| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Physiology, National Institute of Occupational Health, Oslo, Norway.
1. Exercise seems to change the extracellular potassium concentration far beyond the narrow limits seen in resting subjects. To examine alterations in plasma potassium concentration during exercise, twenty healthy, well-trained men ran on the treadmill at 6 deg inclination with catheters inserted in the femoral vein and artery. 2. During 1 min exhausting exercise plasma potassium concentration rose in parallel in the vein and artery, reaching peak post-exercise values of 8.34 +/- 0.23 mmol l-1 and 8.17 +/- 0.29 mmol l-1. After 3 min recovery the potassium concentration was 0.50 +/- 0.05 mmol l-1 below pre-exercise values. Both the rise of plasma potassium concentration during exercise and the decline during recovery followed exponential time courses with a half-time of 25 s. 3. Exercise at reduced intensity showed that the peak post-exercise potassium concentration was linearly related to the exercise intensity. Individual resting, peak and nadir values were proportionally related. 4. The increased potassium concentration during exercise can be explained in full by the electrical activity in the exercising muscles. Repeated 1 min exhausting exercise bouts revealed no relationship between potassium concentration and plasma pH nor glycogen break-down. 5. All of the observations fit a simple model of potassium efflux from active muscle and elimination from blood with the following characteristics: the efflux increases (decreases) stepwise at the onset (end) of exercise, and the efflux rate during exercise increases with exercise intensity. Potassium is eliminated from blood by a proportional regulator which may be the Na(+)-K+ pump of the exercising muscle. Extracellular potassium is indirectly linked to the pump stimulus, and the rate of reuptake is proportional to the extracellular accumulation. Thus no limited maximal power for potassium uptake was found. The post-exercise undershoot of 0.5 mmol l-1 can be explained by a higher gain of the pump after exercise. 6. The large, rapid changes in the plasma potassium concentration during and after exercise is due to the first order kinetics of the reuptake mechanism rather than to a limited power to take up potassium.
This article has been cited by other articles:
|
|
 |
|
  K. T. Murphy, O. B. Nielsen, and T. Clausen Analysis of exercise-induced Na+-K+ exchange in rat skeletal muscle in vivo Exp Physiol, December 1, 2008; 93(12): 1249 - 1262. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. A. Macdonald, O. B. Nielsen, and T. Clausen Effects of calcitonin gene-related peptide on rat soleus muscle excitability: mechanisms and physiological significance Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2008; 295(4): R1214 - R1223. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Clausen Clearance of Extracellular K+ during Muscle Contraction--Roles of Membrane Transport and Diffusion J. Gen. Physiol., May 1, 2008; 131(5): 473 - 481. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Nordsborg, J. Ovesen, M. Thomassen, M. Zangenberg, C. Jons, F. M. Iaia, J. J. Nielsen, and J. Bangsbo Effect of dexamethasone on skeletal muscle Na+,K+ pump subunit specific expression and K+ homeostasis during exercise in humans J. Physiol., March 1, 2008; 586(5): 1447 - 1459. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Clausen and O. B. Nielsen Potassium, Na+,K+-pumps and fatigue in rat muscle J. Physiol., October 1, 2007; 584(1): 295 - 304. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. Shushakov, C. Stubbe, A. Peuckert, V. Endeward, and N. Maassen The relationships between plasma potassium, muscle excitability and fatigue during voluntary exercise in humans Exp Physiol, July 1, 2007; 92(4): 705 - 715. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. A. Macdonald, N. Ortenblad, and O. B. Nielsen Energy conservation attenuates the loss of skeletal muscle excitability during intense contractions Am J Physiol Endocrinol Metab, March 1, 2007; 292(3): E771 - E778. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. McKenna, I. Medved, C. A. Goodman, M. J. Brown, A. R. Bjorksten, K. T. Murphy, A. C. Petersen, S. Sostaric, and X. Gong N-acetylcysteine attenuates the decline in muscle Na+,K+-pump activity and delays fatigue during prolonged exercise in humans J. Physiol., October 1, 2006; 576(1): 279 - 288. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. K. Hansen, T. Clausen, and O. B. Nielsen Effects of lactic acid and catecholamines on contractility in fast-twitch muscles exposed to hyperkalemia Am J Physiol Cell Physiol, July 1, 2005; 289(1): C104 - C112. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. R. Prabhakar and Y.-J. Peng Peripheral chemoreceptors in health and disease J Appl Physiol, January 1, 2004; 96(1): 359 - 366. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. van Lunteren and M. Moyer Wheel-running exercise alters rat diaphragm action potentials and their regulation by K+ channels J Appl Physiol, August 1, 2003; 95(2): 602 - 610. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Nordsborg, M. Mohr, L. D. Pedersen, J. J. Nielsen, H. Langberg, and J. Bangsbo Muscle interstitial potassium kinetics during intense exhaustive exercise: effect of previous arm exercise Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2003; 285(1): R143 - R148. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Yensen, W. Matar, and J.-M. Renaud K+-induced twitch potentiation is not due to longer action potential Am J Physiol Cell Physiol, July 1, 2002; 283(1): C169 - C177. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 O. M. Sejersted and G. Sjogaard Dynamics and Consequences of Potassium Shifts in Skeletal Muscle and Heart During Exercise Physiol Rev, October 1, 2000; 80(4): 1411 - 1481. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. I. Lindinger, P. L. Horn, and S. P. Grudzien Exercise-induced stimulation of K+ transport in human erythrocytes J Appl Physiol, December 1, 1999; 87(6): 2157 - 2167. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. E. Martynyuk, T. E. Morey, L. Belardinelli, and D. M. Dennis Hyperkalemia Enhances the Effect of Adenosine on IK,ADO in Rabbit Isolated AV Nodal Myocytes and on AV Nodal Conduction in Guinea Pig Isolated Heart Circulation, January 19, 1999; 99(2): 312 - 318. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Maassen, M. Foerster, and H. Mairbaurl Red blood cells do not contribute to removal of K+ released from exhaustively working forearm muscle J Appl Physiol, July 1, 1998; 85(1): 326 - 332. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Hardarson, J. O. Skarphedinsson, and T. Sveinsson Importance of the lactate anion in control of breathing J Appl Physiol, February 1, 1998; 84(2): 411 - 416. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Wasserman, W. W. Stringer, R. Casaburi, and Y.-Y. Zhang Mechanism of the exercise hyperkalemia: an alternate hypothesis J Appl Physiol, August 1, 1997; 83(2): 631 - 643. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. O'Neill, C. E. Sears, and D. J. Paterson Interactive effects of K+, acid, norepinephrine, and ischemia on the heart: implications for exercise J Appl Physiol, April 1, 1997; 82(4): 1046 - 1052. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
