Abstract
1. Current and voltage clamp experiments were carried out on frog skeletal muscle fibres. For voltage clamp, the three micro-electrode technique near the fibre end was used. 2. Calcium spikes and currents were recorded in TEA sulphate saline. The addition of 400 mM-glycerol did not appreciably modify them. 3. Muscle fibers were detubulated with the glycerol method. They showed sodium propagating action potentials, with sodium and potassium currents of expected amplitudes. 4. Calcium spikes and currents were reduced or abolished in detubulated muscle fibres. 5. An analysis of fibre capacitance showed a linear correlation between the remaining ICa and the degree of electric discontinuity between the transverse tubular system and the surface membrane. 6. These results indicate that ICa is mainly located in the transverse tubular system. This localization is compatible with some role during mechanical activation.
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- Adrian R. H., Almers W. Charge movement in the membrane of striated muscle. J Physiol. 1976 Jan;254(2):339–360. doi: 10.1113/jphysiol.1976.sp011235. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Adrian R. H., Chandler W. K., Hodgkin A. L. Voltage clamp experiments in striated muscle fibres. J Physiol. 1970 Jul;208(3):607–644. doi: 10.1113/jphysiol.1970.sp009139. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Almers W. Gating currents and charge movements in excitable membranes. Rev Physiol Biochem Pharmacol. 1978;82:96–190. doi: 10.1007/BFb0030498. [DOI] [PubMed] [Google Scholar]
- Beaty G. N., Stefani E. Calcium dependent electrical activity in twitch muscle fibres of the frog. Proc R Soc Lond B Biol Sci. 1976 Aug 27;194(1114):141–150. doi: 10.1098/rspb.1976.0070. [DOI] [PubMed] [Google Scholar]
- Chandler W. K., Rakowski R. F., Schneider M. F. Effects of glycerol treatment and maintained depolarization on charge movement in skeletal muscle. J Physiol. 1976 Jan;254(2):285–316. doi: 10.1113/jphysiol.1976.sp011233. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chiarandini D. J., Stefani E. Twitch potentiation by potassium contractures in single muscle fibres of the frog. J Physiol. 1974 Jul;240(1):1–14. doi: 10.1113/jphysiol.1974.sp010595. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dulhunty A. F., Gage P. W. Differential effects of glycerol treatment on membrane capacity and excitation-contraction coupling in toad sartorius fibres. J Physiol. 1973 Oct;234(2):373–408. doi: 10.1113/jphysiol.1973.sp010350. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eisenberg B., Eisenberg R. S. Selective disruption of the sarcotubular system in frog sartorius muscle. A quantitative study with exogenous peroxidase as a marker. J Cell Biol. 1968 Nov;39(2):451–467. doi: 10.1083/jcb.39.2.451. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eisenberg R. S., Gage P. W. Ionic conductances of the surface and transverse tubular membranes of frog sartorius fibers. J Gen Physiol. 1969 Mar;53(3):279–297. doi: 10.1085/jgp.53.3.279. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eisenberg R. S., Howell J. N., Vaughan P. C. The maintenance of resting potentials in glycerol-treated muscle fibres. J Physiol. 1971 May;215(1):95–102. doi: 10.1113/jphysiol.1971.sp009459. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FREYGANG W. H., Jr, GOLDSTEIN D. A., HELLAM D. C., PEACHEY L. D. THE RELATION BETWEEN THE LATE AFTER-POTENTIAL AND THE SIZE OF THE TRANSVERSE TUBULAR SYSTEM OF FROG MUSCLE. J Gen Physiol. 1964 Nov;48:235–263. doi: 10.1085/jgp.48.2.235. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FUJINO M., YAMAGUCHI T., SUZUKI K. 'Glycerol effect' and the mechanism linking excitation of the plasma membrane with contraction. Nature. 1961 Dec 23;192:1159–1161. doi: 10.1038/1921159a0. [DOI] [PubMed] [Google Scholar]
- Fink R., Lüttgau H. C. An evaluation of the membrane constants and the potassium conductance in metabolically exhausted muscle fibres. J Physiol. 1976 Dec;263(2):215–238. doi: 10.1113/jphysiol.1976.sp011629. [DOI] [PMC free article] [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]
- Hodgkin A. L., Nakajima S. Analysis of the membrane capacity in frog muscle. J Physiol. 1972 Feb;221(1):121–136. doi: 10.1113/jphysiol.1972.sp009743. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kirsch G. E., Nichols R. A., Nakajima S. Delayed rectification in the transverse tubules: origin of the late after-potential in frog skeletal muscle. J Gen Physiol. 1977 Jul;70(1):1–21. doi: 10.1085/jgp.70.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Meech R. W., Standen N. B. Potassium activation in Helix aspersa neurones under voltage clamp: a component mediated by calcium influx. J Physiol. 1975 Jul;249(2):211–239. doi: 10.1113/jphysiol.1975.sp011012. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Peachey L. D., Schild R. F. The distribution of the T-system along the sarcomeres of frog and toad sartorius muscles. J Physiol. 1968 Jan;194(1):249–258. doi: 10.1113/jphysiol.1968.sp008405. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Potreau D., Raymond G. Slow inward calcium current and contraction on frog single muscle fibres [proceedings]. J Physiol. 1978 Sep;282:17P–18P. [PubMed] [Google Scholar]
- Sanchez J. A., Stefani E. Inward calcium current in twitch muscle fibres of the frog. J Physiol. 1978 Oct;283:197–209. doi: 10.1113/jphysiol.1978.sp012496. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schneider M. F., Chandler W. K. Voltage dependent charge movement of skeletal muscle: a possible step in excitation-contraction coupling. Nature. 1973 Mar 23;242(5395):244–246. doi: 10.1038/242244a0. [DOI] [PubMed] [Google Scholar]
- Schneider M. F. Linear electrical properties of the transverse tubules and surface membrane of skeletal muscle fibers. J Gen Physiol. 1970 Nov;56(5):640–671. doi: 10.1085/jgp.56.5.640. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stanfield P. R. A calcium dependent inward current in frog skeletal muscle fibres. Pflugers Arch. 1977 Apr 25;368(3):267–270. doi: 10.1007/BF00585206. [DOI] [PubMed] [Google Scholar]
- Stefani E., Chiarandini D. J. Skeletal muscle: dependence of potassium contractures on extracellular calcium. Pflugers Arch. 1973 Oct 17;343(2):143–150. doi: 10.1007/BF00585709. [DOI] [PubMed] [Google Scholar]