Pflügers Archiv

, Volume 362, Issue 1, pp 85–94

Work-induced potassium changes in skeletal muscle and effluent venous blood assessed by liquid ion-exchanger microelectrodes


  • P. Hník
    • Institute of PhysiologyCzechoslovak Academy of Sciences
  • M. Holas
    • Institute of PhysiologyCzechoslovak Academy of Sciences
  • I. Krekule
    • Institute of PhysiologyCzechoslovak Academy of Sciences
  • N. Kříž
    • Institute of PhysiologyCzechoslovak Academy of Sciences
  • J. Mejsnar
    • Department of ZoologyCharles University
  • V. Smieško
    • Institute of Normal and Pathological PhysiologySlovak Academy of Sciences
  • E. Ujec
    • Institute of PhysiologyCzechoslovak Academy of Sciences
  • F. Vyskočil
    • Institute of PhysiologyCzechoslovak Academy of Sciences

DOI: 10.1007/BF00588685

Cite this article as:
Hník, P., Holas, M., Krekule, I. et al. Pflugers Arch. (1976) 362: 85. doi:10.1007/BF00588685


Using liquid ion-exchanger semimicroelectrodes with a side pore, we measured changes of extracellular potassium concentration (Ke+) in adult rabbit and cat gastrocnemius muscles and in venous effluent blood flowing from the cat gastrocnemius muscle during various bouts of activity induced by sciatic nerve stimulation.
  1. 1.

    Isometric tetanic contractions (at 50 Hz) of various durations caused transient accumulation of Ke+ which was non-linearly related to the duration of muscle activity. The peak values of Ke+ in response to muscle stimulation were analogous in rabbits and cats, attaining values, e.g. after a 20-s isometric tetanus, between 8–9 mEq/lK+ in both species.

  2. 2.

    Potassium concentration in venous effluent blood (Kven+) was transiently increased after isometric tetani. Since blood flow was measured at the same time, it was possible to calculate the amount of K+ lost by the muscle after tetani of various durations. A 32 g gastrocnemius muscle of the cat, for example, loses 9.36±1.52 μEqK+ after a 20-s isometric tetanus, which corresponds roughly to 0.5% of the total muscle potassium content. The loss of K+ in this muscle was 29.3 pEq K+/impulse/100 g fresh muscle tissue.

  3. 3.

    There was no evident difference between the amount of K+ released during isometric tetani, or tetanic contractions performed under isotonic conditions. Single twitches evoked by indirect stimulation at 1 Hz for several minutes also induced a small rise in Kven+.

  4. 4.

    If the loss of K+ from the muscle into the blood stream is transiently prevented by arterio-venous occlusion installed immediately before a 10-s isometric tetanus, most K+ is released subsequently when blood flow is renewed, if the occlusion lasts for 20–25 s. It is not until blood flow is occluded for 40–60 s that most K+ is apparently resorbed and only a minor portion is released and is to be found in the venous blood.

  5. 5.

    The transient accumulation of muscle extracellular potassium may locally affect nerve endings, skeletal and smooth muscle cells.


Key words

Ion-exchanger microelectrodesMuscle potassium effluxWork-induced changes in muscleWork-induced changes in venous bloodMuscle work

Copyright information

© Springer-Verlag 1976