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PMID: 2442350 Published · ppublish English Journal Article Research Support, Non-U.S. Gov't

On the mechanism by which changes in extracellular pH affect the electrical activity of the rabbit sino-atrial node.

The Journal of physiology ·Vol. 381 ·1986-12-00 ·Pages 181-91

Satoh H, Seyama I

Abstract

1. The effect of altering the extracellular pH (pHo) on the electrical activity of the isolated rabbit sino-atrial (s.a.) node was studied using the two-micro-electrode voltage-clamp technique. 2. Alkalinization of the perfusate increased the maximum rate of rise and amplitude of the nodal action potential, and also the frequency of spontaneous beating of the s.a. node; acidification produced opposite effects. 3. A change in the extracellular pH from a value of 6.5 to 8.5 caused increases of the maximal conductance for both the slow inward current and the steady-state outward current systems without affecting the gating processes of the channels. 4. H+ could modify the electrical activity of s.a. nodal cells, not through altering the membrane surface potential but through the protonation of the ionic channels themselves. From the titration curves, the apparent pKa values for the slow inward current and the steady-state outward current were estimated to be 6.4 and 6.0, respectively.

MeSH Terms
Action Potentials Animals Female Hydrogen-Ion Concentration In Vitro Techniques Ion Channels/physiology Male Rabbits Sinoatrial Node/physiology Time Factors
Chemicals
Ion Channels
Authors & Affiliations
2 authors, click to expand affiliations / ORCID
Satoh H
Seyama I
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34 references, click to expand
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Article Info
Journal
The Journal of physiology
Abbr.
J Physiol
ISSN
0022-3751
DOI
10.1113/jphysiol.1986.sp016321
Published
1986-12-00
Pages
181-91
Language
English
Region
England
NLM ID
0266262
PMCID
PMC1182973
Subset
IM
External Links
PubMed source DOI: 10.1113/jphysiol.1986.sp016321 PMC Full Text View journal details
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