Characterization of the growth and degradation of glycogen in the liver

Conference · Thu May 01 00:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6985649

Youn, J; Bergman, R

The patterns of the growth and degradation of hepatic glycogen were studied using a computer model. The database was that of Devos and Hers on the distribution of label in glycogen from (1-/sup 14/C) galactose injected at different times after the start of refeeding 40 h fasted mice. The data was simulated to examine the following hypotheses (H): Glycogen Synthesis H.S1: all glycogen molecules grow simultaneously. H.S2: at each moment of synthesis only a fixed number of molecules grow. H.S3: the number of growing molecules increases linearly with respect to time. H.S4: increase in the number of growing molecules is accelerated as glycogen is synthesized. Glycogen Degradation H.D1: glycogen molecules to be attacked by degrading enzymes are randomly chosen. H.D2: glycogen molecules are degraded sequentially in the reverse order of synthesis. H.D3: glycogen molecules have different probabilities of degradation depending upon the time of synthesis. The growth and degradation according to hypotheses S4 and D3, respectively, could best account for the data. The modelling study predicts that, at the beginning of refeeding, only a small number of molecules grow. But, as glycogen is synthesized, the rate of seeding of new glycogen molecules increases with time, causing a nonlinear proliferation of the number of growing molecules. During degradation glycogen molecules synthesized later have a greater chance to be degraded first, a characteristic which may be explained by the rosette structure of liver glycogen.

• Research Organization: Univ. of Southern California, Los Angeles
• OSTI ID: 6985649
• Report Number(s): CONF-8606151-; TRN: 86-039166
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
GLYCOGEN
BIOSYNTHESIS
METABOLISM
CARBON 14 COMPOUNDS
COMPUTERIZED SIMULATION
LIVER
MATHEMATICAL MODELS
MICE
MOLECULES
TRACER TECHNIQUES
ANIMALS
BODY
CARBOHYDRATES
DIGESTIVE SYSTEM
GLANDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
ORGANIC COMPOUNDS
ORGANS
POLYSACCHARIDES
RODENTS
SACCHARIDES
SIMULATION
SYNTHESIS
VERTEBRATES
550501* - Metabolism- Tracer Techniques