Reversibility of exercise-induced translocation of Na+-K+ pump subunits to the plasma membrane in rat skeletal muscle
Research output: Contribution to journal › Journal article
Exercise-induced translocation of Na+-K+ pump subunits to the sarcolemmal membrane was studied using sarcolemmal giant vesicles as a membrane purification procedure. The subunit content was quantified by Western blotting or by ouabain labeling. Low-intensity treadmill running increased (P<0.01) the alpha1, alpha2, beta1, and beta2 subunit contents by 19-32% in membranes from oxidative muscle fibers and the alpha1, alpha2, and beta2 contents increased by 13-25% in membranes from glycolytic muscle fibers. Ouabain labeling of membranes from mixed fibers was increased by 29% after exercise. A similar increase in subunit content could be induced by 5 min of fatiguing, high-intensity electrical stimulation of isolated soleus muscles. An increased subunit content was just detectable in vesicles produced 30 min after exercise, and the content was completely back to control levels 3 h after exercise. It is concluded that both low-intensity long-lasting running and short-lasting high-intensity contractions are able to induce a translocation of pump subunits to the sarcolemmal membrane. The post-exercise disappearance of the extra subunits (half-time approximately 20 min) from the membrane demonstrates the reversible nature of the translocation process.
|Journal||Pflügers Archiv - European Journal of Physiology|
|Number of pages||6|
|Publication status||Published - Nov 2001|
- Animals, Biological Transport, Cell Membrane/metabolism, Electric Stimulation, Glycolysis, Male, Motor Activity/physiology, Muscle, Skeletal/metabolism, Ouabain/metabolism, Oxidation-Reduction, Rats, Rats, Wistar, Sodium-Potassium-Exchanging ATPase/metabolism, Time Factors