Abstract
In nerve membrane, the non-linear capacity current (displacement current) is assumed to reflect the movement of intrinsic membrane charges which control the opening of specific pathways for sodium ions (Na channels). However, various discrepancies have been reported between the effects of pharmacological agents on sodium and displacement currents (for a review see ref. 1). It is generally supposed that the opening and closing of Na channels constitutes one step of a multi-step system in which each configuration change may or not give rise to a measurable charge movement2. New drugs affecting either sodium or displacement currents may elucidate the relationship between charge movement and the control of sodium conductance. We therefore now report a comparison of the effects of a vegetable toxin (oenanthotoxin or OETX)3 on both sodium current (INa) and intra-membrane charge movement (Q) in Ranvier nodes. We show that OETX reversibly blocks both sodium and displacement current. Studies of INa and Q during partial suppression by the toxin reveal differences in the effects of OETX on the remaining INa and Q. The findings are discussed in relation to recent models for the Na-channel gating process and for Na-channel block by local anaesthetics.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Almers, W. Rev. Physiol. Biochem. Pharmac. 82, 96–190 (1978).
Armstrong, C. M. & Bezanilla, F. J. gen. Physiol. 70, 567–590 (1977).
Anger, J. P. et al. Eur. J. Tox. 9, 119–125 (1976).
Grundy, H. F. & Howarth, F. Br. J. Pharmac. 11, 225–230 (1956).
Chauvel, P., Louvel, J., Anger, J. P. & Chauvel, Y. C. r. hebd. Acad. Sci. Séance, Paris 286, 1833–1836 (1978).
Dubois, J. M. & Bergman, C. Pflügers Arch. ges. Physiol. 370, 185–194 (1977).
Nonner, W., Rojas, E. & Stämpfli, R. Pflügers Arch. ges. Physiol. 375, 75–85 (1978).
Khodorov, B., Shishkova, L., Peganov, E. & Revenko, S. Biochim. biophys. Acta 433, 409–435 (1976).
Dubois, J. M. & Schneider, M. F. Adv. physiol. Sci. (in the press).
Drouin, H. & Neumcke, B. Pflügers Arch. ges. Physiol. 351, 207–229 (1974).
Neumcke, B., Nonner, W. & Stämpfli, R. Pflügers Arch. ges. Physiol. 363, 193–203 (1976).
Chiu, S. Y. J. Physiol., Lond. 273, 573–596 (1977).
Hille, B. J. gen. Physiol. 69, 497–515 (1977).
Khodorov, B., Guselnikova, G. & Peganov, E. Dokl. Acad. Nauk SSSR 244, 1252–1255 (1979).
Arhem, P. & Frankenhaeuser, B. Acta physiol. scand. 91, 11–21 (1974).
Hille, B. J. gen. Physiol. 69, 475–496 (1977).
Armstrong, C. M. & Gilly, W. F. J. gen. Physiol. 74, 691–711 (1979).
Nonner, W. J. Physiol., Lond. 299, 573–603 (1980).
Dodge, F. A. & Frankenhaeuser, B. J. Physiol., Lond. 148, 188–200 (1959).
Schneider, M. F. & Chandler, W. K. Nature 242, 244–246 (1973).
Keynes, R. D. & Rojas, E. J. Physiol., Lond. 239, 393–434 (1974).
Nonner, W., Rojas, E. & Stämpfli, R. Pflügers Arch. ges. Physiol. 354, 1–18 (1975).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Dubois, J., Schneider, M. Block of Na current and intramembrane charge movement in myelinated nerve fibres poisoned with a vegetable toxin. Nature 289, 685–688 (1981). https://doi.org/10.1038/289685a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/289685a0
This article is cited by
-
Batrachotoxin protects sodium channels from the blocking action of oenanthotoxin
Pfl�gers Archiv European Journal of Physiology (1982)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.