Skip to main content
PMC home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1971 Nov;218(3):599–608. doi: 10.1113/jphysiol.1971.sp009635

The independence of electrogenic sodium transport and membrane potential in a molluscan neurone

Michael F Marmor
PMCID: PMC1331603  PMID: 5133950

Abstract

1. The current—voltage relations of the Anisodoris giant neurone (G cell) were studied in the presence and absence of Na pump activity.

2. Inhibition of the electrogenic Na pump with ouabain had no effect on either the presence at warm temperatures (10-15° C), or absence at cold temperatures (0-5° C), of inward-going rectification.

3. Abolition of inward-going rectification in the warm, by replacement of external K with Rb, did not affect the electrogenic Na pump.

4. The current generated by the electrogenic pump was essentially constant between the membrane potentials of — 30 and — 100 mV.

5. The potential produced by the electrogenic pump can be predicted by a modification of the constant field equation.

6. It is estimated that the energy required to extrude Na was between 3160 and 3700 cal/g-atom, and that uncoupled Na efflux during pump activity was typically between 0·2 and 4·0 p-mole/cm2.sec.

Full text

PDF
602

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. ADRIAN R. H. THE RUBIDIUM AND POTASSIUM PERMEABILITY OF FROG MUSCLE MEMBRANE. J Physiol. 1964 Dec;175:134–159. doi: 10.1113/jphysiol.1964.sp007508. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Adrian R. H., Slayman C. L. Membrane potential and conductance during transport of sodium, potassium and rubidium in frog muscle. J Physiol. 1966 Jun;184(4):970–1014. doi: 10.1113/jphysiol.1966.sp007961. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. CONWAY E. J., KERNAN R. P., ZADUNAISKY J. A. The sodium pump in skeletal muscle in relation to energy barriers. J Physiol. 1961 Feb;155:263–279. doi: 10.1113/jphysiol.1961.sp006626. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Fozzard H. A., Kipnis D. M. Regulation of intracellular sodium concentrations in rat diaphragm muscle. Science. 1967 Jun 2;156(3779):1257–1260. doi: 10.1126/science.156.3779.1257. [DOI] [PubMed] [Google Scholar]
  5. GLYNN I. M. THE ACTION OF CARDIAC GLYCOSIDES ON ION MOVEMENTS. Pharmacol Rev. 1964 Dec;16:381–407. [PubMed] [Google Scholar]
  6. Gorman A. L., Marmor M. F. Contributions of the sodium pump and ionic gradients to the membrane potential of a molluscan neurone. J Physiol. 1970 Nov;210(4):897–917. doi: 10.1113/jphysiol.1970.sp009248. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Gorman A. L., Marmor M. F. Temperature dependence of the sodium-potassium permeability ratio of a molluscan neurone. J Physiol. 1970 Nov;210(4):919–931. doi: 10.1113/jphysiol.1970.sp009249. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. HODGKIN A. L., KATZ B. The effect of sodium ions on the electrical activity of giant axon of the squid. J Physiol. 1949 Mar 1;108(1):37–77. doi: 10.1113/jphysiol.1949.sp004310. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. HODGKIN A. L., KEYNES R. D. Active transport of cations in giant axons from Sepia and Loligo. J Physiol. 1955 Apr 28;128(1):28–60. doi: 10.1113/jphysiol.1955.sp005290. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. HOROWICZ P., GERBER C. J. EFFECTS OF EXTERNAL POTASSIUM AND STROPHANTHIDIN ON SODIUM FLUXES IN FROG STRIATED MUSCLE. J Gen Physiol. 1965 Jan;48:489–514. doi: 10.1085/jgp.48.3.489. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. MULLINS L. J., AWAD M. Z. THE CONTROL OF THE MEMBRANE POTENTIAL OF MUSCLE FIBERS BY THE SODIUM PUMP. J Gen Physiol. 1965 May;48:761–775. doi: 10.1085/jgp.48.5.761. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Marmor M. F. Anomalous rectification and electrogenic sodium transport in a molluscan neuron. Nature. 1970 Jun 27;226(5252):1252–1253. doi: 10.1038/2261252a0. [DOI] [PubMed] [Google Scholar]
  13. Marmor M. F. The effects of temperature and ions on the current-voltage relation and electrical characteristics of a molluscan neurone. J Physiol. 1971 Nov;218(3):573–598. doi: 10.1113/jphysiol.1971.sp009634. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Moreton R. B. An investigation of the electrogenic sodium pump in snail neurones, using the constant-field theory. J Exp Biol. 1969 Aug;51(1):181–201. doi: 10.1242/jeb.51.1.181. [DOI] [PubMed] [Google Scholar]
  15. Rapoport S. I. The sodium-potassium exchange pump: relation of metabolism to electrical properties of the cell. I. Theory. Biophys J. 1970 Mar;10(3):246–259. doi: 10.1016/S0006-3495(70)86297-X. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES