Short-term exercise enhances insulin-stimulated GLUT-4 translocation and glucose transport in adipose cells.
This investigation examined the effects of short-term exercise training on insulin-stimulated GLUT-4 glucose transporter translocation and glucose transport activity in rat adipose cells. Male Wistar rats were randomly assigned to a sedentary (Sed) or swim training group (Sw, 4 days; final 3 days: 2 x 3 h/day). Adipose cell size decreased significantly but minimally (approximately 20%), whereas total GLUT-4 increased by 30% in Sw vs. Sed rats. Basal 3-O-methyl-D-[14C]glucose transport was reduced by 62%, whereas maximally insulin-stimulated (MIS) glucose transport was increased by 36% in Sw vs. Sed rats. MIS cell surface GLUT-4 photolabeling was 44% higher in the Sw vs. Sed animals, similar to the increases observed in MIS glucose transport activity and total GLUT-4. These results suggest that increases in total GLUT-4 and GLUT-4 translocation to the cell surface contribute to the increase in MIS glucose transport with short-term exercise training. In addition, the results suggest that the exercise training-induced adaptations in glucose transport occur more rapidly than previously thought and with minimal changes in adipose cell size.
Ferrara
C M
CM
Experimental Diabetes, Metabolism, and Nutrition Section, Diabetes Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, USA.
Reynolds
T H
TH
Zarnowski
M J
MJ
Brozinick
J T
JT
Cushman
S W
SW
D000273:Adipose Tissue / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D005947:Glucose / Q000378:metabolism*; D051272:Glucose Transporter Type 1; D051275:Glucose Transporter Type 4; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D009124:Muscle Proteins; D010805:Physical Conditioning, Animal / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013550:Swimming / Q000502:physiology
D051272:Glucose Transporter Type 1; D051275:Glucose Transporter Type 4; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; C495694:Slc2a4 protein, rat; D005947:Glucose