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. 1984 Aug;46(2):277–283. doi: 10.1016/S0006-3495(84)84022-9

Agonists block currents through acetylcholine receptor channels.

S M Sine, J H Steinbach
PMCID: PMC1435044  PMID: 6478036

Abstract

We have examined the effects of high concentrations of cholinergic agonists on currents through single acetylcholine receptor (AChR) channels on clonal BC3H1 cells. We find that raised concentrations of acetylcholine (ACh; above 300 microM) or carbamylcholine (Carb; above 1,000 microM) produce a voltage- and concentration-dependent reduction in the mean single-channel current. Raised concentrations of suberyldicholine (Sub; above 3 microM) produce a voltage- and concentration-dependent increase in the number of brief duration low-conductance interruptions of open-channel currents. These observations can be quantitatively described by a model in which agonist molecules enter and transiently occlude the ion-channel of the AChR.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Adams D. J., Nonner W., Dwyer T. M., Hille B. Block of endplate channels by permeant cations in frog skeletal muscle. J Gen Physiol. 1981 Dec;78(6):593–615. doi: 10.1085/jgp.78.6.593. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Adams P. R., Sakmann B. Decamethonium both opens and blocks endplate channels. Proc Natl Acad Sci U S A. 1978 Jun;75(6):2994–2998. doi: 10.1073/pnas.75.6.2994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Creese R., England J. M. Decamethonium in depolarized muscle and the effects of tubocurarine. J Physiol. 1970 Sep;210(2):345–361. doi: 10.1113/jphysiol.1970.sp009214. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. French R. J., Wells J. B. Sodium ions as blocking agents and charge carriers in the potassium channel of the squid giant axon. J Gen Physiol. 1977 Dec;70(6):707–724. doi: 10.1085/jgp.70.6.707. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Hamill O. P., Marty A., Neher E., Sakmann B., Sigworth F. J. Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflugers Arch. 1981 Aug;391(2):85–100. doi: 10.1007/BF00656997. [DOI] [PubMed] [Google Scholar]
  6. Hille B., Schwarz W. Potassium channels as multi-ion single-file pores. J Gen Physiol. 1978 Oct;72(4):409–442. doi: 10.1085/jgp.72.4.409. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Miller C. Bis-quaternary ammonium blockers as structural probes of the sarcoplasmic reticulum K+ channel. J Gen Physiol. 1982 May;79(5):869–891. doi: 10.1085/jgp.79.5.869. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Neher E., Steinbach J. H. Local anaesthetics transiently block currents through single acetylcholine-receptor channels. J Physiol. 1978 Apr;277:153–176. doi: 10.1113/jphysiol.1978.sp012267. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Sakmann B., Patlak J., Neher E. Single acetylcholine-activated channels show burst-kinetics in presence of desensitizing concentrations of agonist. Nature. 1980 Jul 3;286(5768):71–73. doi: 10.1038/286071a0. [DOI] [PubMed] [Google Scholar]
  10. Schubert D., Harris A. J., Devine C. E., Heinemann S. Characterization of a unique muscle cell line. J Cell Biol. 1974 May;61(2):398–413. doi: 10.1083/jcb.61.2.398. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Sine S. M., Steinbach J. H. Activation of a nicotinic acetylcholine receptor. Biophys J. 1984 Jan;45(1):175–185. doi: 10.1016/S0006-3495(84)84146-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Sine S. M., Taylor P. Relationship between reversible antagonist occupancy and the functional capacity of the acetylcholine receptor. J Biol Chem. 1981 Jul 10;256(13):6692–6699. [PubMed] [Google Scholar]
  13. Sine S. M., Taylor P. The relationship between agonist occupation and the permeability response of the cholinergic receptor revealed by bound cobra alpha-toxin. J Biol Chem. 1980 Nov 10;255(21):10144–10156. [PubMed] [Google Scholar]
  14. Sine S., Taylor P. Functional consequences of agonist-mediated state transitions in the cholinergic receptor. Studies in cultured muscle cells. J Biol Chem. 1979 May 10;254(9):3315–3325. [PubMed] [Google Scholar]
  15. Stevens C. F. Interactions between intrinsic membrane protein and electric field. An approach to studying nerve excitability. Biophys J. 1978 May;22(2):295–306. doi: 10.1016/S0006-3495(78)85490-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Trautmann A. Curare can open and block ionic channels associated with cholinergic receptors. Nature. 1982 Jul 15;298(5871):272–275. doi: 10.1038/298272a0. [DOI] [PubMed] [Google Scholar]
  17. Woodhull A. M. Ionic blockage of sodium channels in nerve. J Gen Physiol. 1973 Jun;61(6):687–708. doi: 10.1085/jgp.61.6.687. [DOI] [PMC free article] [PubMed] [Google Scholar]

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