Glucose, exercise and insulin: emerging concepts.
Physical exercise induces a rapid increase in the rate of glucose uptake in the contracting skeletal muscles. The enhanced membrane glucose transport capacity is caused by a recruitment of glucose transporters (GLUT4) to the sarcolemma and t-tubules. This review summarises the recent progress in the understanding of signals that trigger GLUT4 translocation in contracting muscle. The possible involvement of calcium, protein kinase C (PKC), nitric oxide (NO), glycogen and AMP-activated protein kinase (AMPK) are discussed. Furthermore, the possible mechanisms behind the well-described improvement of insulin action on glucose uptake and glycogen synthase activity in the post-exercise period is discussed. It is concluded that both during and following muscle contractions, glycogen emerges as an important modulator of signalling events in glucose metabolism.
Richter
E A
EA
Copenhagen Muscle Research Centre, Department of Human Physiology, Institute of Exercise and Sports Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark. erichter@aki.ku.dk
Derave
W
W
Wojtaszewski
J F
JF
D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D005082:Physical Exertion / Q000502:physiology*
D007328:Insulin; D005947:Glucose