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. 1968 Jan 1;51(1):47–64. doi: 10.1085/jgp.51.1.47

Nature of the Schwann Cell Electrical Potential

Effects of the external ionic concentrations and a cardiac glycoside

Jorge Villegas 1, Raimundo Villegas 1, Máximo Giménez 1
PMCID: PMC2201155  PMID: 5642473

Abstract

The effects on the Schwann cell electrical potential of external ionic concentrations and of K-strophanthoside were investigated. Increasing (K)o depolarized the cell. The potential is related to the logarithm of (K)o in a quasi-linear fashion. The linear portion of the curve has a slope of 45 mv/ten-fold change in (K)o. Diminutions of (Na)o and (Cl)o produced only small variations in the potential. Calcium and magnesium can be replaced by 44 mM calcium without altering the potential. Increase of (Ca)o to 88 mM produced about 10 mv hyperpolarization. The cell was hyperpolarized by 11 mv and 4 mv within 1 min after applying K-strophanthoside at concentrations of 10-3 and 10-5 M, respectively. No variations of cellular potassium, sodium, or chloride were observed 3 min after applying the glycoside. The hyperpolarization caused by 10-3 M K-strophanthoside was not observed when (K)o was diminished to 1 or 0.1 mM or was increased to 30 mM. At a (K)o of 30 mM, 10-2 M strophanthoside was required to produce the hyperpolarizing effect. In high calcium, the cell was further hyperpolarized by the glycoside. The initial hyperpolarization caused by the glycoside was followed by a gradual depolarization and a decrease of the cellular potassium concentration. The results indicate that the Schwann cell potential of about -40 mv is due to ionic diffusion, mainly of potassium, and to a cardiac glycoside-sensitive ion transport process.

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Selected References

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

  1. ADRIAN R. H. The effect of internal and external potassium concentration on the membrane potential of frog muscle. J Physiol. 1956 Sep 27;133(3):631–658. doi: 10.1113/jphysiol.1956.sp005615. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. FRANKENHAEUSER B., HODGKIN A. L. The action of calcium on the electrical properties of squid axons. J Physiol. 1957 Jul 11;137(2):218–244. doi: 10.1113/jphysiol.1957.sp005808. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. GLYNN I. M. The action of cardiac glycosides on sodium and potassium movements in human red cells. J Physiol. 1957 Apr 3;136(1):148–173. doi: 10.1113/jphysiol.1957.sp005749. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. HUXLEY A. F. Ion movements during nerve activity. Ann N Y Acad Sci. 1959 Aug 28;81:221–246. doi: 10.1111/j.1749-6632.1959.tb49311.x. [DOI] [PubMed] [Google Scholar]
  5. Kuffler S. W., Nicholls J. G., Orkand R. K. Physiological properties of glial cells in the central nervous system of amphibia. J Neurophysiol. 1966 Jul;29(4):768–787. doi: 10.1152/jn.1966.29.4.768. [DOI] [PubMed] [Google Scholar]
  6. MACROBBIE E. A., USSING H. H. Osmotic behaviour of the epithelial cells of frog skin. Acta Physiol Scand. 1961 Nov-Dec;53:348–365. doi: 10.1111/j.1748-1716.1961.tb02293.x. [DOI] [PubMed] [Google Scholar]
  7. NICHOLLS J. G., KUFFLER S. W. EXTRACELLULAR SPACE AS A PATHWAY FOR EXCHANGE BETWEEN BLOOD AND NEURONS IN THE CENTRAL NERVOUS SYSTEM OF THE LEECH: IONIC COMPOSITION OF GLIAL CELLS AND NEURONS. J Neurophysiol. 1964 Jul;27:645–671. doi: 10.1152/jn.1964.27.4.645. [DOI] [PubMed] [Google Scholar]
  8. SANDERSON P. H. Potentiometric determination of chloride in biological fluids. Biochem J. 1952 Nov;52(3):502–505. doi: 10.1042/bj0520502. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. SCHATZMANN H. J. Herzglykoside als Hemmstoffe für den aktiven Kalium- und Natriumtransport durch die Erythrocytenmembran. Helv Physiol Pharmacol Acta. 1953;11(4):346–354. [PubMed] [Google Scholar]
  10. VILLEGAS R., GIMENEZ M., VILLEGAS L. The Schwann-cell electrical potential in the squid nerve. Biochim Biophys Acta. 1962 Aug 27;62:610–612. doi: 10.1016/0006-3002(62)90255-x. [DOI] [PubMed] [Google Scholar]
  11. VILLEGAS R., VILLEGAS G. M. Characterization of the membranes in the giant nerve fiber of the squid. J Gen Physiol. 1960 May;43:73–103. doi: 10.1085/jgp.43.5.73. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. VILLEGAS R., VILLEGAS L., GIMENEZ M., VILLEGAS G. M. Schwann cell and axon electrical potential differences. Squid nerve structure and excitable membrane location. J Gen Physiol. 1963 May;46:1047–1064. doi: 10.1085/jgp.46.5.1047. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Villegas J., Villegas L., Villegas R. Sodium, potassium, and chloride concentrations in the Schwann cell and axon of the squid nerve fiber. J Gen Physiol. 1965 Sep;49(1):1–7. doi: 10.1085/jgp.49.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. WHITTEMBURY G., SUGINO N., SOLOMON A. K. Ionic permeability and electrical potential differences in Necturus kidney cells. J Gen Physiol. 1961 Mar;44:689–712. doi: 10.1085/jgp.44.4.689. [DOI] [PMC free article] [PubMed] [Google Scholar]

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