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. 1975 Jun 1;65(6):751–767. doi: 10.1085/jgp.65.6.751

Ionic properties of the acetylcholine receptor in cultured rat myotubes

PMCID: PMC2214888  PMID: 460

Abstract

The acetylcholine reversal potential (Er) of cultured rat myotubes is - 3mV. When activated, the receptor is permeable to K+ and Na+, but not to Cl- ions. Measurement of Er in Tris+-substituted, Na-free medium also indicated a permeability to Tris+ ions. Unlike adult frog muscle the magnitude of Er was insensitive to change in external Ca++ (up to 30 mM) or to changes in external pH (between 6.4 and 8.9). The equivalent circuit equation describing the electrical circuit composed of two parallel ionic batteries (EK and ENa) and their respective conductances (gK and gNa), which has been generally useful in describing the Er of adult rat and frog muscle, could also be applied to rat myotubes when Er was measured over a wide range of external Na+ concentrations. The equivalent circuit equation could not be applied to myotubes bathed in media of different external K+ concentrations. In this case, the Er was more closely described by the Goldman constant field equation. Under certain circumstances, it is known that the receptor in adult rat and frog muscle can be induced to reversibly shift from behavior described by the equivalent circuit equation to that described by the Goldman equation. Attempts to similarly manipulate the responses of cultured rat myotubes were unsussessful. These trials included a reduction in temperature (15 degress C), partial alpha-bungarotoxin blodkade, and activation of responses with the cholinergic agonist, decamethonium.

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Selected References

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

  1. AXELSSON J., THESLEFF S. A study of supersensitivity in denervated mammalian skeletal muscle. J Physiol. 1959 Jun 23;147(1):178–193. doi: 10.1113/jphysiol.1959.sp006233. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Anderson C. R., Stevens C. F. Voltage clamp analysis of acetylcholine produced end-plate current fluctuations at frog neuromuscular junction. J Physiol. 1973 Dec;235(3):655–691. doi: 10.1113/jphysiol.1973.sp010410. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bregestovski P. D., Chailachjan L. M., Dunin-Barkovski V. L., Potapova T. W., Veprintsev B. N. Effect of temperature on the equilibrium endplate potential. Nature. 1972 Apr 28;236(5348):453–454. doi: 10.1038/236453a0. [DOI] [PubMed] [Google Scholar]
  4. DIAMOND J., MILEDI R. A study of foetal and new-born rat muscle fibres. J Physiol. 1962 Aug;162:393–408. doi: 10.1113/jphysiol.1962.sp006941. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Dunin-Barkovskii V. L., Kovalev S. A., Magazanik L. G., Potapova T. V., Chailakhian L. M. Potentsialy ravnovesiia postsinapticheskoi membrany, aktivirovannoi razlichnymi kholinomineikami, pri izmenenii vnekletochnoi ionnoi sredy. Biofizika. 1969 May-Jun;14(3):485–494. [PubMed] [Google Scholar]
  6. Fambrough D., Rash J. E. Development of acetylcholine sensitivity during myogenesis. Dev Biol. 1971 Sep;26(1):55–68. doi: 10.1016/0012-1606(71)90107-2. [DOI] [PubMed] [Google Scholar]
  7. Feltz A., Mallart A. Ionic permeability changes induced by some cholinergic agonists on normal and denervated frog muscles. J Physiol. 1971 Oct;218(1):101–116. doi: 10.1113/jphysiol.1971.sp009606. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Fischbach G. D., Nameroff M., Nelson P. G. Electrical properties of chick skeletal muscle fibers developing in cell culture. J Cell Physiol. 1971 Oct;78(2):289–299. doi: 10.1002/jcp.1040780218. [DOI] [PubMed] [Google Scholar]
  9. Fischbach G. D. Synapse formation between dissociated nerve and muscle cells in low density cell cultures. Dev Biol. 1972 Jun;28(2):407–429. doi: 10.1016/0012-1606(72)90023-1. [DOI] [PubMed] [Google Scholar]
  10. Gage P. W., Armstrong C. M. Miniature end-plate currents in voltage-clamped muscle fibre. Nature. 1968 Apr 27;218(5139):363–365. doi: 10.1038/218363b0. [DOI] [PubMed] [Google Scholar]
  11. Grundfest H. Some comparative biological aspects of membrane permeability control. Fed Proc. 1967 Nov-Dec;26(6):1613–1626. [PubMed] [Google Scholar]
  12. Harris J. B., Marshall M. W., Wilson P. A physiological study of chick myotubes grown in tissue culture. J Physiol. 1973 Mar;229(3):751–766. doi: 10.1113/jphysiol.1973.sp010165. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Hille B. The permeability of the sodium channel to organic cations in myelinated nerve. J Gen Physiol. 1971 Dec;58(6):599–619. doi: 10.1085/jgp.58.6.599. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. JENKINSON D. H., NICHOLLS J. G. Contractures and permeability changes produced by acetylcholine in depolarized denervated muscle. J Physiol. 1961 Nov;159:111–127. doi: 10.1113/jphysiol.1961.sp006796. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Katz B., Miledi R. The characteristics of 'end-plate noise' produced by different depolarizing drugs. J Physiol. 1973 May;230(3):707–717. doi: 10.1113/jphysiol.1973.sp010213. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Katz B., Miledi R. The effect of alpha-bungarotoxin on acetylcholine receptors. Br J Pharmacol. 1973 Sep;49(1):138–139. doi: 10.1111/j.1476-5381.1973.tb08278.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Katz B., Miledi R. The statistical nature of the acetycholine potential and its molecular components. J Physiol. 1972 Aug;224(3):665–699. doi: 10.1113/jphysiol.1972.sp009918. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Kordas M. The effect of membrane polarization on the time course of the end-plate current in frog sartorius muscle. J Physiol. 1969 Oct;204(2):493–502. doi: 10.1113/jphysiol.1969.sp008926. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Maeno T. Analysis of sodium and potassium conductances in the procaine end-plate potential. J Physiol. 1966 Apr;183(3):592–606. doi: 10.1113/jphysiol.1966.sp007886. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Magazanik L. G., Potapova T. V. Potentsialy ravnovesiia vnesinapticheskoi membrany denervirovannoi myshtsy pri izmenenii vnekletochnoi ionnoi sredy. Biofizika. 1969 Jul-Aug;14(4):658–662. [PubMed] [Google Scholar]
  21. Magazanik L. G., Vyskocil F. Some characteristics of end-plate potentials after partial blockade by -bungarotoxin in Rana temporaria. Experientia. 1973 Feb 15;29(2):157–158. doi: 10.1007/BF01945446. [DOI] [PubMed] [Google Scholar]
  22. Magleby K. L., Stevens C. F. A quantitative description of end-plate currents. J Physiol. 1972 May;223(1):173–197. doi: 10.1113/jphysiol.1972.sp009840. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Mallart A., Trautmann A. Ionic properties of the neuromuscular junction of the frog: effects of denervation and pH. J Physiol. 1973 Nov;234(3):553–567. doi: 10.1113/jphysiol.1973.sp010360. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Sachs F., Lecar H. Acetylcholine noise in tissue culture muscle cells. Nat New Biol. 1973 Dec 19;246(155):214–216. doi: 10.1038/newbio246214a0. [DOI] [PubMed] [Google Scholar]

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