The Journal of General Physiology
World Precision Insruments
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow PDF (Full Text)
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 Russell, J. M.
Right arrow Articles by Brodwick, M. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Russell, J. M.
Right arrow Articles by Brodwick, M. S.
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 82, 47-78, Copyright © 1983 by The Rockefeller University Press

ARTICLES

Intracellular pH and Na fluxes in barnacle muscle with evidence for reversal of the ionic mechanism of intracellular pH regulation

JM Russell, WF Boron and MS Brodwick

The ion transport mechanism that regulates intracellular pH (pHi) in giant barnacle muscle fibers was studied by measuring pHi and unidirectional Na+ fluxes in internally dialyzed fibers. The overall process normally results in a net acid extrusion from the cell, presumably by a membrane transport mechanism that exchanges external Na+ and HCO-3 for internal Cl- and possibly H+. However, we found that net transport can be reversed either by lowering [HCO-3]o and pHo or by reducing [Na+]o. This reversal (acid uptake) required external Cl-, was stimulated by raising [Na+]i, and was blocked by SITS. When the transporter was operating in the net forward direction (acid extrusion), we found a unidirectional Na+ influx of approximately 60 pmol . cm-2 . s-1, which required external HCO-3 and internal Cl- and was stimulated by cyclic AMP and blocked by SITS or DIDS. These properties of the Na+ influx are all shared with the net acid extrusion process. We also found that under conditions of net forward transport, the pHi-regulating system mediated a unidirectional Na+ efflux, which was significantly smaller than the simultaneous Na+ influx. These data are consistent with a reversible transport mechanism which, even when operating in the net forward direction, mediates a small amount of reversed transport. We also found that the ouabain-sensitive Na+ efflux was sharply inhibited by acidic pHi, being totally absent at pHi values below approximately 6.8.
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
 Physiol. GenomicsHome page
M. D. Parker, P. Bouyer, C. M. Daly, and W. F. Boron
Cloning and characterization of novel human SLC4A8 gene products encoding Na+-driven Cl-/HCO3- exchanger variants NDCBE-A, -C, and -D
Physiol Genomics, August 1, 2008; 34(3): 265 - 276.
[Abstract] [Full Text] [PDF]

Home page
 Adv. Physiol. Educ.Home page
W. F. Boron
Regulation of intracellular pH
Advan Physiol Educ, December 1, 2004; 28(4): 160 - 179.
[Abstract] [Full Text] [PDF]


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