The Localization of Ion-Selective Pumps and Paths in the Plasma Membranes of Turtle Bladders

  • William A. Brodsky
  • Gerhard Ehrenspeck
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 84)


Turtle bladders actively transport Na, Cl, and HCO3 to the serosal fluid; and each ionic flux is independent of the others under short-circuiting conditions. This behavior mimics that of a parallel network of ion-selective, electrically-conductive paths and pumps in each membrane, — a picture consistent with recent evidence along three independent lines. (1) The potential response to increases in mucosal Na concentration indicates that the Na conductance of the apical membrane is 70% of the transepithelial conductance and that the Na transfer across this membrane occurs via an electrically-charged carrier operation. (2) The sidedness and selectivity of transport changes induced by certain agents are the following. Acting from the mucosal side only, amiloride blocks passive Na transfer; and catecholamines (or imidazoles or theophylline) accelerate active anion transport. Acting from the serosal side only, ouabain blocks active Na transport; and disulfonic stilbenes or acetazolamide block passive anion transfers. (3) The surface charge density of the apical membrane differs from that of basal-lateral during free-flow electrophoresis (FFE) of a mixed membrane fraction of epithelial cells. Basal-lateral membrane fragments (containing ouabain-sensitive ATPase and a stilbene-binding protein) migrate toward the positive electrode while apical membrane fragments (contain nor-epinephrine-sensitive adenylate cyclase and cAMP-activated protein kinase) migrate toward the negative electrode. (4) Thus, ouabain, nor-epinephrine, and a disulfonic stilbene are shown to be useful membrane probes for the Na pump, the anion pumps, and the passive anion transfer paths, respectively.


Adenylate Cyclase Apical Membrane Anion Transport Membrane Fragment Bathing Fluid 
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.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Brodsky, W.A. and T.P. Schilb Osmotic properties of the isolated turtle bladder Am. J. Physiol., 208:46–57, 1965PubMedGoogle Scholar
  2. Brodsky, W.A. and T.P. Schilb Ionic mechanisms for sodium and chloride transport across turtle bladders Am. J. Physiol., 210: 997–1008, 1966PubMedGoogle Scholar
  3. Brodsky, W.A., Schilb, T.P. and J.L. Parkes Moderators of anion transport in the isolated turtle bladder Symposium on Acidification; International Congress of Physiology (In Press), 1976Google Scholar
  4. Dowd, F. and A. Schwartz The presence of cyclic AMP-stimulated protein kinase substrates and evidence for endogenous protein kinase activity in various Na, K-ATPase preparations from brain, heart and kidney J. Molec. & Cell, Cardiol., 7:483–497, 1975CrossRefGoogle Scholar
  5. Ehrenspeck, G. and W.A. Brodsky Effects of 4-acetamido-4′-isothiocyano-2,2′-disulfonic stilbene on ion transport in turtle bladders Biochim. Biophys. Acta, 419: 555–558, 1976PubMedCrossRefGoogle Scholar
  6. Gonzalez, C.F. Inhibitory effect of acetazolamide on the active chloride and bicarbonate transport mechanisms across short-circuited turtle bladders Biochim. Biophys. Acta, 193:146–158, 1969PubMedCrossRefGoogle Scholar
  7. Gonzalez, C.F., and T.P. Schilb Acetazolamide sensitive short-circuiting current versus mucosal bicarbonate concentration in turtle bladder Biochim. Biophys. Acta. 193:419–429, 1969PubMedCrossRefGoogle Scholar
  8. Gonzalez, C.F., Shamoo, Y.E. and W.A. Brodsky Electrical nature of active chloride transport across short-circuited turtle bladders Am. J. Physiol., 212:641–650, 1967aGoogle Scholar
  9. Gonzalez, C.F., Shamoo, Y.E., Wyssbrod, H.R., Solinger, R.E., and W.A. Brodsky Electrical nature of sodium transport across the isolated turtle bladder Am. J. Physiol., 213:333–340, 1967bPubMedGoogle Scholar
  10. Hannig, K. The application of free-flow electrophoresis to the separation of macromolecules and particles of biological importance. Handbuch: Modern Separation Methods of Macromolecules and Particles, Ed., Th. Gerritsen, John Wiley & Sons, Inc., Vol. 2, S. 45, 1969Google Scholar
  11. Hannig, K. Electrophoretic separation of Cells and particles by continuous free-flow electrophoresis Handbuch: Techniques of Biochemical and Biophysical Morphology, Ed., D. Glick and R. Rosenbaum, John Wiley & Sons, Inc. N.Y., 1972Google Scholar
  12. Heidrich, H.G., Kinne, R., Kinne-Saffran, E. and R. Hannig The polarity of the proximal tubule cell in rat kidney J. Cell Biol., 54:232–245, 1972PubMedCrossRefGoogle Scholar
  13. Heinz, E. and P. Geck The electrical potential difference as a driving force in Na-linked cotransport of organic solutes. Symposium: “Coupled Transport Phenomena in Cells and Tissues”, Raven Press, Inc., N.Y., N.Y. (In Press), 1976Google Scholar
  14. Hirschhorn, N., and H.S. Frazier Intracellular electrical potential of the epithelium of turtle bladder Am. J. Physiol., 220:1158–1161, 1971PubMedGoogle Scholar
  15. Rothstein, A. Cabantchik, Z. I., Balshin, M. and Juliano, R. Enhancement of anion permeability in lecithin vesicles by hydrophobic proteins extracted from red blood cell membranes. Biochim. Biophys. Res. Commum. 64:144–150, 1975CrossRefGoogle Scholar
  16. Schilb, T.P. and W.A. Brodsky Transient acceleration of transmural water flow by inhibition of sodium transport in turtle bladders Am. J. Physiol., 219:590–596, 1970PubMedGoogle Scholar
  17. Schwartz, I.L., Shlatz, L.J., Kinne-Saffran, E., and R. Kinne Target cell polarity and membrane phosphorylation in relation to the mechanism of action of antidiuretic hormone Proc. Nat. Acad. Sci., 71:2595–2599, 1974PubMedCrossRefGoogle Scholar
  18. Shamoo, Y.E., and W.A. Brodsky The (Na + K)-dependent adenosine triphosphatase in the isolated mucosal cells of turtle bladder. Biochim. Biophys. Acta., 203:111–123, 1970PubMedCrossRefGoogle Scholar
  19. Skou, J.C. The influence of some cations on an adenosine triphosphatase from peripheral nerve Biochim. Biophys. Acta, 23:394–401, 1957PubMedCrossRefGoogle Scholar
  20. Solinger, R.E., Gonzalez, C.F., Shamoo, Y.E., Wyssbrod, H.R. and W.A. Brodsky Effect of ouabain on ion transport mechanisms in the isolated turtle bladder Am. J. Physiol., 215:249–261, 1968PubMedGoogle Scholar
  21. Steinmetz, P.R. Cellular mechanisms of urinary acidification Physiol, Rev., 54:890–956, 1975Google Scholar
  22. Wilczewski, T. and W.A. Brodsky Effect of ouabain and amiloride on Na pathways in turtle bladders Am. J. Physiol., 228:781–790, 1975PubMedGoogle Scholar

Copyright information

© Plenum Press, New York 1977

Authors and Affiliations

  • William A. Brodsky
    • 1
  • Gerhard Ehrenspeck
    • 1
  1. 1.Dept. Physiol. & Biophys., Mount Sinai School of MedicineCUNYN.Y.USA

Personalised recommendations