Mechanisms limiting glycogen storage in muscle during prolonged insulin stimulation

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

OSTI ID:6036742

Richter, E A; Hansen, S A; Hansen, B F ^[1]

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1. Univ. of Copenhagen (Denmark)

The extent to which muscle glycogen concentrations can be increased during exposure to maximal insulin concentrations and abundant glucose was investigated in the isolated perfused rat hindquarter preparation. Perfusion for 7 h in the presence of 20,000 {mu}U/ml insulin and 11-13 mM glucose increased muscle glycogen concentrations to maximal values 2, 3, and 3.5 times above normal fed levels in fast-twitch white, slow-twitch red, and fast-twitch red fibers, respectively. Glucose uptake decreased from 34.9 {mu}mol{center dot}g{sup {minus}1}{center dot}h{sup {minus}1} at 0 h to 7.5 after 7 h of perfusion. During the perfusion muscle glycogen synthase activity decreased and free intracellular glucose and glucose 6-phosphate increased indicating that glucose disposal was impaired. However, glucose transport as measured by the uptake of 3-O-({sup 14}C)methyl-D-glucose was also markedly decreased after 5 and 7 h of perfusion compared with initial values. Total muscle water concentration decreased during glycogen loading of the muscles. Mechanisms limiting glycogen storage under maximal insulin stimulation include impaired insulin-stimulated membrane transport of glucose as well as impaired intracellular glucose disposal.

• OSTI ID: 6036742
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 255:5; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

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59 BASIC BIOLOGICAL SCIENCES
BIOLOGICAL FUNCTIONS
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
FUNCTIONS
GLYCOGEN
HORMONES
HYDROGEN COMPOUNDS
HYDROXY ACIDS
INSULIN
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LACTIC ACID
METABOLISM
MUSCLES
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PEPTIDE HORMONES
PHYSIOLOGY
POLYSACCHARIDES
SACCHARIDES
TRACER TECHNIQUES
WATER