The Journal of Membrane Biology

, Volume 22, Issue 1, pp 285–312 | Cite as

Sodium-calcium exchange and calcium-calcium exchange in internally dialyzed squid giant axons

  • M. P. Blaustein
  • J. M. Russell


The influx and efflux of calcium (as45Ca) and influx of sodium (as24Na) were studied in internally dialyzed squid giant axons. The axons were poisoned with cyanide and ATP was omitted from the dialysis fluid. The internal ionized Ca2+ concentration ([Ca2+] i ) was controlled with Ca-EGTA buffers. With [Ca2+] i >0.5 μm,45Ca efflux was largely dependent upon external Na and Ca. The Na 0 -dependent Ca efflux into Ca-free media appeared to saturate as [Ca2+] i was increased to 160 μm; the half-saturation concentration was about 8 μm Ca2+. In two experiments24Na influx was measured; when [Ca2+] i was decreased from 160 μm to less than 0.5 μm, Na influx declined by about 5 pmoles/cm2 sec. The Na 0 -dependent Ca efflux averaged 1.6 pmoles/cm2 sec in axons with a [Ca2+] i of 160 μm, and was negligible in axons with a [Ca2+] i of less than 0.5 μm. Taken together, the Na influx and Ca efflux data may indicate that the fluxes are coupled with a stoichiometry of about 3 Na+-to-1 Ca2+. Ca efflux into Na-free media required the presence of both Ca and an alkali metal ion (but not Cs) in the external medium. Ca influx from Li-containing media was greatly reduced when [Ca2+] i was decreased from 160 to 0.23 μm, or when external Li was replaced by choline. These data provide evidence for a Ca−Ca exchange mechanism which is activated by certain alkali metal ions. The observations are consistent with a mobile carrier mechanism which can exchange Ca2+ ions from the axoplasm for either 3 Na+ ions, or one Ca2+ and an alkali metal ion (but not Cs) from the external medium. This mechanism may utilize energy from the Na electrochemical gradient to help extrude Ca against an electrochemical gradient.


Cyanide Choline Mobile Carrier External Medium Electrochemical Gradient 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. Baker, P.F. 1970. Sodium-calcium exchange across the nerve cell membrane.In: Calcium and Cellular Function. A.W. Cuthbert, editor. p. 96. Macmillan and Co., Ltd., LondonGoogle Scholar
  2. Baker, P.F. 1972. Transport and metabolism of calcium ions in nerve.Prog. Biophys. Mol. Biol. 24:177PubMedGoogle Scholar
  3. Baker, P.F., Blaustein, M.P. 1968. Sodium-dependent uptake of calcium by crab nerve.Biochim. Biophys. Acta 150:167PubMedGoogle Scholar
  4. Baker, P.F., Blaustein, M.P. 1974. Apparatus for the internal dialysis of giant axons ofLoligo forbesi: A comparison of calcium efflux from intact and dialyzed axons.J. Physiol. 242:52PGoogle Scholar
  5. Baker, P.F., Blaustein, M.P., Hodgkin, A.L., Steinhardt, R.A. 1969a. The influence of calcium on sodium efflux in squid axons.J. Physiol. 200:431PubMedGoogle Scholar
  6. Baker, P.F., Blaustein, M.P., Keynes, R.D., Manil, J., Shaw, T.I., Steinhardt, R.A. 1969b. The ouabain-sensitive fluxes of sodium and potassium in squid giant axons.J. Physiol. 200:459PubMedGoogle Scholar
  7. Baker, P.F., Glitsch, H.G. 1973. Does metabolic energy participate directly in the Na+-dependent extrusion of Ca2+ from squid giant axons?J. Physiol. 233:44PGoogle Scholar
  8. Baker, P.F., Hodgkin, A.L., Ridgeway, E.B. 1971. Depolarization and calcium entry in squid giant axons.J. Physiol. 218:709PubMedGoogle Scholar
  9. Blaustein, M.P. 1974. The interrelationship between sodium and calcium fluxes across cell membranes.Rev. Physiol. Biochem. Pharmacol. 70:33PubMedGoogle Scholar
  10. Blaustein, M.P., Hodgkin, A.L. 1969. The effect of cyanide on the efflux of calcium from squid axons.J. Physiol. 200:497PubMedGoogle Scholar
  11. Blaustein, M.P., Russell, J.M. 1975. Sodium-calcium exchange and calcium-calcium exchange in internally-dialyzed squid axons.Biophys. J. 15 (No. 2, Part 2):313aGoogle Scholar
  12. Blaustein, M.P., Russell, J.M., De Weer, P. 1974. Calcium efflux from internally-dialyzed squid axons: The influence of external and internal cations.J. Supramolec. Struct. 2:558Google Scholar
  13. Brinley, F.J., Jr., Mullins, L.J. 1967. Sodium extrusion by internally-dialyzed squid axons.J. Gen. Physiol. 50:2303PubMedGoogle Scholar
  14. Brinley, F.J., Jr., Mullins, L.J. 1968. Sodium fluxes in internally dialyzed squid axons.J. Gen. Physiol. 52:181PubMedGoogle Scholar
  15. Brinley, F.J., Jr., Mullins, L.J. 1974. Effects of membrane potential on sodium and potassium fluxes in squid axons.Ann. N.Y. Acad. Sci. 242:406PubMedGoogle Scholar
  16. De Weer, P. 1974. Aspects of the recovery processes in nerve.In: MTP International Review of Science, Physiology Series. C.C. Hunt, editor. Vol. 3, Chap. 6. Medical & Technical Publishing Co., Ltd., Div. of Butterworth & Co., Ltd., LondonGoogle Scholar
  17. Di Polo, R. 1973. Calcium efflux from internally dialyzed squid giant axons.J. Gen. Physiol. 62:575PubMedGoogle Scholar
  18. Di Polo, R. 1974. Effect of ATP on the calcium efflux in dialyzed squid giant axons.J. Gen. Physiol. 54:503Google Scholar
  19. Haberer, K. 1965. Measurement of beta activities in aqueous samples utilizing Cerenkov radiation.Atomwirtschaft 10:36. [Translated by A. Kreymeyer,Packard Technical Bulletin 16:1, 1966. Packard Instrument Co., Downers Grove, Illinois]Google Scholar
  20. Luxoro, M., Yañez, E. 1968. Permeability of the giant axon ofDosidicus gigas to calcium ions.J. Gen. Physiol. 51:115SGoogle Scholar
  21. Mullins, L.J., Brinley, F.J., Jr. 1967. Some factors influencing sodium extrusion by internally dialyzed squid axons.J. Gen. Physiol. 50:2333PubMedGoogle Scholar
  22. Nadarajah, A., Leese, B., Joplin, G.F. 1969. Triton X-100 scintillant for counting calcium-45 in biological fluids.Int. J. Appl. Rad. Isotopes 20:733Google Scholar
  23. Portzehl, H., Caldwell, P.C., Rüegg, J.C. 1964. The dependence of contraction and relaxation of muscle fibres from the crabMaia squinado on the internal concentration of free calcium ions.Biochim. Biophys. Acta 79:581PubMedGoogle Scholar
  24. Ussing, H.H. 1947. Interpretation of the exchange of radio-sodium in isolated muscle.Nature 160:262Google Scholar
  25. Wilbrandt, W., Rosenberg, T. 1961. The concept of carrier transport and its corollaries in pharmacology.Pharmacol. Rev. 13:109PubMedGoogle Scholar

Copyright information

© Springer-Verlag New York Inc. 1975

Authors and Affiliations

  • M. P. Blaustein
    • 1
    • 2
  • J. M. Russell
    • 1
    • 2
  1. 1.Department of Physiology and BiophysicsWashington University School of MedicineSt. Louis
  2. 2.Department of Physiology and BiophysicsUniversity of Texas Medical BranchGalveston

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