Summary
By the use of microelectrode techniques, the potential profile and the electrical resistances of the cellular and shunt pathways across the toad urinary bladder epithelium were measured under control conditions and after exposing the mucosal side to solutions of low and high NaCl concentrations and osmolatities. The resistance of the shunt pathway increases at low NaCl concentration (even if the osmolality is kept constant), and decreases at high NaCl concentration (by a nonspecific osmotic mechanism). The inverse relationship between mucosal NaCl concentration and shunt resistance suggests a regulatory mechanism of net sodium transport by reduction of the passive blood-to-urine sodium flux at low urinary sodium concentrations. In addition, the transepithelial potential and the potentials at both cell borders fall in both low and high mucosal NaCl, and the magnitude of these changes is such that they cannot be explained by changes in the shunt pathway alone.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bindslev, N., Tormey, J. M., Pietras, R. J., Wright, E. M. 1974. Electrically and osmotically induced changes in permeability and structure of toad urinary bladder.Biochim. Biophys. Acta 332: 286
Boulpaep, E. L. 1972. Permeability changes of the proximal tubule ofNecturus during saline loading.Amer. J. Physiol. 222: 517
Cereijido, M., Curran, P. F. 1965. Intracellular electrical potentials in frog skin.J. Gen. Physiol. 48:543
DeBermudez, L., Windhager, E. E. 1974. Osmotically induced changes in electrical resistance across distal tubules of rat kidney in vivo.Fed. Proc. 33:387 (Abs.)
DiBona, D. R., Civan, M. M. 1973. Pathways for movement of ions and water across toad urinary bladder. I. Anatomic site of transepithelial shunt pathways.J. Membrane Biol. 12:101
Eisenberg, R. S., Johnson, E. A. 1970. Three-dimensional electrical field problems in physiology.Prog. Biophys. Mol. Biol. 20:1
Erlij, D., Martinez-Palomo, A. 1973. Opening of tight junctions in toad urinary bladders by hypertonic solutions.Fed. Proc. 32:218 (Abs.)
Finn, A. L. 1971. The kinetics of sodium transport in the toad bladder. II. Dual effects of vasopressin.J. Gen. Physiol. 57:349
Finn, A. L. 1974. Transepithelial potential difference in toad urinary bladder is not due to ionic diffusion.Nature 250:495
Frömter, E. 1972. The route of passive ion movement through the epithelium ofNecturus gallbladder.J. Membrane Biol. 8:259
Gatzy, J. T., Clarkson, T. W. 1965. The effect of mucosal and serosal solution cations on bioelectric properties of the isolated toad bladder.J. Gen. Physiol. 48:647
Goodenough, D. A., Revel, J. P. 1970. A fine structural analysis of intercellular junctions in the mouse liver.J. Cell. Biol. 45:272
Leb, D. E., Hoshiko, T., Lindley, B. D. 1965. Effects of alkali metal cations on the potential across toad and bullfrog urinary bladder.J. Gen. Physiol. 48:527
Lifschitz, M. D., Garcia, J. A., Earley, L. E. 1973. Effect of passive water absorption on transepithelial movement of extracellular solutes in rat intestine.Kidney Int. 4:362
Lindemann, B., Gebhardt, U. 1973. Delayed changes of Na-permeability in response to steps of (Na) at the outer surface of frog skin and frog bladder.In: Transport Mechanisms in Epithelia. H. H. Ussing and N. A. Thorn, editors. p. 115. Munksgaard, Copenhagen
Reuss, L., Finn, A. L. 1974. Passive electrical properties of toad urinary bladder epithelium: Intercellular electrical coupling and transepithelial cellular and shunt conductances.J. Gen. Physiol. 64:1
Reuss, L., Finn, A. L. 1975. Dependence of serosal membrane potential on mucosal membrane potential in toad urinary bladder.Biophys. J. 15:71
Shultz, S. G. 1972. Electrical potential differences and electromotive forces in epithelial tissues.J. Gen. Physiol. 59:794
Shiba, H. 1971. Heavisides “Bessel Cable” as an electric model for flat simple epithelial cells with low resistive junctional membranes.J. Theoret. Biol. 30:59
Tasaki, I., Polley, E. H., Orrego, F. 1954. Action potentials from individual elements in cat geniculate and striate cortex.J. Neurophysiol. 17:454
Urakabe, S., Handler, J. D., Orloff, J. 1970. Effect of hypertonicity on permeability properties of the toad bladder.Amer. J. Physiol. 218:1179
Ussing, H. H., Windhager, E. E. 1964. Nature of shunt path and active sodium transport path through frog skin epithelium.Acta Physiol. Scand. 61:484
Wade, J. B., DiScala, V. A. 1971. The effect of osmotic flow on the distribution of horseradish peroxidase within the intercellular space of toad bladder epithelium.J. Cell. Biol. 51:553
Wade, J. B., Revel, J. P., DiScala, V. A. 1973. Effect of osmotic gradients on intercellular junctions of the toad bladder.Amer. J. Physiol. 224:407
Wiederholt, M., Giebisch, G. 1974. Some electrophysiological properties of the distal tubule of theAmphiuma kidney.Fed. Proc. 33:387 (Abs.)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Reuss, L., Finn, A.L. Effects of changes in the composition of the mucosal solution on the electrical properties of the toad urinary bladder epithelium. J. Membrain Biol. 20, 191–204 (1975). https://doi.org/10.1007/BF01870636
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01870636