| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Muscle, Ions and Exercise Group, School of Human Movement, Recreation and Performance, Centre for Aging, Rehabilitation, Exercise and Sport Science (CARES), Victoria University of Technology, Melbourne, Victoria, Australia
2 Exercise, Muscle and Metabolism Unit, School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Victoria, Australia
* To whom correspondence should be addressed. E-mail: michael.mckenna{at}vu.edu.au.
This study investigated effects of prolonged submaximal exercise on Na+,K+-ATPase mRNA and protein expression, maximal activity and content in human skeletal muscle. We also investigated the effects on mRNA expression of the transcription initiator gene, RNAP II, and key genes involved in protein translation, eIF-4E and 4E-BP1. Eleven subjects (six males, five females) cycled at 75.5 (SD 4.8)% peak O2 uptake (mean (SD)), continued until fatigue. A vastus lateralis muscle biopsy was taken at rest, fatigue, 3 and 24 h post-exercise. Muscle was analyzed for Na+,K+-ATPase 
1, 2, 3, 
1, 2 and 3, as well RNAP II, eIF-4E and 4E-BP1 mRNA expression by Real-Time RT-PCR and Na+,K+-ATPase isoform protein abundance using immunoblotting. Muscle homogenate maximal Na+,K+-ATPase activity was determined by 3-O-MFPase activity and Na+,K+-ATPase content by [3H]-ouabain binding. Cycling to fatigue (54.5 (SD 20.6) min) immediately increased 3 (P=0.044) and 2 mRNA (P=0.042) by 2.2- and 1.9-fold, respectively, whilst 1 mRNA was elevated by 2.0-fold at 24 h post-exercise (P=0.036). A significant time main effect was found for 3 protein abundance (P=0.046). Exercise transiently depressed maximal Na+,K+-ATPase activity (P=0.004), but Na+,K+-ATPase content was unaltered throughout recovery. Exercise immediately increased RNAP II mRNA by 2.6-fold (P=0.011), but had no effect on eIF-4E and 4E-BP1 mRNA. Thus, a single bout of prolonged submaximal exercise induced isoform-specific
Na+,K+-ATPase responses, increasing 1, 3 and 2 mRNA but only 3 protein expression. Exercise also increased mRNA expression of RNAP II, a gene initiating transcription, but not of eIF-4E and 4E-BP1, key genes initiating protein translation.
This article has been cited by other articles:
|
|
 |
|
  H. J. Green, T. A. Duhamel, R. D. Stewart, A. R. Tupling, and J. Ouyang Dissociation between changes in muscle Na+-K+-ATPase isoform abundance and activity with consecutive days of exercise and recovery Am J Physiol Endocrinol Metab, April 1, 2008; 294(4): E761 - E767. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. J. McKenna, J. Bangsbo, and J.-M. Renaud Muscle K+, Na+, and Cl disturbances and Na+-K+ pump inactivation: implications for fatigue J Appl Physiol, January 1, 2008; 104(1): 288 - 295. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. J. Green, T. A. Duhamel, G. P. Holloway, J. W. Moule, J. Ouyang, D. Ranney, and A. R. Tupling Muscle Na+-K+-ATPase response during 16 h of heavy intermittent cycle exercise Am J Physiol Endocrinol Metab, August 1, 2007; 293(2): E523 - E530. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. J. Aughey, K. T. Murphy, S. A. Clark, A. P. Garnham, R. J. Snow, D. Cameron-Smith, J. A. Hawley, and M. J. McKenna Muscle Na+-K+-ATPase activity and isoform adaptations to intense interval exercise and training in well-trained athletes J Appl Physiol, July 1, 2007; 103(1): 39 - 47. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. T. Murphy, W. A. Macdonald, M. J. McKenna, and T. Clausen Ionic mechanisms of excitation-induced regulation of Na+-K+-ATPase mRNA expression in isolated rat EDL muscle Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2006; 290(5): R1397 - R1406. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
