Effects of ovariectomy and exercise training on muscle glut4
content and glucose metabolism in rats.
Hansen, Polly A., Thomas J. McCarthy, E. Neil Pasia, Robert J. Spina,
and Eric A. Gulve.
Department of Internal Medicine and Division of Comparative
Medicine, Washington University School of Medicine, St. Louis, MO
63110
APStracts 2:0550A, 1995.
The present study examined the effects of 6 weeks of ovarian endocrine
deficiency on skeletal muscle GLUT4 glucose transporter protein and
glucose transport activity in sedentary and endurance trained rats.
Female Wistar rats (10 weeks old) underwent bilateral ovariectomy
(OVX) or sham surgery, followed by a five-week swim training
protocol. OVX resulted in no significant changes in glycogen or GLUT4
glucose transporter concentration in the soleus (SOL), epitrochlearis
(EPI) or flexor digitorum brevis (FDB) muscles, or basal and
maximally insulin-stimulated 2-deoxy-D-[1,2-3H]glucose (2DG)
transport in SOL or EPI, suggesting that moderate duration ovarian
hormone deficiency does not significantly impair insulin action in
skeletal muscle. In contrast, OVX decreased the maximal activation of
2DG transport in the FDB by in vitro electrical stimulation. OVX had
no significant effect on the training-induced changes in oxidative
enzyme activities, GLUT4 protein expression, glycogen content or
insulin-stimulated 2DG transport in the SOL or EPI. These findings
provide the first evidence that ovarian hormone deficiency decreases
contraction-stimulated glucose transport in skeletal muscle.
Received 12 July 1995; accepted in final form 5 December 1995.
APS Manuscript Number A757-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 December 95