help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS

Biophysical Journal 35: 393-413 (1981)
© 1981 the Biophysical Society

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Carbone, E
Right arrow Articles by Wanke, E
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Carbone, E
Right arrow Articles by Wanke, E

Intracellular pH and ionic channels in the Loligo vulgaris giant axon.

E Carbone, P L Testa and E Wanke

ABSTRACT

Squid giant axons were used to investigate the reversible effects of intracellular pH(pHi) on the kinetic properties of ionic channels. The pharmacologically separated K+ and Na+ currents were measured under: (a) internal perfusion, (b) enzymatic Pronase treatment, and (c) continuous estimate of periaxonal ion accumulation. Variation of internal pH from 4.8 to 11 resulted in: (a) a decrease of steady-state sodium inactivation at positive potentials similar to the effect of the proteolytic enzyme Pronase, (b) a shift of the h infinity (E) curve toward depolarizing voltages, and (c) a decrease of the time constant of inactivation for potentials below -20 mV (an increase above). A plot of the steady-state sodium conductance at E = +40 mV as a function of pHi suggests that two groups with pKa 10.4 and 5.6 affect respectively the inactivation gate and the rate constants for the transition from the inactivated to the second open state (h2) (Chandler and Meves, 1970b). The voltage shifts of the kinetic parameters predicted by the Gouy-Chapman-Stern theory are well satisfied at high pHi and less at low. Once corrected for voltage shifts, the forward rate constants for channel opening were found to be slowed with the acidity of the internal or external solution.




This article has been cited by other articles:


Home page
 J. Neurophysiol.Home page
G. C. Tombaugh
Intracellular pH Buffering Shapes Activity-Dependent Ca2+ Dynamics in Dendrites of CA1 Interneurons
J Neurophysiol, October 1, 1998; 80(4): 1702 - 1712.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1981 by the Biophysical Society.