Regulation of Na+/K+ pump activity and importance of skeletal muscle ion transporting proteins for performance in humans
PhD thesis by Martin Thomassen
2010, 160 pages, DKR 100,-
ISBN: 978 87 917 71 255
Development of muscular fatigue in human skeletal muscles during exercise is a complex phenomenon. Disturbances in ion homeostasis around the muscle membrane and particular accumulation of K+ in the interstitium can induce membrane depolarization and thereby affect the ability to perform intense work. Thus, the expression of the ion transporting proteins in skeletal muscles seems to be of importance for human muscle cells in order to control ion homeostasis and postpone development of muscle fatigue in relation to intense exercise.
The present PhD thesis has primarily focused on interventions able to manipulate with the expression of proteins involved in ion regulation. Treatment with dexamethasone as well as different training and inactivity regimes has been successfully used for this purpose. Effects of ion regulation during intense exercise on muscle fatigue development and exercise performance has been examined. Furthermore, molecular mechanisms involved in the regulation of Na+/K+ pump activity in the transition from rest to exercise is addressed in the thesis.
Results from the included experiments show a connection between alterations in FXYD1 phosphorylation and the exercise induced increase in human skeletal muscle Na+/K+ pump activity. As well, changes in the expression of proteins involved in ion transport across muscle membranes and especially K+ regulation seems to affect performance of intense exercise.
Contents (pdf, 184 KB)
Summary (pdf, 133 KB)
Preface (pdf, 144 KB)