The Journal of General Physiology
CrossRef
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text (PDF, 1195K)
Right arrow Alert me when this article is cited
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JGP
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Spring, K. R.
Right arrow Articles by Paganelli, C. V.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Spring, K. R.
Right arrow Articles by Paganelli, C. V.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
The Journal of General Physiology, Vol 60, 181-201, Copyright © 1972 by The Rockefeller University Press

ARTICLE

Sodium Flux in Necturus Proximal Tubule under Voltage Clamp

Kenneth R. Spring 1 and Charles V. Paganelli 1

1 From the Department of Physiology, School of Medicine, State University of New York at Buffalo, Buffalo, New York 14214.

Dr. Spring's present address is the Department, of Physiology, Yale University School of Medicine, New Haven, Connecticut 06510.

Na transport and electrical properties of Necturus renal proximal tubules were analyzed, in vivo, by a voltage clamp method which utilizes an axial electrode in the tubule lumen for passage of current and simultaneous determination of net fluid (or Na) flux by the split droplet method. When the average spontaneous transepithelial potential difference of –8 mv (lumen negative) was reduced to zero by current passage, net Na flux doubled from a mean of 107 to 227 pmoles/cm2 per sec. The relationship between flux and potential over the range –25 to +10 mv was nonlinear, with flux equilibrium at –15 mv and droplet expansion at more negative values. Calculated Na permeability at flux equilibrium was 7.0 x 10–6 cm/sec. Voltage transients, similar to those caused by intraepithelial unstirred layers, were observed at the end of clamping periods. Tubular electrical resistance measured by brief square or triangle wave pulses (<100 msec) averaged 43 ohm cm2. The epithelial current-voltage relationship was linear over the range –100 to +100 mv, but displayed marked hysteresis during low frequency (<0.04 Hz) triangle wave clamps. The low transepithelial resistance and large opposing unidirectional ion fluxes suggest that passive ionic movements occur across extracellular shunt pathways, while the voltage transients and current-voltage hysteresis are consistent with the development of a local osmotic gradient within epithelium.

Submitted on November 9, 1971


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 Am. J. Pathol.Home page
M. M. Cloutier, L. Guernsey, C. A. Wu, and R. S. Thrall
Electrophysiological Properties of the Airway: Epithelium in the Murine, Ovalbumin Model of Allergic Airway Disease
Am. J. Pathol., May 1, 2004; 164(5): 1849 - 1856.
[Abstract] [Full Text] [PDF]


  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents