS
BODY
CARBOHYDRATES
CARBON 14 COMPOUNDS
DIGESTIVE SYSTEM
GLANDS
GLUCOSE
GLYCOGEN
HEXOSES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIVER
MAMMALS
METABOLISM
MONOSACCHARIDES
ORGANIC COMPOUNDS
ORGANS
POLYSACCHARIDES
RATS
RODENTS
SACCHARIDES
SYNTHESIS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES