Pseudo-streaming potentials in Necturus gallbladder epithelium. I. Paracellular origin of the transepithelial voltage changes.

Reuss, Luis; Simon, Bruce J.; Xi, Zhijian

doi:10.1085/jgp.99.3.297

Cited by 11 publications

(7 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Pseudo-streaming potentials are generated by solute polarization in unstirred layers adjacent to the cell membranes or within the LIS (37). Although they have been interpreted as indicators of changes in LIS composition, this is model-dependent and thus must be done with caution (44,45). In sum, these electrophysiologic methods do not yield direct information about the magnitude of water flows across the tight junctions of fluid transporting epithelia.…”

Section: Electrophysiologic Methodsmentioning

confidence: 99%

Routes and Mechanism of Fluid Transport by Epithelia

Spring

1998

Annu. Rev. Physiol.

163

115

View full text Add to dashboard Cite

The mechanism of fluid transport by leaky epithelia and the route taken by the transported fluid are in dispute. A consideration of current mathematical models for coupling of solutes and water, as well as the methodologies for the study of fluid transport, shows that local osmosis best accounts for water movement. Although it seems virtually certain that the tight junctions are water permeable, the fraction of absorbed fluid that crosses the tight junction cannot yet be determined with confidence.

show abstract

Section: Electrophysiologic Methodsmentioning

confidence: 99%

Routes and Mechanism of Fluid Transport by Epithelia

Spring

1998

Annu. Rev. Physiol.

163

115

View full text Add to dashboard Cite

show abstract

“…In the preceding paper we compared the time courses of the transepithelial voltage changes produced by an apical isoosmotic partial substitution of NaCl with TBACI (bi-ionic potential), or by addition of sucrose to the NaC1-Ringer's apical bathing solution (apparent streaming potential). The half-times for the on and off voltage changes were longer for the apparent streaming potential, by 2.5-to 4-fold, and by 5to 6-fold, respectively (Table V of Reuss et al, 1992). This result appears to be inconsistent with a true streaming potential, since in such a case the ion flow in response to the osmotic challenge should be linear with the difference in osmolality, and hence the streaming potential should develop pari-passu with the change in [sucrose] at the cell surface.…”

Section: Resultsmentioning

confidence: 99%

“…The techniques used to isolate and mount the gallbladder were in general as described in previous publications (Altenberg, Copello, Cotton, Dawson, Segal, Wehner, and Reuss, 1990) and in the preceding paper (Reuss et al, 1992).…”

Section: Tissues and Solutionsmentioning

confidence: 99%

“…In the preceding article (Reuss, Simon, and Xi, 1992) we presented experiments which demonstrate that apparent streaming potentials can be elicited in Necturus gallbladder epithelium by changing the concentration of an impermeant nonelectrolyte (sucrose) in the apical bathing solution. The results indicate that the "permeant" species in NaCI-Ringer's solution is Na ÷, in agreement with previous studies of paracellular ion permselectivity of this epithelium (Reuss and Finn, 1975;Van Os and Slegers, 1975).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Pseudo-streaming potentials in Necturus gallbladder epithelium. II. The mechanism is a junctional diffusion potential.

Reuss

Simon

Cotton

1992

The Journal of General Physiology

Self Cite

View full text Add to dashboard Cite

The mechanisms of apparent streaming potentials elicited across Necturus gallbladder epithelium by addition or removal of sucrose from the apical bathing solution were studied by assessing the time courses of: (a) the change in transepithelial voltage (Vm,), (b) the change in osmolality at the cell surface (estimated with a tetrabutylammonium [TBA+]-selective microelectrode, using TBA + as a tracer for sucrose), and (c) the change in cell impermeant solute concentration ([TMA+], measured with an intracellular double-barrel TMA+-selective microelectrode after loading the cells with TMA ÷ by transient permeabilization with nystatin). For both sucrose addition and removal, the time courses of V=, were the same as the time courses of the voltage signals produced by [TMA÷]~, while the time courses of the voltage signals produced by [TBA*]o were much faster. These results suggest that the apparent streaming potentials are caused by changes of [NaCI] in the lateral intercellular spaces, whose time course reflects the changes in cell water volume (and osmolality) elicited by the alterations in apical solution osmolality. Changes in cell osmolality are slow relative to those of the apical solution osmolality, whereas lateral space osmolality follows cell osmolality rapidly, due to the large surface area of lateral membranes and the small volume of the spaces. Analysis of a simple mathematical model of the epithelium yields an apical membrane Lp in good agreement with previous measurements and suggests that elevations of the apical solution osmolality elicit rapid reductions in junctional ionic selectivity, also in good agreement with experimental determinations. Elevations in apical solution [NaCI] cause biphasic transepithelial voltage changes: a rapid negative Vm, change of similar time course to that of a Na+/TBA + bi-ionic potential and a slow positive Vm~ change of similar time course to that of the sucrose-induced apparent streaming potential. We conclude that the Vm, changes elicited by addition of impermeant Address reprint requests to Dr.

show abstract

“…These changes can be explained by paracellular pseudo-streaming potentials caused by water flow from apical to basolateral solution with hyposmotic solution and from basolateral to apical solution with hyperosmotic solution. These voltage changes, because of their small magnitude, do not contribute significantly to the changes in cell membrane voltages ( Reuss et al, 1992 a , b ). There were also significant changes in R t : a decrease with hyp-osmotic solution and an increase with hyperosmotic solution.…”

Section: Resultsmentioning

confidence: 99%

Cell Swelling Activates the K+ Conductance and Inhibits the Cl− Conductance of the Basolateral Membrane of Cells from a Leaky Epithelium

Torres

Subramanyam

Altenberg

et al. 1997

The Journal of General Physiology

View full text Add to dashboard Cite

Necturus gallbladder epithelial cells bathed in 10 mM HCO3/1% CO2 display sizable basolateral membrane conductances for Cl− (GCl b) and K + (GK b). Lowering the osmolality of the apical bathing solution hyperpolarized both apical and basolateral membranes and increased the K +/Cl− selectivity of the basolateral membrane. Hyperosmotic solutions had the opposite effects. Intracellular free-calcium concentration ([Ca2+]i) increased transiently during hyposmotic swelling (peak at ∼30 s, return to baseline within ∼90 s), but chelation of cell Ca2+ did not prevent the membrane hyperpolarization elicited by the hyposmotic solution. Cable analysis experiments showed that the electrical resistance of the basolateral membrane decreased during hyposmotic swelling and increased during hyperosmotic shrinkage, whereas the apical membrane resistance was unchanged in hyposmotic solution and decreased in hyperosmotic solution. We assessed changes in cell volume in the epithelium by measuring changes in the intracellular concentration of an impermeant cation (tetramethylammonium), and in isolated polarized cells measuring changes in intracellular calcein fluorescence, and observed that these epithelial cells do not undergo measurable volume regulation over 10–12 min after osmotic swelling. Depolarization of the basolateral membrane voltage (Vcs) produced a significant increase in the change in Vcs elicited by lowering basolateral solution [Cl−], whereas hyperpolarization of Vcs had the opposite effect. These results suggest that: (a) Hyposmotic swelling increases GK b and decreases G Cl b. These two effects appear to be linked, i.e., the increase in G K b produces membrane hyperpolarization, which in turn reduces G Cl b. ( b) Hyperosmotic shrinkage has the opposite effects on GK b and G Cl b. ( c) Cell swelling causes a transient increase in [Ca2+]i, but this response may not be necessary for the increase in GK b during cell swelling.

show abstract

Pseudo-streaming potentials in Necturus gallbladder epithelium. I. Paracellular origin of the transepithelial voltage changes.

Cited by 11 publications

References 49 publications

Routes and Mechanism of Fluid Transport by Epithelia

Routes and Mechanism of Fluid Transport by Epithelia

Pseudo-streaming potentials in Necturus gallbladder epithelium. II. The mechanism is a junctional diffusion potential.

Cell Swelling Activates the K+ Conductance and Inhibits the Cl− Conductance of the Basolateral Membrane of Cells from a Leaky Epithelium

Contact Info

Product

Resources

About