Abstract
Neutral carrier based sodium-selective microelectrodes were used to monitor intracellular sodium activity in single frog skeletal muscle fibres during exposure to 50% external sodium solutions at normal and twice normal tonicity.
Intracellular sodium activity in normal Ringer was 12.3±0.7 mM and was increased to 34.4±1.3mM in hypertonic solution.
Exposure to normotonic or hypertonic solutions containing only 50% sodium (NaCl replaced by sucrose to maintain tonicity) did not affect the intracellular sodium activity during at least 20 min. Thus, in frog skeletal muscle, external sodium appears not to play a major role in regulating internal sodium, e.g. throught ion exchange mechanisms as postulated for other excitable tissues.
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References
Armstrong WMcD, Lee CO (1971) Sodium and potassium activities in normal and “sodium-rich” frog skeletal muscle. Science 171:413–415
Baylor SM, Oetliker H (1977) Birefringence signals from surface and T-system membranes of frog single skeletal muscle fibres. J Physiol 264:199–213
Blaustein MP (1974) The interrelationship between sodium and calcium fluxes across cell membranes. Rev Physiol Biochem Pharmacol 70:33–82
Chapman RA, Coray A, McGuigan JAS (in press) Sodium/calcium exchange in mammalien ventricular muscle. J Physiol
Coulombe A, Schanne OF, Reisin I, Ruiz-Ceretti E (1980) Effects of amphotericin B on the electrical properties and electrolyte content of frog sartorius muscle. Can J Physiol Pharmacol 58:1138–1141
Dydynska M, Wilkie DR (1963) The osmotic properties of striated muscle fibres in hypertonic solutions. J Physiol 169:312–329
Edelmann L (1980) Preferential localized uptake of K+ and Cs+ over Na+ in the A-band of freeze-dried embedded muscle sections: Detection by x-ray microanalysis and laser microprobe mass analysis. Physiol Chem Phys 12:509–514
Ellis D (1977) The effects of external cations and ouabain on the intracellular sodium activity of sheep heart Purkinje fibres. J Physiol 273:211–240
Fujimoto M, Honda M (1980) A triple barreled microelectrode for simultaneous measurements of intracellular Na+ and K+ activities and membrane potential in biological cells. Jpn J Physiol 30:859–875
Hodgkin AL, Horowicz P (1959a) Movements of Na and K in single muscle fibers. J Physiol 145:405–432
Hodgkin AL, Horowicz P (1959b) The influence of potassium and chloride ions on the membrane potential of single muscle fibres. J Physiol 148:127–160
Hodgkin AL, Keynes RD (1956) Experiments on the injection of substances into giant axons by means of a microsyringe. J Physiol 131:592–616
Keynes RD, Swan RC (1959) The effect of external sodium concentration on the sodium fluxes in frog skeletal muscle. J Physiol 147:591–624
Kushmerick MJ, Podolsky RJ (1969) Ionic mobility in muscle cells. Science 166:1297–1298
Lee CO, Armstrong WMcD (1974) State and distribution of potassium and sodium ions in frog skeletal muscle. J Membr Biol 15:331–362
Lev AA (1964) Determination of activity and activity coefficients of potassium and sodium ions in frog muscle fibres. Nature 201:1132–1134
Ling GN (1980) Underestimation of the Na permeability in muscle cells: Implications for the theory of cell potential and for energy requirements of the Na pump. Physiol Chem Phys 12:215–232
McLaughlin SGA, Hinke JAM (1968) Optical density changes of single muscle fibres in sodium free solutions. Can J Physiol Pharmacol 46:247–260
Mullins LJ (1981) Ion transport in heart. Raven Press, New York
Neville MC, White S (1979) Extracellular space of frog skeletal muscle in vivo and in vitro: Relation to proton magnetic resonance relaxation time. J Physiol 288:71–83
Robinson RA, Stokes RH (1970) Electrolyte solutions. Butterworth, London, 2nd edn, 5th impression, p 492
Shvinka NE (1980) Effect of glycerol treatment on sodium and potassium in isolated muscle fibres of the frog. Experientia 36:433–434
Sjodin RA (1971) The kinetics of sodium extrusion in striated muscle as functions of the external sodium and potassium ion concentrations. J Gen Physiol 57:164–187
Sjodin RA, Beaugé LA (1973) An analysis of the leakages of sodium ions into and potassium ions out of striated muscle cells. J Gen Physiol 61:222–250
Somlyo AV, Shuman H, Somlyo AP (1977) Elemental distribution in striated muscle and effects of hypertonicity. Electron probe analysis of cryo sections. J Cell Biol 74:828–857
Steiner RA, Oehme M, Ammann D, Simon W (1979) Neutral carrier sodium ion-selective microelectrodes for intracellular studies. Anal Chem 51:351–353
Tsien RY, Rink TJ (1980) Neutral carrier based ion-selective microelectrodes for measurement of intracellular free calcium. Biochim Biophys Acta 599:623–638
Vaughan-Jones RD (1977) The effect of lowering external sodium on the intracellular sodium activity of crab muscle fibres. J Physiol 264:239–266
White JF, Hinke JAM (1976) Use of the sodium microelectrode to define sodium efflux and the behaviour of the sodium pump in the frog sartorius. In: Kessler M, Clark LC, Lübbers DW, Silver IA, Simon W (eds) Ion and enzyme electrodes in biology and medicine. Urban & Schwarzenberg, München Berlin Wien, p 355
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Schümperli, R.A., Oetliker, H. & Weingart, R. Effect of 50% external sodium in solutions of normal and twice normal tonicity on internal sodium activity in frog skeletal muscle. Pflugers Arch. 393, 51–55 (1982). https://doi.org/10.1007/BF00582391
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DOI: https://doi.org/10.1007/BF00582391