Skeletal muscle glut4 and post-exercise muscle glycogen storage in
humans.
Proietto*, Michael McCoy Joseph, and Mark Hargreaves.
Departments of Physiology and Medicine (Royal Melbourne Hospital),
The University of Melbourne, Parkville, Victoria, 3052, Australia
APStracts 2:0420A, 1995.
The purpose of this study was to examine the relationship between
skeletal muscle GLUT4 protein and post-exercise glycogen storage in
human subjects fed adequate carbohydrate. Eleven men completed 2 h of
cycling, a biopsy of the vastus lateralis being performed immediately
after exercise cessation for determination of muscle GLUT4 protein
and glycogen concentration, glycogen synthase activity and citrate
synthase activity. Subjects ingested meals providing 2.0 g
carbohydrate per kg body weight at 0, 2 and 4 h post-exercise, a
second biopsy being performed 6 h post-exercise. Muscle glycogen
concentration increased significantly (p<0.05) during the 6 h
recovery period (immediately post-exercise: Gly0 = 27.2 + 5.4 mmol/kg
wet weight, DGly = 52.4 + 2.9 mmol/kg ww.6h). Glycogen storage during
recovery was directly related (r = 0.63, p<0.05) to GLUT4
protein (2.20 + 0.33 arb. std. units) and inversely related (r =
-0.70, p<0.05) to Gly0. A direct correlation existed between
glycogen storage during recovery and the activity of the I form of
glycogen synthase (r = 0.60, p<0.05). These results suggest that
muscle GLUT4 protein concentration, as well as factors relating to
glucose disposal, may affect post-exercise glycogen storage in humans
fed adequate carbohydrate.
Received 2 March 1995; accepted in final form 7 September 1995.
APS Manuscript Number A234-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95