No evidence of direct association between GLUT4 and glycogen in human skeletal muscle
Journal article
Murphy, Robyn M., Flores-Opazo, Marcelo, Frankish, Barnaby P., Garnham, Andrew, Stapleton, David and Hargreaves, Mark. (2018). No evidence of direct association between GLUT4 and glycogen in human skeletal muscle. Physiological Reports. 6(21), pp. 1 - 5. https://doi.org/10.14814/phy2.13917
Authors | Murphy, Robyn M., Flores-Opazo, Marcelo, Frankish, Barnaby P., Garnham, Andrew, Stapleton, David and Hargreaves, Mark |
---|---|
Abstract | Previous studies have demonstrated that exercise increases whole body and skeletal muscle insulin sensitivity that is linked with increased GLUT4 at the plasma membrane following insulin stimulation and associated with muscle glycogen depletion. To assess the potential direct association between muscle glycogen and GLUT4, seven untrained, male subjects exercised for 60 min at ~75% VO2 peak, with muscle samples obtained by percutaneous needle biopsy immediately before and after exercise. Exercise reduced muscle glycogen content by ~43%. An ultracentrifugation protocol resulted in a ~2‐3‐fold enriched glycogen fraction from muscle samples for analysis. Total GLUT4 content was unaltered by exercise and we were unable to detect any GLUT4 in glycogen fractions, either with or without amylase treatment. In skinned muscle fiber segments, there was very little, if any, GLUT4 detected in wash solutions, except following exposure to 1% Triton X‐100. Amylase treatment of single fibers did not increase GLUT4 in the wash solution and there were no differences in GLUT4 content between fibers obtained before or after exercise for any of the wash treatments. Our results indicate no direct association between GLUT4 and glycogen in human skeletal muscle, before or after exercise, and suggest that alterations in GLUT4 translocation associated with exercise‐induced muscle glycogen depletion are mediated via other mechanisms. |
Keywords | GLUT4; Glycogen; skeletal muscle |
Year | 2018 |
Journal | Physiological Reports |
Journal citation | 6 (21), pp. 1 - 5 |
Publisher | John Wiley & Sons |
ISSN | 2051-817X |
Digital Object Identifier (DOI) | https://doi.org/10.14814/phy2.13917 |
Scopus EID | 2-s2.0-85057440089 |
Open access | Open access |
Page range | 1 - 5 |
Research Group | Mary MacKillop Institute for Health Research |
Publisher's version | License |
Place of publication | United Kingdom |
Editors | T. Kleyman |
https://acuresearchbank.acu.edu.au/item/899yz/no-evidence-of-direct-association-between-glut4-and-glycogen-in-human-skeletal-muscle
Download files
109
total views80
total downloads0
views this month0
downloads this month