Exercise signalling to glucose transport in skeletal muscle.
Contraction-induced glucose uptake in skeletal muscle is mediated by an insulin-independent mechanism that leads to translocation of the GLUT4 glucose transporter to the muscle surface membrane from an intracellular storage site. Although the signalling events that increase glucose transport in response to muscle contraction are not fully elucidated, the aim of the present review is to briefly present the current understanding of the molecular signalling mechanisms involved. Glucose uptake may be regulated by Ca(2+)-sensitive contraction-related mechanisms, possibly involving Ca(2+)/calmodulin-dependent protein kinase II and some isoforms of protein kinase C. In addition, glucose transport may be regulated by mechanisms that reflect the metabolic status of the muscle, probably involving the 5'AMP-activated protein kinase. Furthermore, the p38 mitogen-activated protein kinase may be involved in activating the GLUT4 translocated to the surface membrane. Nevertheless, the picture is incomplete, and fibre type differences also seem to be involved.
Copenhagen Muscle Research Centre, Department of Human Physiology, Institute of Exercise and Sport Sciences, University of Copenhagen, Universitetsparken 13, 2100 Copenhagen Ø, Denmark. erichter@ak.ku.dk
Erik A
EA
Richter
Jakob N
JN
Nielsen
Sebastian B
SB
Jørgensen
Christian
C
Frøsig
Jesper B
JB
Birk
Jørgen F P
JF
Wojtaszewski
D000263:Adenylate Kinase / Q000378:metabolism; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009097:Multienzyme Complexes / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
D009097:Multienzyme Complexes; D020928:Mitogen-Activated Protein Kinases; D000263:Adenylate Kinase; D005947:Glucose; D002118:Calcium