Abstract
1. An attempt was made to analyse further the factors which might determine the time course of the falling phase of the end-plate current.
2. The end-plate current was measured by `clamping' the membrane potential during neuromuscular transmission. The falling phase of the end-plate current had an exponential and a non-exponential portion.
3. The exponential portion of the falling phase of the end-plate current was found to be strongly affected by changes in the membrane potential and by relatively small changes in temperature.
4. It is suggested that the two rate constants which determine the dissociation of the receptor-mediator complex are affected by both temperature and the membrane potential. Under certain experimental conditions these two rate constants alone seem to determine the time course of the exponential portion of the falling phase of the end-plate current.
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- ALEXANDER J., WILSON I. B., KITZ R. The reactivation of acetylcholinesterase after inhibition by methanesulfonic acid esters. J Biol Chem. 1963 Feb;238:741–744. [PubMed] [Google Scholar]
- ECCLES J. C., MacFARLANE W. V. Actions of anti-cholinesterases on endplate potential of frog muscle. J Neurophysiol. 1949 Jan;12(1):59–80. doi: 10.1152/jn.1949.12.1.59. [DOI] [PubMed] [Google Scholar]
- 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]
- Gage P. W., Eisenberg R. S. Action potentials, afterpotentials, and excitation-contraction coupling in frog sartorius fibers without transverse tubules. J Gen Physiol. 1969 Mar;53(3):298–310. doi: 10.1085/jgp.53.3.298. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gage P. W., Eisenberg R. S. Capacitance of the surface and transverse tubular membrane of frog sartorius muscle fibers. J Gen Physiol. 1969 Mar;53(3):265–278. doi: 10.1085/jgp.53.3.265. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Howell J. N. A lesion of the transverse tubules of skeletal muscle. J Physiol. 1969 May;201(3):515–533. doi: 10.1113/jphysiol.1969.sp008770. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hubbard J. I., Jones S. F., Landau E. M. The effect of temperature change upon transmitter release, facilitation and post-tetanic potentiation. J Physiol. 1971 Aug;216(3):591–609. doi: 10.1113/jphysiol.1971.sp009542. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Kordas M. The effect of procaine on neuromuscular transmission. J Physiol. 1970 Aug;209(3):689–699. doi: 10.1113/jphysiol.1970.sp009186. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Maeno T., Edwards C., Hashimura S. Difference in effects of end-plate potentials between procaine and lidocaine as revealed by voltage-clamp experiments. J Neurophysiol. 1971 Jan;34(1):32–46. doi: 10.1152/jn.1971.34.1.32. [DOI] [PubMed] [Google Scholar]
- Steinbach A. B. A kinetic model for the action of xylocaine on receptors for acetylcholine. J Gen Physiol. 1968 Jul;52(1):162–180. doi: 10.1085/jgp.52.1.162. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Steinbach A. B. Alteration by xylocaine (lidocaine) and its derivatives of the time course of the end plate potential. J Gen Physiol. 1968 Jul;52(1):144–161. doi: 10.1085/jgp.52.1.144. [DOI] [PMC free article] [PubMed] [Google Scholar]
- TAKEUCHI A., TAKEUCHI N. Active phase of frog's end-plate potential. J Neurophysiol. 1959 Jul;22(4):395–411. doi: 10.1152/jn.1959.22.4.395. [DOI] [PubMed] [Google Scholar]
- TAKEUCHI N. The effect of temperature on the neuromuscular junction of the frog. Jpn J Physiol. 1958 Dec 20;8(4):391–404. doi: 10.2170/jjphysiol.8.391. [DOI] [PubMed] [Google Scholar]
- Werman R. An electrophysiological approach to drug-receptor mechanisms. Comp Biochem Physiol. 1969 Sep 15;30(6):997–1017. doi: 10.1016/0010-406x(69)91038-x. [DOI] [PubMed] [Google Scholar]