The Journal of Membrane Biology

, Volume 57, Issue 1, pp 59–71 | Cite as

Current-voltage analysis of apical sodium transport in toad urinary bladder: Effects of inhibitors of transport and metabolism

  • Lawrence G. Palmer
  • Isidore S. Edelman
  • Bernd Lindemann


The basal-lateral surface of the epithelium of the urinary bladder of the toad (Bufo marinus) was depolarized by exposure of the serosal surface to 85mm KCL and 50mm sucrose. The extent of depolarization appeared to be virtually complete, as evaluated by the invariance in the transepithelial electrical potential difference and conductance on addition of nystatin (a monovalent cation ionophore) to the serosal medium. The Na-specific current (INa) was defined as the current sensitive to the removal of Na from the mucosal medium or inhibitable by addition of amiloride to this medium. In the presence of the high K-sucrose serosal medium, rapid, serial, stepwise clamping of the transepithelial voltage (V) yielded a curvilinear dependence ofINa onV; which is taken to represent theI–V curve of the apical Na channels. The constant field equation (Goldman, D.E. 1943;J. Gen. Physiol.27:37) fits theI–V data points closely, allowing estimates to be made of the permeability to Na of the apical membrane (PNa) and of the intracellular Na activity (Na c ). Exposure of the apical surface to amiloride (5×10−7m) decreasedPNa in proportion to the decrease inINa (i.e., ∼70%) but decreased Na c only 25%. In contrast, an equivalent lent reduction inINa elicited by exposure of the basallateral surface to ouabain was accompanied by only a 20% decrease inPNa and a sixfold increase in Na c . The effects of amiloride onPNa and ouabain on Na c are consistent with the primary pharmacological actions of these drugs. In addition,PNa appears to be under metabolic control, in that 2-deoxyglucose, a specific inhibitor of glycolysis, decreasedINa andPNa proportionately, and lowered Na c marginally, effects indistinguishable from those obtained with amiloride.


Ouabain Amiloride Nystatin Electrical Potential Difference Toad Urinary Bladder 
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  1. Bentley, P.J. 1968. Amiloride: A potent inhibitor of sodium transport across the toad bladder.J. Physiol. (London) 195:317Google Scholar
  2. Biber, T.U.L. 1971. Effect of changes in transepithelial transport on the uptake of sodium across the outer surface of the frog skin.J. Gen Physiol. 58:131PubMedGoogle Scholar
  3. Blaustein, M.P. 1977. Effects of internal and external cations and ATP on sodium-calcium and calcium-calcium exchange in squid axons.Biophys. J. 20:79PubMedGoogle Scholar
  4. Bonting, S.L., Canaday, M.R. 1964. Na−K activated adenosine triphosphatase and sodium transport in toad bladder.Am J. Physiol. 207:1005PubMedGoogle Scholar
  5. Cass, A., Finkelstein, A., Krespi, V. 1970. The ion permeability induced in thin lipid membranes by the polyene antibiotics nystatin and amphotericin B.J. Gen. Physiol. 56:100CrossRefPubMedGoogle Scholar
  6. Civan, M.M. 1970. Effects of active sodium tansport on currentvoltage relationship of toad bladder.Am. J. Physiol. 219:234PubMedGoogle Scholar
  7. Civan, M.M., Frazier, H.S. 1968. The site of the stimulatory action of vasopressin on sodium transport in the toad bladder.J. Gen. Physiol. 51:589PubMedGoogle Scholar
  8. DeLong, J., Civan, M.M. 1978. Dissociation of cellular K+ accumulation from net Na+ transport by toad urinary bladder.J. Membrane Biol. 42:19Google Scholar
  9. DeLong, J., Civan, M.M. 1979. Intracellular potassium activity associated with potassium depletion in toad urinary bladder.In: Hormonal Control of Epithelial Transport. J. Bourget, J. Chevalier, M. Parisi, and P. Ripoche, editors. INSERM, ParisGoogle Scholar
  10. DeLorenzo, R.J., Walton, K.G., Curran, P.F., Greengard, P. 1973. Regulation of phosphorylation of a specific protein in toad bladder membrane by antidiuretic hormone and cyclic AMP, and its possible relationship to membrane permeability changes.Proc. Nat. Acad. Sci. USA 70:880PubMedGoogle Scholar
  11. De Weer, P. 1973. Na+, K+ exchange and Na+, Na+ exchange in the giant axon of the squid.Ann. N. Y. Acad. Sci. 242:434Google Scholar
  12. Dörge, A., Nagel, W. 1970. Effect of amiloride on sodium transport in frog skin. II. Sodium transport pool and unidirectional fluxes.Google Scholar
  13. Ehrlich, E.N., Crabbé, J. 1968. The mechanism of action of amipramizide.Pfluegers Arch. 302:79Google Scholar
  14. Erlij, D., Smith, M.W. 1973. Sodium uptake by frog skin and its modification by inhibitors of transepithelial Na transport.J. Physiol. (London) 228:221Google Scholar
  15. Essig, A., Leaf, A. 1963. The role of potassium in active transport of sodium by the toad bladder.J. Gen. Physiol. 46:505Google Scholar
  16. Finn, A.L. 1975. Action of ouabain on sodium transport in toad urinary bladder: Evidence for two pathways for sodium entry.J. Gen. Physiol. 65:503PubMedGoogle Scholar
  17. Frazier, H.S. 1962. The electrical potential profile of the isolated toad bladder.J. Gen. Physiol. 45:515PubMedGoogle Scholar
  18. Frazier, H.S., Leaf, A. 1963. The electrical characteristics of active sodium transport in the toad bladder.J. Gen. Physiol. 46:491Google Scholar
  19. Fuchs, W., Hviid Larsen, E., Lindemann, B. 1977. Current-voltage curve of sodium channels and concentration dependence of sodium permeability in frog skin.J. Physiol. (London) 267:137Google Scholar
  20. Goldman, D.E. 1943. Potential, impedance and rectification in membranes.J. Gen. Physiol. 27:37Google Scholar
  21. Grinstein, S., Erlij, D. 1978. Intracellular Ca++ and the regulation of Na+ transport in the frog skin.Proc. R. Soc. London B 202:353Google Scholar
  22. Helman, S.I., Fisher, R.S. 1977. Microelectrode studies of the active Na transport pathway of frog skin.J. Gen. Physiol. 69:571PubMedGoogle Scholar
  23. Helman, S.I. Nagel, W., Fisher, R.S. 1979. Ouabain on active transepithelial sodium transport in frog skin.J. Gen. Physiol. 74:105Google Scholar
  24. Herrera, F.C. 1966. Action of ouabain on sodium transport in the toad urinary bladder.Am J. Physiol. 210:980PubMedGoogle Scholar
  25. Higgins, J.T., Jr., Gebler, B., Frömter, E. 1977. Electrical properties of amphibian urinary bladder epithelia. II. The cell potential profile inNecturus maculosus.Pfluegers Arch. 371:87Google Scholar
  26. Hong, C.D., Essig, A. 1976. Effects of 2-deoxy-d-glucose, amiloride, vasopressin and ouabain on active conductance andE Na in the toad bladder.J. Membrane Biol. 28:121Google Scholar
  27. Koefoed-Johnsen, V., Ussing, H.H. 1958. The nature of the frog skin potential.Acta Physiol. Scand. 42:298PubMedGoogle Scholar
  28. Larsen, E.H. 1973. Effect of amiloride, cyanide and ouabain on the active transport pathway in toad skin.In: Transport Mechanisms in Epithelia. H.H. Ussing and N.A. Thorn, editors. pp. 131–143. Munsgaard, Copenhagen and Academic Press. New YorkGoogle Scholar
  29. Lehninger, A.L. 1971.In: Bioenergetics, W.A. Benjamin, Menlo Park, CAGoogle Scholar
  30. Lewis, S.A., Eaton, D.C., Diamond, J.M. 1976. The mechanism of Na+ transport by rabbit urinary bladder.J. Membrane Biol. 28:41Google Scholar
  31. Lewis, S.A., Wills, N.K., Eaton, D.C. 1978. Basolateral membrane potential of a tight epithelium: Ionic diffusion and electrogenic pumps.J. Membrane Biol. 41:117Google Scholar
  32. Lien, E.L., Goodman, D.B.P., Rasmussen, H. 1975. Effects of an acetyl-coenzyme A carboxylase inhibitor and a sodium-sparing diuretic on aldosterone-stimulated sodium transport, lipid synthesis, and phospholipid fatty acid composition in the toad urinary bladder.Biochemistry 14:2749PubMedGoogle Scholar
  33. Lindemann, B. 1975. Impalement artifacts in microelectrode recordings of epithelial membrane potentials.Biophys. J. 15:1161PubMedGoogle Scholar
  34. Lindemann, B. 1977. Circuit analysis of epithelial ion transport. II: Concentration and voltage-dependent conductances and sample calculations.Bioelectrochem. Bioenerg. 4:287Google Scholar
  35. Lindemann, B., Van Driessche, W. 1978. The mechanism of Na uptake through Na-selective channels in the epithelium of frog skin. Membrane Transport Processes. Vol. 1. J.F. Hoffman, editor. Raven Press, New YorkGoogle Scholar
  36. Lipton, P., Edelman, I.S. 1971. Effects of aldosterone and vasopressin on electrolytes of toad bladder epithelial cells.Am. J. Physiol. 221:733PubMedGoogle Scholar
  37. Liu, A.Y.C., Greengard, P. 1974. Aldosterone-induced increase in protein phosphatase activity of toad bladder.Proc. Nat. Acad. Sci. USA 71:3869PubMedGoogle Scholar
  38. Macknight, A.D.C. 1977. Contribution of mucosal chloride to chloride in toad bladder epithelial cells.J. Membrane Biol. 36:55Google Scholar
  39. Macknight, A.D.C., Civan, M.M., Leaf, A. 1975. The sodium transport pool in toad urinary bladder epithelia cells.J. Membrane Biol. 20:365Google Scholar
  40. Macknight, A.D.C., DiBona, D.R., Leaf, A., Civan, M.M. 1971. Measurement of the composition of epithelial cells from the toad urinary bladder.J. Membrane Biol. 6:108Google Scholar
  41. MacRobbie, E.A.C., Ussing, H.H. 1966. Osmotic behaviour of the epithelial cells of frog skin.Acta Physiol. Scand. 53:348Google Scholar
  42. Marty, A., Finkelstein, A. 1975. Pores formed on lipid bilayer membranes by nystatin.J. Gen. Physiol. 65:515CrossRefPubMedGoogle Scholar
  43. Masur, S.A., Holtzman, E., Walter, R. 1972. Hormone stimulated exocytosis in the toad urinary bladder.J. Cell Biol. 52:211PubMedGoogle Scholar
  44. Nagel, W., Dörge, A. 1970. Effects of amiloride on sodium transport of frog skin. I. Action on intracellular sodium content.Pfluegers Arch. 317:84Google Scholar
  45. Nelson, D.J., Ehrenfeld, J., Lindemann, B. 1978. Volume changes and potential artifacts of epithelial cells of frog skin following impalement with microelectrodes filled with 3m KCl.J. Membrane Biol. 40:91Google Scholar
  46. Reuss, L., Finn, A.L. 1974. Passive electrical properties of toad urinary bladder epithelium: Intracellular electrical coupling and transepithelial cellular and shunt conductances.J. Gen. Physiol. 64:1PubMedGoogle Scholar
  47. Reuss, L., Finn, A.L. 1975. Dependence of serosal membrane potential on mucosal membrane potential in toad urinary bladder.Biophys. J. 15:71PubMedGoogle Scholar
  48. Rick, R., Dörge, A., Macknight, A.D.C., Leaf, A., Thuran, K. 1978. Electron microprobe analysis of the different epithelial cells of toad urinary bladder.J. Membrane Biol. 39:257Google Scholar
  49. Rossier, B.C., Wilce, P.A., Edelman, I.S. 1974. Kinetics of RNA labeling in toad bladder epithelium: Effects of aldosterone and other steroids.Proc. Nat. Acad. Sci. USA 71:3101PubMedGoogle Scholar
  50. Russell, J.M., Eaton, D.C., Brodwick, M.S. 1977. Effects of nystatin on membrane conductance and internal ion activities inAplysia neurons.J. Membrane Biol. 37:137Google Scholar
  51. Saito, T., Lief, P.D., Essig, A. 1974. Conductance of active and passive pathways in the toad bladder.Am. J. Physiol. 226:1265PubMedGoogle Scholar
  52. Scott, W.N., Reich, I.M., Goodman, D.B.P. 1979. Inhibition of fatty acid synthesis prevents incorporation of aldosterone-induced proteins into membranes.J. Biol. Chem. 254:4957PubMedGoogle Scholar
  53. Spooner, P.M., Edelman, I.S. 1975. Further studies on the effect of aldosterone on electrical resistance of toad bladder.Biochim. Biophys. Acta 406:304PubMedGoogle Scholar
  54. Taylor, A., Windhager, E.E. 1979. Possible role of cytosalic calcium and Na−Ca exchange in regulation of transepithelial sodium transport.Am. J. Physiol. 236:F505PubMedGoogle Scholar
  55. Turnheim, K., Frizzell, R.A., Schultz, S.G. 1978. Interaction between cell Na and the amiloride-sensitive sodium entry step in rabbit colon.J. Membrane Biol. 39:233Google Scholar
  56. Webb, J.L. 1966.In: Enzymes and Metabolic Inhibitors. Vol. II, p. 386. Academic Press, New YorkGoogle Scholar

Copyright information

© Springer-Verlag New York Inc. 1980

Authors and Affiliations

  • Lawrence G. Palmer
    • 1
    • 2
  • Isidore S. Edelman
    • 1
    • 2
  • Bernd Lindemann
    • 1
    • 2
  1. 1.II. Physiologisches Institut der Universität des SaarlandesHomburgWest Germany
  2. 2.Departments of Medicine and of Biochemistry and BiophysicsUniversity of California School of MedicineSan Francisco

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