|
|
||||||||
Departments of Cellular and Molecular Physiology and Surgery, Pennsylvania State College of Medicine, Hershey, Pennsylvania 17033
The present study determined whether acute alcohol (ethanol; EtOH) intoxication in rats impaired components of the insulin- and IGF-I-signaling pathway in skeletal muscle. Rats were administered EtOH, and 2.5 h thereafter either insulin, IGF-I, or saline was injected and the gastrocnemius removed. EtOH did not alter the total amount or tyrosine phosphorylation of the insulin receptor, IGF-I receptor, insulin receptor substrate (IRS)-1, or protein kinase B (PKB)/Akt under basal or hormone-stimulated conditions. In contrast, the ability of insulin or IGF-I to phosphorylate T389 and T421/S424 on S6K-1 was markedly diminished by EtOH, and these changes were associated with a reduction in the phosphorylation of the ribosomal protein S6. Under basal conditions, EtOH altered the distribution of eukaryotic initiation factor (eIF)4E, as evidenced by a decreased amount of active eIF4E · eIF4G complex, an increased amount of inactive eIF4E · 4E-binding protein (BP)1 complex, and decreased 4E-BP1 phosphorylation. In contrast, EtOH did not impair the ability of either hormone to reverse the changes in eIF4E distribution or 4E-BP1 phosphorylation. Pretreatment with a glucocorticoid receptor antagonist was unable to attenuate either the basal EtOH-induced changes in eIF4E distribution or the impaired ability of IGF-I to stimulate S6K1 and S6 phosphorylation. Hence, acute alcohol intoxication alters selected aspects of translational control under both basal and anabolic hormone-stimulated conditions in skeletal muscle in a glucocorticoid-independent manner.
ethanol; p70 S6; eukaryotic initiation factor 4E; eukaryotic initiation factor 4G; gastrocnemius; rat
This article has been cited by other articles:
![]() |
C. H. Lang Elevated plasma free fatty acids decrease basal protein synthesis, but not the anabolic effect of leucine, in skeletal muscle Am J Physiol Endocrinol Metab, September 1, 2006; 291(3): E666 - E674. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Q. Hong-Brown, A. M. Pruznak, R. A. Frost, T. C. Vary, and C. H. Lang Indinavir alters regulators of protein anabolism and catabolism in skeletal muscle Am J Physiol Endocrinol Metab, September 1, 2005; 289(3): E382 - E390. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Q. Hong-Brown, C. R. Brown, and C. H. Lang Indinavir impairs protein synthesis and phosphorylations of MAPKs in mouse C2C12 myocytes Am J Physiol Cell Physiol, November 1, 2004; 287(5): C1482 - C1492. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. H. Lang and R. A. Frost Differential effect of sepsis on ability of leucine and IGF-I to stimulate muscle translation initiation Am J Physiol Endocrinol Metab, October 1, 2004; 287(4): E721 - E730. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. H. Lang, R. A. Frost, E. Svanberg, and T. C. Vary IGF-I/IGFBP-3 ameliorates alterations in protein synthesis, eIF4E availability, and myostatin in alcohol-fed rats Am J Physiol Endocrinol Metab, June 1, 2004; 286(6): E916 - E926. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. H. Lang, R. A. Frost, N. Deshpande, V. Kumar, T. C. Vary, L. S. Jefferson, and S. R. Kimball Alcohol impairs leucine-mediated phosphorylation of 4E-BP1, S6K1, eIF4G, and mTOR in skeletal muscle Am J Physiol Endocrinol Metab, December 1, 2003; 285(6): E1205 - E1215. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |