Direct measurement of the membrane potential of ehrlich ascites tumor cells: Lack of effect of valinomycin and ouabain

Thomas C. Smith, Charles Levinson

Research output: Contribution to journalArticlepeer-review

21 Scopus citations

Abstract

The membrane potential of Ehrlich ascites tumor cells and the effects of valinomycin and ouabain upon it have been determined. The membrane potential in control cells was 12.0 mV, inside negative. Neither valinomycin nor ouabain alone affected this value. However, valinomycin and ouabain in combination resulted in a slight hyperpolarization of the membrane. Concomitant determinations of cellular Na+ K+ and Cl- showed that valinomycin induced net losses of K+ and Cl- and a net gain in Na+ when compared to ouabain-inhibited cells. K+ permeability was increased by approximately 30% in the presence of valinomycin. In addition, valinomycin caused a rapid depletion of cellular ATP. Inhibition of Na/K transport by ouabain was without sparing effect on the rate of ATP depletion. Possible mechanisms for the electroneutral increase in K+ permeability induced by valinomycin are discussed.

Original languageEnglish (US)
Pages (from-to)349-365
Number of pages17
JournalThe Journal of Membrane Biology
Volume23
Issue number1
DOIs
StatePublished - Dec 1975
Externally publishedYes

ASJC Scopus subject areas

  • Biophysics
  • Physiology
  • Cell Biology

Fingerprint

Dive into the research topics of 'Direct measurement of the membrane potential of ehrlich ascites tumor cells: Lack of effect of valinomycin and ouabain'. Together they form a unique fingerprint.

Cite this