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Calcium movement in nerve fibres

Published online by Cambridge University Press:  17 March 2009

J. Requena
Affiliation:
Centro de Biofisica y Bioquimica, Instituto Venezolano de Investigaciones Cientificas (IVIC), Apartado 1827, Caracas 101, Venezuela, and Department of Biophysics, School of Medicine University of Maryland, Baltimore, Md., 21201, U.S.A.
L. J. Mullins
Affiliation:
Centro de Biofisica y Bioquimica, Instituto Venezolano de Investigaciones Cientificas (IVIC), Apartado 1827, Caracas 101, Venezuela, and Department of Biophysics, School of Medicine University of Maryland, Baltimore, Md., 21201, U.S.A.

Extract

Given the existence of a difference in electrical potential between the interior of a nerve cell and the media surrounding it, where the cytoplasm is some 70 mV negative (Hodgkin, 1958), it must be expected that any positively charged ion to which the cell membrane is permeable is more concentrated in the cell interior. For monovalent cations such as Na and divalent cations such as Ca and Mg this is not the case in the majority of the cells such as the squid giant axon. In other words, nerve cells maintain a lower intracellular concentration of these ions, as compared with their concentration in the extracellular fluid. For Mg, Ca and Na ions, this lower internal concentration must, in the steady state, be effected by some membrane based mechanism which consumes energy.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1979

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References

Abercrombie, R. F. & Sjodin, R. A. (1977). Sodium efflux in Myxicola giant axons. J. gen. Physiol. 69, 765778.CrossRefGoogle ScholarPubMed
Alema, S., Calissano, P., Rusca, G. & Giuditta, A. (1973). Identification of a calcium-binding, brain specific protein in the axoplasm of squid giant axons. J. Neurochem. 20, 681689.CrossRefGoogle ScholarPubMed
Allen, D. G., Blinks, J. R. & Prendergast, F. G. (1977). Aequorin luminescence: Relation of light emission to calcium concentration – a calcium- independent component. Science, N.Y. 195, 996998.CrossRefGoogle ScholarPubMed
Ashley, C. C. (1978). Calcium ion regulation in barnacle muscle fibers and its relation to force development. Ann. N. Y. Acad. Sci. 307, 308329.CrossRefGoogle ScholarPubMed
Ashley, C. C. (1970). An estimate of calcium concentration changes during contraction of single muscle fibers. J. Physiol. 210, 133134P.Google Scholar
Azzi, A. & Chance, B. (1969). The ‘energized state’ of mitochondria: Lifetime and ATP equivalence. Biochem. biophys. Acta 189, 141151.Google ScholarPubMed
Baker, P. F. (1968). Recent experiments on the properties of the Na efflux from squid axons. J. gen. Physiol. 51, 17251795.CrossRefGoogle ScholarPubMed
Baker, P. F. (1970). Sodium–calcium exchange across nerve cell membrane. In Calcium and Cellular function (ed. Cuthbert, A. W.). London: Macmillan.Google Scholar
Baker, P. F. (1972). Transport and metabolism of calcium ions in nerve. Prog. Biophys. and molec. Biol. 24, 177223.CrossRefGoogle ScholarPubMed
Baker, P. F. (1976). Regulation of intracellular Ca and Mg in squid axons. Federation Proc. 35, 25892595.Google ScholarPubMed
Baker, P. F. (1978). The regulation of intracellular calcium in giant axons of Loligo and Myxicola. Ann. N.Y. Acad. Sci. 307, 250268.CrossRefGoogle ScholarPubMed
Baker, P. F. & Blaustein, M. P. (1968). Sodium-dependent uptake of calcium by crab nerve. Biochim. biophys. Acta 150, 167170.CrossRefGoogle ScholarPubMed
Baker, P. F., Blaustein, M. P., Hodgkin, A. L. & Steinhardt, R. A. (1967). The effect of sodium concentration in calcium movements in giant axons of Loligo forbesi. J. Physiol. 192, 4344P.Google Scholar
Baker, P. F., Blaustein, M. P., Hodgkin, A. L. & Steinhardt, R. A. (1969). The influence of calcium on sodium efflux in squid axons. J. Physiol. 200, 431458.CrossRefGoogle ScholarPubMed
Baker, P. F., Foster, R. F., Gilbert, D. S. & Shaw, T. I. (1971). Na transport by perfused giant axons of Loligo. J. Physiol. 219, 487506.CrossRefGoogle Scholar
Baker, P. F. & Glitsch, H. G. (1973). Does metabolic energy participate directly in the Na+ dependent extrusion of Ca2+ ions from squid giant axons? J. Physiol. 233, 4446P.Google ScholarPubMed
Baker, P. F. & Honerjager, P. (1978). Influence of CO2 on level of ionized Ca in squid axons. Nature, Lond. 273, 160161.CrossRefGoogle Scholar
Baker, P. F., Hodgkin, A. L. & Ridgway, E. G. (1971). Depolarization and calcium entry in squid axons. J. Physiol. 218, 709755.CrossRefGoogle Scholar
Baker, P. F., Meves, H. & Ridgway, E. G. (1973 a). Effects of manganase and other agents on the calcium uptake that follows depolarization of squid axons. J. Physiol. 231, 511526.CrossRefGoogle Scholar
Baker, P. F., Meves, H. & Ridgway, E. G. (1973 b). Calcium entry in response to maintained depolarization of squid axons. J. Physiol. 231, 527548.CrossRefGoogle ScholarPubMed
Baker, P. F. & McNaughton, P. A. (1976 a). Kinetics and energetics of calcium efflux from intact squid giant axons. J. Physiol. 259, 103144.CrossRefGoogle ScholarPubMed
Baker, P. F. & McNaughton, P. A. (1976 b). The effect of membrane potential on the calcium transport systems in squid axons. J. Physiol. 260, 2425P.Google ScholarPubMed
Baker, P. F. & McNaughton, P. A. (1978). The influence of extracellular calcium binding on the calcium efflux from squid axons. J. Physiol. 276, 127150.CrossRefGoogle ScholarPubMed
Baker, P. F. & Schlaepfer, W. (1975). Calcium uptake by axoplasm extruded from giant axons of Loligo. J. Physiol. 249, 3739P.Google ScholarPubMed
Baker, P. F. & Schlaepfer, W. W. (1978). Uptake and binding of calcium by axoplasm isolated from giant axons of Loligo and Myxicola. J. Physiol. 276, 103125.CrossRefGoogle ScholarPubMed
Bjerrum, J., Schwarzenbach, G. & Sillen, L. G. (1957). Stability Constants. Part x. Organic Ligands. London: The Chemical Society.Google Scholar
Blaustein, M. P. (1974). The interrelationship between sodium and calcium fluxes across cell membranes. Rev. Physiol. Biochem. Pharmacol. 70, 3382.CrossRefGoogle ScholarPubMed
Blaustein, M. P. (1976). The ins and outs of calcium transport in squid axons: internal and external ion activation of calcium efflux. Federation Proc. 35, 25142578.Google ScholarPubMed
Blaustein, M. P. (1977). Effect of internal and external cations and of ATP on sodium–calcium and calcium–calcium exchange in squid axons. Biophys. J. 20, 79111.CrossRefGoogle ScholarPubMed
Blasutein, M. P. & Hodgkin, A. L. (1969). The effect of cyanide on the efflux of calcium from squid axons. J. Physiol. 200, 497527.CrossRefGoogle Scholar
Blaustein, M. P., Ratzlaff, R. W. & Kendrick, N. K. (1978). The regulation of intracellular calcium in presynaptic nerve terminals. Ann. N. Y. Acad. Sci. 307, 195211.CrossRefGoogle ScholarPubMed
Blaustein, M. P., Ratzlaff, R. W., Kendrick, N. K. & Schweitzer, E. S. (1979). Calcium buffering in presynaptic nerve terminals. J. gen. Physiol. 72, 1541.CrossRefGoogle Scholar
Blaustein, M. P. & Russell, J. M. (1975). Sodium-calcium exchange and calcium-calcium exchange in internally dialyzed squid giant axons.J. Membrane Biol. 22, 285312.CrossRefGoogle ScholarPubMed
Blaustein, M. P., Russell, J. M. & DeWeer, P. (1974). Calcium efflux from internally dialyzed squid axons: the influence of external and internal cations. J. Supramol. Struct. 2, 558581.CrossRefGoogle ScholarPubMed
Blinks, J. R., Prendergast, F. G. & Allen, D. G. ( 1976). Photoproteins as biological calcium indicators. Pharmac. Rev. 28, 193.Google ScholarPubMed
Boron, W. F. & DeWeer, P. (1976). Intracellular pH transients in squid giant axons caused by CO2, NH3 and metabolic inhibitors. J. Gen. Physiol. 67, 91112.CrossRefGoogle ScholarPubMed
Brinley, F. J. (1978 a). Calcium buffering in squid axons. A. Rev. Biophys. Bioeng. 7, 363392.CrossRefGoogle ScholarPubMed
Brinley, F. J. Jr (1978 b). Comment on the relation between calcium entry and change in ionized calcium. Ann. N.Y. Acad. Sci. 307, 424426.CrossRefGoogle ScholarPubMed
Brinley, F. J. Jr, & Mullins, L. J. (1967). Sodium extrusion by internally dialyzed squid axons. J. gen. Physiol. 50, 23032331.CrossRefGoogle ScholarPubMed
Brinley, F. J. Jr, & Mullins, L. J. (1968). Sodium fluxes in internally dialyzed squid axons. J. gen. Physiol. 52, 181211.CrossRefGoogle ScholarPubMed
Brinley, F. J. Jr, & Mullins, L. J. (1974). Effects of membrane potential on Sodium and Potassium fluxes in squid axons. Ann. N. Y. Acad. Sci. 242, 406433.CrossRefGoogle ScholarPubMed
Brinley, F. J. Jr, Spangler, S. G. & Mullins, L. J. (1975). Calcium and EDTA fluxes in dialyzed squid axons. J. gen. Physiol. 66, 223250.CrossRefGoogle ScholarPubMed
Brinley, F. J. Jr, Tiffert, J. T. & Scarpa, A. (1978). Mitochondria and other calcium buffers of squid axons studied in situ. J. gen. Physiol. 72, 101127.CrossRefGoogle ScholarPubMed
Brinley, F. J. Jr, Tiffert, J. T., Scarpa, A. & Mullins, L. I. (1977). Intracellular calcium buffering capacity in isolated squid axons. J. gen. Physiol. 70, 355384.CrossRefGoogle ScholarPubMed
Brown, A. M., Akaike, N. & Lee, K. S. (1978). The calcium conductance of neurons. Ann. N. Y. Acad. Sci. 307, 330344.CrossRefGoogle ScholarPubMed
Brown, J. E., Cohen, L. B., DeWeer, P., Pinto, L. A., Ross, W. N. & Salzberg, B. M. (1975). Rapid changes of intracellular free calcium concentration: Detection by metallochromic indicator dyes in squid giant axon. Biophys. J. 15, 11551160.CrossRefGoogle ScholarPubMed
Burger, K. (1973). Organic Reagents in Metal Analysis. International Series of Monographs in Analytical Chemistry, vol. 54 Oxford: Pergamon Press.Google Scholar
Caldwell, P. C. (1960). The phosphorous metabolism of squid axons and its relationship to the active transport of sodium. J. Physiol. 152, 545560.CrossRefGoogle Scholar
Caldwell, P. C. & Keynes, R. D.The effect of ouabain on the efflux of sodium from a squid giant axon. J. Physiol. 148, 89P.Google Scholar
Caldwell, P. C. & Schirmer, H. (1965). The free energy available to the sodium pump of squid giant axons and changes in the sodium efflux on removal of the extracellular potassium. J. Physiol. 181, 2526P.Google Scholar
Caldwell-Violich, M. & Requena, J. (1977). Regulacion ionica en axones del calamar tropical Doryteuthis plei. Acta Cient. Venez.28 (1), 72.Google Scholar
Caldwell-Violich, M. & Requena, J. (1979). Magnesium content and net fluxes in squid giant axons. J. gen. Physiol. (in press).CrossRefGoogle Scholar
Caputo, C. & Bolanos, P. (1978). Effect of external sodium and calcium on calcium efflux in frog striated muscle. J. Membrane Biol. 41, 114.CrossRefGoogle ScholarPubMed
Carafoli, E. & Crompton, M. (1976). In Calcium in Biological Systems. Symp Soc. exp. Biol., no. xxx (ed. Duncan, C. J.).Google Scholar
deWeer, P. (1970). Effects of intracellular adenosine-5-diphosphate and ortophosphate on the sensitivity of sodium efflux from squid axon to external sodium and potassium. J. gen. Physiol. 56, 583620.CrossRefGoogle Scholar
Diecke, F. P. J., Perl, W., Stout, M. A. & Diecke, D. W. (1978). Radial diffusion of solutes in ‘internally dialyzed’ giant fiber. Biophys. J. 21, 207a.Google Scholar
DiPolo, R. (1973 a). Sodium dependent calcium influx in dialyzed barnacle muscle fibers. Biochim. biophys. Acta 298, 279283.CrossRefGoogle ScholarPubMed
DiPolo, R. (1973 b). Calcium efflux from internally dialyzed squid giant axons. J. gen. Phys ol. 62, 575589.CrossRefGoogle ScholarPubMed
DiPolo, R. (1977). Effect of ATP on the calcium efflux in dialyzed squid giant axons. J. gen. Physiol. 64, 503517.CrossRefGoogle Scholar
DiPolo, R. (1976). The influence of nucleolides on calcium fluxes Federation Proc. 35, 25792582.Google Scholar
DiPolo, R. (1977). Characterization of the ATP-dependent calcium efflux in dialyzed squid giant axons. J. gen. Physiol. 69, 795813.CrossRefGoogle ScholarPubMed
DiPolo, R. (1978). Ca pump driven by ATP in squid axons. Nature, Lond. 274, 390392.CrossRefGoogle ScholarPubMed
DiPolo, R. (1979). Calcium influx in internally dialyzed squid giant axons. J.gen. Physiol. 73, 91113.CrossRefGoogle ScholarPubMed
DiPolo, R. & Beaugé, L. (1979). Physiological role of ATP-driven calcium pump in squid axon. Nature, Lond. 278, 271273.CrossRefGoogle ScholarPubMed
DiPolo, R., Requena, J., Brinley, F. J. Jr, Mullins, L. J., Scarpa, A. & Tiffert, T. (1976). Ionized calcium concentrations in squid axons. J. gen. Physiol. 67, 433467.CrossRefGoogle ScholarPubMed
Doane, M. G. (1967). Fluorometric measurement of pyridine nucleoticle reduction in the giant axon of the squid. J. gen. Physiol. 50, 26032632.CrossRefGoogle Scholar
Drabikowski, W. (1974). In Calcium Binding Proteins. Elsevier.Google Scholar
Fluckiger, E. & Keynes, R. D. (1931). The calcium permeability of Loligo axons. J. Physiol. 128, 4142P.Google Scholar
Forbes, W. H. & Roughton, J. W. (1931). The equilibrium between oxygen and haemoglibin. J. Physiol. 71, 229256.CrossRefGoogle Scholar
Henkart, M. (1975). The endoplasmic reticulum of neurons as a calcium sequestering and releasing system: morphological evidence. Biophys. 15, 267a.Google Scholar
Henkart, M. P. 1979 Oral presentation at the Symposium on Identification and Function of lntracellular Calcium Stores in Neurons, 04 9, 1979. 63rd FASEB Meeting, Dallas, Texas.Google Scholar
Henkart, M. P., Reese, T. S. & Brinley, F. J. Jr (1978). Endoplasmic reticulum sequesters calcium in the squid giant axon. Science, 202 13001303.CrossRefGoogle ScholarPubMed
Hodgkin, A. L. (1958). Ionic movements and electrical activity in giant nerve fibers. Proc. R. Soc. Lond. B 148, 137.Google Scholar
Hodgkin, A. L. & Keynes, R. D. (1955) Active transport of cations in giant axons from sepia and loligo. J. Physiol. 128, 2860.CrossRefGoogle ScholarPubMed
Hodgkin, A. L. & Keynes, R. D. (1956). Experiments on the injection of substances into squid axons by means of a microsyringe. J. Physiol. 131, 592616.CrossRefGoogle ScholarPubMed
Hodgkin, A. L. & Keynes, R. D. (1957) Movements of labelled calcium in squid axons. J. Physiol. 138, 253281.CrossRefGoogle Scholar
Jobsis, F. F. & O'connor, M. J. (1966). Calcium release and reabsorption in the sartorious muscle of the toad. Biochem. biophys. Res. Comm. 25, 246252.CrossRefGoogle Scholar
Katz, B. & Miledi, R. (1969). Tetrodotoxin-resistant electric activity in presynaptic terminals. J. Physiol. 203, 459487.CrossRefGoogle ScholarPubMed
Keynes, R. D. & Lewis, P. R. (1956). The intracellular calcium contents of some invertebrate nerves. J. Physiol. 134, 399407.CrossRefGoogle ScholarPubMed
Koechlin, B. A. (1955). On the chemical composition of the axoplasm of squid giant nerve fibers with particular reference to ion pattern. J. biophys. biochem. Cytol. 1, 511529.CrossRefGoogle ScholarPubMed
Lardy, H. A., Witonsky, P. & Johnson, D. (1965).Antibiotics as tools for metabolic studies. IV. Comparative effectiveness of oligomycins A, B, C and rutamycin as inhibitors of phosphoryl transfer reactions in mitochondria. Biochemistry, N. Y. 4, 552.CrossRefGoogle Scholar
Lea, T. J. & Ashley, C. C. (1978). Increase in free Cal2+ in muscle after exposure to CO2. Nature, Lond. 275, 236238.CrossRefGoogle Scholar
Luttgau, H. C. & Niedergerke, R. (1958). The antagonism between Ca and Na ions in the frog's heart. J. Physiol. 143, 486505.CrossRefGoogle ScholarPubMed
Luxoro, M. & Yanez, E. (1968). Permeability of the giant axon of Dosidicus gigas to calcium ions. J. gen. Physiol. 51, 115s122s.CrossRefGoogle ScholarPubMed
Martonosi, A. N., Chyn, T. L. & Schibeci, A. (1978). The calcium transport of sarcoplasmic reticulum. Ann. N.Y. Acad. Sci. 307, 148157.CrossRefGoogle ScholarPubMed
Meves, H. & Vogel, W. (1973). Calcium inward currents in internally perfused giant axons. J. Physiol. 235, 225265.CrossRefGoogle ScholarPubMed
Michaylova, V. Y. & Ilkova, P. (1971). Photometric determination of microscopic amounts of calcium With Arsenazo III. Analytica chim. Acta 53, 194198.CrossRefGoogle Scholar
Mitchell, P. (1961). Coupling of phosphorylation to electron and hydrogen transfer by a chemiosmotic type of mechanism. Nature. 191, 144148.CrossRefGoogle ScholarPubMed
Mooke, J. W. & Cole, K. S. (1960). Resting and action potentials of the squid giant axon in vivo. J. gen. Physiol. 43, 961970.Google Scholar
Mullins, L. J. (1976). Steady-state calcium fluxes: membrane versus mitochondrial control of ionized calcium in axoplasm. Federation Proc. 35, 25832588.Google ScholarPubMed
Mullins, L. J. (1977). A mechanism for Na/Ca transport. J. gen. Physiol. 70, 681695.CrossRefGoogle ScholarPubMed
Mullins, L. J. (1979 a). The generation of electric currents in cardiac fibers by Na/Ca exchange. Am. J. Physiol. 236 (3), C103110.CrossRefGoogle ScholarPubMed
Mullins, L. J. (1979 b). Transport across axon membranes. In Membrane Transport in Biology, vol. 11. (ed. Tosteson, D. C.), pp. 161210. N.Y.: Springer-Verlag.Google Scholar
Mullins, L. J. & Brinley, F. J. Jr, (1967). Some factors influencing sodium extrusion by Internally Dialyzed Squid Axons. J. gen. Physiol. 50, 23332355.CrossRefGoogle ScholarPubMed
Mullins, L. J. & Brinley, F. J. Jr, (1975). Sensitivity of calcium efflux from squid axons to changes in membrane potential. J. gen. Physiol. 65, 135152.CrossRefGoogle ScholarPubMed
Mullins, L. J. & Requena, J. (1979). Ca measurement in the periphery of an axon. J. gen. Physiol. 74, 393413.CrossRefGoogle ScholarPubMed
Parker, J. C. (1978). Sodium and calcium movements in dog red blood cells. J. gen. Physiol. 71, 117.CrossRefGoogle ScholarPubMed
Portzehl, H., Caldwell, P. C. & Ruegg, J. G. (1964). The dependence of contraction and relaxation of muscle fibers from the crab maia squinado, on the internal concentration of free calcium ions. Biochim. biophys. Acta 79, 581591.Google ScholarPubMed
Reeves, J. P. & Sutko, J. L. (1979). Sodium-calcium ion exchange in cardiac membrane vesicles. Proc. Natn. Acad. Sci. U.S.A. 76, 590594.CrossRefGoogle ScholarPubMed
Requena, J. (1978 a). Effect of magnesium on Calcium efflux in dialyzed squid axon. Biochem. biophys. Acta 512, 452458.CrossRefGoogle ScholarPubMed
Requena, J. (1978 b). Calcium efflux from squid axons under constant sodium electrochemical gradient. J. gen. Physiol. 72, 443470.CrossRefGoogle ScholarPubMed
Requena, J.DiPolo, R., Brinley, F. J. Jr, & Mullins, L. J. (1979). The control of ionized calcium in squid axons. J. gen. Physiol. 70, 329353.CrossRefGoogle Scholar
Requena, J., Mullins, L. J. & Brinley, F. J. Jr, (1979). Calcium content and net fluxes in squid giant axons. J. gen. Physiol. 73, 327342.CrossRefGoogle ScholarPubMed
Reuter, H. (1973). Divalent ions as charge carriers in cxcitable membranes. Progr. Biophys. & molec. Biol. 26, 143.CrossRefGoogle ScholarPubMed
Reuter, H. & Seitz, N. (1968). The dependence of calcium efflux from cardiac muscle on temperature and external ion composition. J. Physiol 195, 451470.CrossRefGoogle ScholarPubMed
Robertson, J. D. (1949). Ionic regulation in some marine invertebrates. J. exp. Biol. 26, 182200.CrossRefGoogle ScholarPubMed
Rojas, E. & Hidalgo, C. (1968). Effect of temperature and metabolic inhibitors on 45Ca outflow from squid giant axons. Biochim. biophys. Acta. 163, 550556.CrossRefGoogle ScholarPubMed
Rojas, E. & Taylor, R. E. (1975). Simultaneous measurements of magnesium, calcium, and sodium influxes in perfused squid giant axons under membrane potential control. J. Physiol. 252, 127.CrossRefGoogle ScholarPubMed
Rojas, H., Blanco, R., DiPolo, R. & Caputo, C. (1978). The role of ATP on the rate of Ca extrusion from squid axons. Biophys. J. 21, 208a.Google Scholar
Scarpa, A. (1972). Spectrophotometric measurement of calcium by murixede. Meth Enzym. 24, 343357.CrossRefGoogle Scholar
Scarpa, A. (1979). Transport across mitochondrial membranes. In Membrane Transportin Biology, vol. II. (ed. Tosteson, D. C.), pp. 263355. N.Y.: Springer-Verlag.Google Scholar
Scarpa, A. & Carafoli, E. (1978). Calcium transport and cell function. Ann. N.Y. Acad. Sci. 307.Google Scholar
Schatzmann, H. J. & Eürgin, H. (1978). Calcium in human red blood cells. Ann. N.Y. Acad. Sci. 307, 125147.CrossRefGoogle ScholarPubMed
Shimomura, O., Johnson, F. H. & Saiga, Y. (1962). Extraction, purification and properties of Aequorin, a bioluminescent protein from the luminous hydromedusan, Aequorea. J. cell comp. Physiol. 59, 233239.CrossRefGoogle ScholarPubMed
Shultz, S. G. & Curran, P. F. (1970). Coupled transport of sodium and organic solutes. Physiol. Rev. 50, 637718.CrossRefGoogle Scholar
Sjodin, R. A. & Abercrombie, R. F. (1978). The influence of external cations and membrane potential on Ca-activated Na efflux in myxicola giant axons. J. gen. Physiol. 71, 453466.CrossRefGoogle ScholarPubMed
Somlyo, A. V., Shuman, H. & Somlyo, A. P. (1962). Elemental distribution in striated muscle and the effects of hypertonicity: Electron probe analysis of cryosections. J. Cell. Biol. 71, 828857.Google Scholar
Van, Breemen C. & DeWeer, P. (1970). Lanthanum inhibition of 45Ca efflux from squid giant axon. Nature, Lond. 226, 760761.Google Scholar
Wasserman, R. H. (1977). In Calcium Binding Proteins and Calcium Function. North Holland.Google Scholar
Wilbrandt, W. & Koller, H. (1948). Die Calciumwirkung am Froschherzen als Funktion des lonen gleichgewichts zwischen Zellmembran und Umgebumg. Helv. physiol. pharmacol. Acta 6, 208211.Google Scholar