Effects of ovariectomy and exercise training on muscle GLUT-4 content and glucose metabolism in rats.
The present study examined the effects of 6 wk of ovarian endocrine deficiency on skeletal muscle GLUT-4 glucose transporter protein and glucose transport activity in sedentary and endurance-trained rats. Female Wistar rats (10 wk old) underwent bilateral ovariectomy (OVX) or sham surgery followed by a 5-wk swim-training protocol. OVX resulted in no significant changes in glycogen or GLUT-4 glucose transporter concentration in the soleus, epitrochlearis, or flexor digitorum brevis (FDB) muscles or in basal and maximally insulin-stimulated 2-deoxy-D-[1,2-3H]glucose (2-[3H]DG) transport in the soleus or epitrochlearis, suggesting that moderate-duration ovarian hormone deficiency does not significantly impair insulin action in skeletal muscle. In contrast, OVX decreased the maximal activation of 2-[3H]DG transport in the FDB by in vitro electrical stimulation. OVX had no significant effect on the training-induced changes in oxidative enzyme activities, GLUT-4 protein expression, glycogen content, or insulin-stimulated 2-[3H]DG transport in the soleus or epitrochlearis. These findings provide the first evidence that ovarian hormone deficiency decreases contraction-stimulated glucose transport in skeletal muscle.
Hansen
P A
PA
Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
McCarthy
T J
TJ
Pasia
E N
EN
Spina
R J
RJ
Gulve
E A
EA
D000818:Animals; D005260:Female; D005947:Glucose / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D010052:Ovariectomy; D010805:Physical Conditioning, Animal; D051381:Rats; D017208:Rats, Wistar
D007328:Insulin; D009004:Monosaccharide Transport Proteins; D005947:Glucose