The Journal of General Physiology
Cell MicroControls
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text (PDF, 897K)
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 Narahashi, T.
Right arrow Articles by Deguchi, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Narahashi, T.
Right arrow Articles by Deguchi, T.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?
The Journal of General Physiology, Vol 58, 54-70, Copyright © 1971 by The Rockefeller University Press

ARTICLE

Effects of Batrachotoxin on Membrane Potential and Conductance of Squid Giant Axons

Toshio Narahashi 1, Edson X. Albuquerque 1, and Takehiko Deguchi 1

1 From the Department of Physiology and Pharmacology, Duke University Medical Center, Durham, North Carolina 27710, and the Department of Pharmacology, State University of New York at Buffalo, Buffalo, New York 14214.

Dr. Deguchi's present address is Central Research Laboratories, Sankyo Co., Ltd., Schinagawa-Ku, Tokyo, Japan.

The effects of batrachotoxin (BTX) on the membrane potential and conductances of squid giant axons have been studied by means of intracellular microelectrode recording, internal perfusion, and voltage clamp techniques. BTX (550–1100 nM) caused a marked and irreversible depolarization of the nerve membrane, the membrane potential being eventually reversed in polarity by as much as 15 mv. The depolarization progressed more rapidly with internal application than with external application of BTX to the axon. External application of tetrodotoxin (1000 nM) completely restored the BTX depolarization. Removal or drastic reduction of external sodium caused a hyperpolarization of the BTX-poisoned membrane. However, no change in the resting membrane potential occurred when BTX was applied in the absence of sodium ions in both external and internal phases. These observations demonstrate that BTX specifically increases the resting sodium permeability of the squid axon membrane. Despite such an increase in resting sodium permeability, the BTX-poisoned membrane was still capable of undergoing a large sodium permeability increase of normal magnitude upon depolarizing stimulation provided that the membrane potential was brought back to the original or higher level. The possibility that a single sodium channel is operative for both the resting sodium, permeability and the sodium permeability increase upon stimulation is discussed.

Submitted on February 2, 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 Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:


Home page
 J. Pharmacol. Exp. Ther.Home page
T. Narahashi
Neuroreceptors and Ion Channels as the Basis for Drug Action: Past, Present, and Future
J. Pharmacol. Exp. Ther., July 1, 2000; 294(1): 1 - 26.
[Abstract] [Full Text]

Home page
 J. Biol. Chem.Home page
V. L. Trainer, G. B. Brown, and W. A. Catterall
Site of Covalent Labeling by a Photoreactive Batrachotoxin Derivative near Transmembrane Segment IS6 of the Sodium Channel alpha Subunit
J. Biol. Chem., May 10, 1996; 271(19): 11261 - 11267.
[Abstract] [Full Text] [PDF]

Home page
 ScienceHome page
S Ochs and R Worth
Batrachotoxin block of fast axoplasmic transport in mammalian nerve fibers
Science, March 21, 1975; 187(4181): 1087 - 1089.
[Abstract] [PDF]


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