Skeletal muscle GLUT-4 and glucose uptake during exercise in humans

Abstract

The present study examined the relationship between total skeletal muscle GLUT-4 protein level and glucose uptake during exercise. Eight active non- endurance-trained men cycled at 72 ± 1% peak pulmonary oxygen consumption for 40 min, with rates of glucose appearance and disappearance (Rd) determined by utilizing a primed continuous infusion of [3-3H]glucose commencing 2 h before exercise. Muscle glycogen content and utilization, citrate synthase activity, and total GLUT-4 protein were measured on muscle biopsy samples obtained from the vastus lateralis. A direct relationship existed between preexercise muscle glycogen content and glycogen utilization during exercise (r = 0.76, P < 0.05). Ci..