Insulin-like growth factor 1 inhibits glucocorticoid-induced glutamine synthetase activity in cultured L6 rat skeletal muscle cells

Citation
K. Kimura et al., Insulin-like growth factor 1 inhibits glucocorticoid-induced glutamine synthetase activity in cultured L6 rat skeletal muscle cells, NEUROSCI L, 302(2-3), 2001, pp. 154-156
Citations number
13
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences & Behavoir
Journal title
NEUROSCIENCE LETTERS
ISSN journal
0304-3940 → ACNP
Volume
302
Issue
2-3
Year of publication
2001
Pages
154 - 156
Database
ISI
SICI code
0304-3940(20010420)302:2-3<154:IGF1IG>2.0.ZU;2-H
Abstract
We previously demonstrated the preventive effect of insulin-like growth fac tor 1 (IGF-1) on steroid myopathy in rats. However, the mechanism by which IGF-1 inhibits steroid myopathy remains unclear. Recent studies have reveal ed that glutamine synthetase (GS) is induced by glucocorticoid and may be r elated to the development of steroid myopathy. In this study, we examined w hether IGF-1 affected steroid-induced enhancement of GS activity in L6 rat skeletal muscle cells. Dexamethasone(10(-6) M) significantly increased GS a ctivity in L6 cells(P < 0.01), IGF-1 dose-dependently inhibited dexamethaso ne-induced GS activity. Addition of IGF-1 (750 ng/ml) decreased GS activity to approximately 50% of that with dexamethasone alone (P < 0.01). These re sults suggest that a decrease in GS activity may be involved in the prevent ive effect of IGF-1 on steroid myopathy. (C) 2001 Elsevier Science Ireland Ltd. Ail rights reserved.