Glucose uptake in muscle cell cultures from endurance-trained men

Purpose: 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 approximate to 1.5-fold over basal. In relation to exercise training status, basal glucose uptake was significantly (P < 0.05) elevated by approximate to 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 eta M, although the relative increase in insulin-mediated glucose uptake (fold increase over basal) did not differ between the sedentary and endurance-trained cells.