Insulin response of components of whole-body and muscle carbohydrate metabolism in humans.
We measured total body insulin-mediated glucose uptake, carbohydrate oxidation, storage (nonoxidative disposal), muscle glycogen synthase activity, and muscle glucose 6-phosphate (G-6-P) content in response to five levels of insulinemia (means 16, 52, 152, 573, and 5,550 microU/ml) in 16 male glucose-tolerant volunteers. Insulin dissociation constants (KDs) for disposal, storage, and synthase activity (but not for oxidation) are coincident, suggesting that storage via glycogen synthesis could be a major determinant of glucose disposal. Increases in glucose disposal were associated with decreases in muscle G-6-P concentration. These data suggest that the principal control over carbohydrate disposal is exerted after G-6-P. The coincidence of insulin sensitivities for disposal, storage, and synthase activity suggest that storage via glycogen synthesis could be a major determinant of glucose disposal.
Young
A A
AA
Clinical Diabetes and Nutrition Section, National Institute of Arthritis and Digestive and Kidney Diseases, Phoenix, Arizona 85016.
Bogardus
C
C
Stone
K
K
Mott
D M
DM
D050260:Carbohydrate Metabolism; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000502:physiology*; D007700:Kinetics; D008297:Male; D009132:Muscles / Q000378:metabolism*
D005958:Glucosephosphates; D007328:Insulin; D019298:Glucose-6-Phosphate