A high-fat diet influences insulin-stimulated posttransport muscle glucose metabolism in rats.
Metabolism
; 46(9): 1101-6, 1997 Sep.
Article
em En
| MEDLINE
| ID: mdl-9284904
ABSTRACT
Because of a failure to detect significant quantities of intracellular glucose, it has been generally accepted that transport rather than phosphorylation is the rate-limiting process of muscle glucose metabolism under most (but not all) physiological conditions. Here, we have measured tissue free levels of the glucose analog 2-deoxy-D-glucose (2DG) in red quadriceps muscle of rats fed a high-fat diet (59% of energy from fat) for 3 weeks, to identify the barrier to insulin-stimulated glucose uptake previously seen in such animals. Measurements were performed on pentobarbital-anesthetized rats following exogenous infusion of radiolabeled 2DG. A glucose clamp was used to maintain plasma insulin at high physiological levels (approximately 120 mU/L). Three other treatment groups representing normal insulin action (chow-fed), extreme glucose uptake (maximal insulin stimulation + hyperglycemia), and insulin resistance with elevated free intracellular glucose (epinephrine infusion) were also studied for comparison. In chow-fed animals, no muscle free 2DG was detected, confirming transport as the rate-limiting process. In fat-fed animals, a significant elevation in muscle free 2DG was observed (P < .01 v chow-fed controls). The elevation was similar in magnitude to that in epinephrine-infused rats, and implied a limitation of insulin action at a posttransport step. This result was confirmed with a more complex modeling analysis. We conclude that posttransport steps influence insulin-stimulated in vivo muscle glucose metabolism in long-term high-fat-fed rats.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Gorduras na Dieta
/
Músculo Esquelético
/
Glucose
/
Insulina
Limite:
Animals
Idioma:
En
Revista:
Metabolism
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Austrália