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Titre du document / Document title

Uniaxial Cyclic Stretch Increases Glucose Uptake into C2C12 Myotubes through a Signaling Pathway Independent of Insulin-like Growth Factor I

Auteur(s) / Author(s)

Iwata M. (1) ; Suzuki S. ; Hayakawa K. ; Inoue T. ; Naruse K. ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) 1Program in Physical and Occupational Therapy, Nagoya University Graduate School of Medicine, Higashi-ku, Nagoya, Japan

Résumé / Abstract

Insulin-like growth factor I (IGF-I), an autocrine/paracrine growth factor involved in myogenesis, has rapid effects on muscle metabolism. In a manner analogous to insulin and mechanical stimuli such as stretch, IGF-I stimulates glucose transport through recruitment of glucose transporters to surface membranes in skeletal muscles. It is known that IGF-I is secreted from skeletal muscle cells in response to stretch. Therefore, we examined whether IGF-I is involved in the mechanism by which mechanical stretch regulates glucose transport using cultured C2C12 myotubes. IGF-I increased 2-deoxy- D-glucose (2-DG) uptake, and this created an additive effect with mechanical stretch, suggesting that these stimuli enhance glucose transport through different mechanisms. In fact, IGF-I-stimulated 2-DG uptake was not blocked by dantrolene (an inhibitor of Ca 2+release from sarcoplasmic reticulum), whereas the stretch-stimulated effect was abolished. Conversely, the IGF-I-stimulated 2-DG uptake was prevented by phosphatidylinositol 3-kinase inhibitor wortmannin, which did not prevent the stretch-stimulated 2-DG uptake. In addition, experiments using media conditioned by stretched myotubes indicated that a mechanically induced release of locally acting autocrine/paracrine growth factors was not sufficient for induction of 2-DG uptake. Thus, our results demonstrate that mechanical stretch signaling for glucose transport is independent of the mechanism through which IGF-I increases this transport.

Revue / Journal Title

Hormone and metabolic research    ISSN  1439-4286 

Source / Source

2009, vol. 41, no01, pp. 16-22 [7 page(s) (article)]

Langue / Language

Anglais

Editeur / Publisher

Thieme, Stuttgart, ALLEMAGNE  (1995) (Revue)

Mots-clés d'auteur / Author Keywords

growth factor

;

skeletal muscle

;

autocrine/paracrine

;

Localisation / Location

35400060111987.0004

Tous droits réservés © Georg Thieme Verlag Stuttgart, New York, 2009
Nº notice refdoc (ud4) : 20836353



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