Letter | Published:

K-contractures and membrane potential in mammalian skeletal muscle

Nature volume 266, pages 7578 (03 March 1977) | Download Citation

Subjects

Abstract

A FUNDAMENTAL property of skeletal muscle fibres is the ability to develop tension in response to surface membrane depolarisation. The relation between membrane potential (Vm) and tension has been measured in amphibian muscle using external potassium concentration (K0) to clamp Vm 1–4. A K-contracture follows exposure to high K0 and tension is graded with K0 between 20 mM (Vm = −50 mV) and 50 mM (Vm= −40 mV). Human intercostal muscle, however, either does not respond mechanically to K0 of 80 mM or gives a very small contracture5. It is not clear whether this is a result of diffusion delays in the large bundles of fibres or whether there is a basic species difference in excitation–contraction coupling. I report here that, in bundles of fewer than 20 fibres, the relationship between K-contracture tension and K0 is shifted to higher K0 in rat muscle because changes in K0 are less effective in altering Vm.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    & J. Physiol. Lond. 153, 386–403 (1960).

  2. 2.

    J. Physiol. Lond. 223, 461–482 (1972).

  3. 3.

    J. Physiol. Lond. 223, 485–505 (1972).

  4. 4.

    J. gen. Physiol. 58, 117–130 (1971).

  5. 5.

    & Clin. exp. Pharmac. Physiol. 1, 197–209 (1974).

  6. 6.

    Proc. Aust. Physiol. Pharmacol. Soc. 7, 3P (1976).

  7. 7.

    & J. Physiol Lond. 234, 373–408 (1973).

  8. 8.

    , & J. Cell Biol. 47, 107–119 (1970).

  9. 9.

    & Am. J. Physiol. 222, 1435–1439 (1972).

  10. 10.

    & J. gen. Physiol. 61, 158–175 (1973a).

  11. 11.

    & J. gen. Physiol. 62, 737–755 (1963).

  12. 12.

    , & J. Physiol. Lond. 204, 207–230 (1969).

  13. 13.

    J. gen. Physiol. 63, 657–674 (1974).

  14. 14.

    & J. gen. Physiol. 50, 89–113 (1966).

  15. 15.

    & Am. J. Physiol. 208, 1042–1045 (1965).

  16. 16.

    J. Physiol. Lond. 170, 227–237 (1964).

  17. 17.

    J. Physiol. Lond. 169, 690–705 (1963).

  18. 18.

    J. Physiol. Lond. 225, 57 (1972).

  19. 19.

    & J. Membrane Biol. 14, 243–292 (1973).

  20. 20.

    & J. Physiol. Lond. 148, 127–160 (1959).

Download references

Author information

Author notes

    • ANGELA DULHUNTY

    Present address: Department of Anatomy, University of Sydney, New South Wales 2006, Australia.

Affiliations

  1. New South Wales Institute of Technology, School of Life Sciences, Gore Hill, New South Wales, Australia

    • ANGELA DULHUNTY

Authors

  1. Search for ANGELA DULHUNTY in:

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/266075a0

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.