Glucose uptake in muscle cell cultures from endurance-trained men.
OBJECTIVE
To examine noninsulin- (basal) and insulin-mediated glucose uptake in human skeletal muscle cells from endurance-trained and sedentary individuals.


METHODS
Muscle biopsies (vastus lateralis) were obtained from competitive, endurance-trained athletes (N=12; VO2peak 64.9+/-2.3 mL.kg-1.min-1) and their sedentary counterparts (N=8; VO2peak 51.8+/-2.2 mL.kg-1.min-1), and isolated satellite cells allowed to proceed to myotubes.


RESULTS
The myotubes exhibited a dose response for glucose uptake with increasing insulin concentrations; maximal glucose uptake was approximately 1.5-fold over basal. In relation to exercise training status, basal glucose uptake was significantly (P<0.05) elevated by approximately 75% in the endurance-trained versus sedentary men (20.1+/-2.1 vs 11.9+/-1.9 pmol.mg protein-1.min-1, respectively). This difference persisted at insulin concentrations of 10 and 1000 etaM, although the relative increase in insulin-mediated glucose uptake (fold increase over basal) did not differ between the sedentary and endurance-trained cells.


CONCLUSIONS
These data suggest that cultured skeletal muscle cells from endurance-trained athletes may differ in respect to basal glucose uptake.
Berggren
Jason R
JR
Human Performance Laboratory, Department of Exercise & Sport Science, and Diabetes/Obesity Center, East Carolina University, Greenville, NC 27858, USA. berggrenj@mail.ecu.edu
Tanner
Charles J
CJ
Koves
Timothy R
TR
Muoio
Deborah M
DM
Houmard
Joseph A
JA
D000328:Adult; D000704:Analysis of Variance; D018929:Cell Culture Techniques / Q000379:methods; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008019:Life Style; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D013177:Sports / Q000502:physiology
D005947:Glucose