Advertisement

The Journal of Membrane Biology

, Volume 91, Issue 2, pp 165–172 | Cite as

Effects of external K concentration on the electrogenicity of the insulin-stimulated Na,K-pump in frog skeletal muscle

  • Yoshinori Marunaka
Articles

Summary

Insulin hyperpolarized the membrane of frog skeletal muscle by stimulating the electrogenic Na,K-pump. At external K concentrations of 1, 2, 5 and 10mm, both the insulin-induced hyperpolarization and the insulin-stimulated ouabain-sensitive Na efflux (an index of Na, K-pump activity) were observed. By increasing the external K concentration, the insulin-stimulated Na efflux increased, but the magnitude of the insulin-induced hyperpolarization decreased; i. e., although the activity of the insulin-stimulated Na,K-pump increased, on the contrary, the magnitude of the hyperpolarization decreased. To clarify the causes of this phenomenon, the specific membrane resistance was measured and found to decrease upon increasing the external K concentration.

One of the reasons for the decrease in magnitude of the hyperpolarization is the decrease in the specific membrane resistance. However, the decrease in magnitude of the hyperpolarization with a rise of the external K concentration, which increased the insulin-stimulated Na,K-pump activity, cannot be explained only by the decrease in the specific membrane resistance. It is suggested that the decrease in magnitude of the hyperpolarization is mainly caused by a decrease in the electrogenicity of the insulin-stimulated Na,K-pump upon an increase in the external K concentration. The conclusion of the present study is that the electrogenicity of the insulin-stimulated Na,K-pump in muscles is variable and decreases with increasing the external K concentration.

Key Words

membrane potential Na,K-pump electrogenicty membrane resistance insulin external K skeletal muscle 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Beaugé, L.A., Sjodin, R.A. 1976. An analysis of the influence of membrane potential and metabolic poisoning with azide on the sodium pump in skeletal muscle.J. Physiol. (London) 263:383–403Google Scholar
  2. Beaugé, L.A., Sjodin, R.A., Ortiz, O. 1975. The independence of membrane potential and potassium activiation of the sodium pump in muscle.Biochim. Biophys. Acta 389:189–193PubMedGoogle Scholar
  3. Brinley, F.J., Mullins, L.J. 1974. Effects of membrane potential on sodium and potassium fluxes in squid axons.Ann. N.Y. Acad. Sci. 242:406–433PubMedGoogle Scholar
  4. Eisner, D.A., Lederer, W.J., Vaughan-Jones, R.D. 1981. The dependence of sodium pumping and tension on intracellular sodium activity in voltage-clamped sheep purkinje fibres.J. Physiol. (London) 317:163–187Google Scholar
  5. Gardos, G. 1964. Concentration between membrane adenosinetriphosphatase activity and potassium transport in erythrocyte ghosts.Experientia 20:387PubMedGoogle Scholar
  6. Hodgkin, A.L., Keynes, R.D. 1955. Active transport of cations in giant axons fromSepia andLoligo.J. Physiol. (London) 128:28–60Google Scholar
  7. Jenerick, H.P. 1953. Muscle membrane potential, resistance, and external potassium chloride.J. Cell. Comp. Physiol. 42:427–448CrossRefGoogle Scholar
  8. Keynes, R.D. 1965. Some further observations on the sodium efflux in frog muscle.J. Physiol. (London) 178:305–325Google Scholar
  9. Keynes, R.D., Steinhardt, R.A. 1968. The components of the sodium efflux in frog muscle.J. Physiol. (London) 198:581–599Google Scholar
  10. Keynes, R.D., Swan, R.C. 1959. The effect of external sodium concentration on the sodium fluxes in frog skeletal muscle.J. Physiol. (London) 147:591–625Google Scholar
  11. Kitasato, H., Marunaka, Y., Murayama, K., Nishio, K. 1980a. Insulin-sensitive Na efflux and the extracellular K concentration. Proceedings of the 18th annual meeting of Biophysical Society of Japan.P. 203 (in Japanese)Google Scholar
  12. Kitasato, H., Sato, S., Marunaka, Y., Murayama, K., Nishio, K. 1980b. Effects of ouabain on Na efflux in high internal Na and insulin-preincubated muscles.Jpn. J. Physiol. 30:591–602PubMedGoogle Scholar
  13. Kitasato, H., Sato, S., Murayama, K., Nishio, K. 1980c. The interaction between the effects of insulin and ouabain on the activity of Na transport system in frog skeletal muscle.Jpn. J. Physiol. 30:115–130PubMedGoogle Scholar
  14. Kitasato, H., Sato, S., Marunaka, Y., Murayama, K., Nishio, K. 1980d. Apparent affinity changes induced by insulin of Na−K transport system in frog skeletal muscle.Jpn. J. Physiol. 30:606–616Google Scholar
  15. Lederer, W.J., Nelson, M.T. 1984. Sodium pump stoichiometry determined by simulataneous measurements of sodium efflux and membrane current in barnacle.J. Physiol. (London) 348:665–677Google Scholar
  16. Marunaka, Y., Kitasato, H. 1985. The sensitivity of the insulin-stimulated ouabain-sensitive Na efflux from frog sartorius muscle to internal Na, external K and ouabain.IRCS Med. Sci. 13:445–446Google Scholar
  17. Moore, R.D., Rabovsky, J.L. 1979. Mechanism of insulin action on resting membrane potential of frog skeletal muscle.Am. J. Physiol. 236:C249-C254PubMedGoogle Scholar
  18. Mullins, L.J., Brinley, F.J. 1969. Potassium fluxes in dialyzed squid axons.J. Gen. Physiol. 53:704–740CrossRefPubMedGoogle Scholar
  19. Mullins, L.J., Frumento, A.S. 1963. The concentration dependence of sodium efflux from muscle.J. Gen. Physiol. 46:629–654CrossRefPubMedGoogle Scholar
  20. Mullins, L.J., Noda, K. 1963. The influence of sodium-free solutions on the membrane potential of frog muscle fibres.J. Gen. Physiol. 47:117–132PubMedGoogle Scholar
  21. Post, R.L., Albright, C.D., Dayani, K. 1967. Resolution of pump and leak components of sodium and potassium ion transport in human erythrocytes.J. Gen. Physiol. 50:1201–1220CrossRefPubMedGoogle Scholar
  22. Sen, A.K., Post, R.L. 1964. Stoichiometry and localization of adenosine triphosphatase dependent sodium and potassium transport in the erythrocyte.J. Biol. Chem. 239:345–352PubMedGoogle Scholar
  23. Sjodin, R.A., Beaugé, L.A. 1967. The ion selectivity and concentration dependence of cation coupled active sodium transport in squid axon.Curr. Mod. Biol. 1:105–115PubMedGoogle Scholar
  24. Sjodin, R.A., Henderson, E.G. 1964. Tracer and non-tracer potassium fluxes in frog sartorius muscle and the kinetics of net potassium movement.J. Gen. Physiol. 47:605–638CrossRefPubMedGoogle Scholar
  25. Whittam, R., Ager, M.E. 1965. The connection between active transport and metabolism in erythrocytes.Biochem. J. 97:214–227Google Scholar
  26. Zierler, K.L. 1957. Increase in resting membrane potential of skeletal muscle produced by insulin.Science 126:1067–1068PubMedGoogle Scholar
  27. Zierler, K.L. 1959. Effect of insulin on membrane potential and potassium content of rat muscle.Am. J. Physiol. 197:515–523PubMedGoogle Scholar

Copyright information

© Springer-Verlag New York Inc. 1986

Authors and Affiliations

  • Yoshinori Marunaka
    • 1
  1. 1.Department of PhysiologyShiga University of Medical ScienceOhtsuJapan

Personalised recommendations