In a wide variety of cells, various intracellular agents, such as Ca2+ (refs 1,2), ATP3,4 and cyclic nucleotides5,6, regulate ionic conductances of the membrane. In cardiac cells, the intracellular Na+ concentration ([Na+]i) frequently increases when a disturbance occurs in the electrogenic Na–K pump activity or the Na–Ca exchange mechanism. We have investigated a possible role of [Na+]i in controlling ion channels by using a patch-clamp method7, and have found a K+ channel that is gated by [Na+]i >20mM, but not by the intracellular Ca2+ concentration (∼10−4M). We report here that the channel has a unitary conductance of 207 ± 19 pS(n = 16) with K+ concentrations of 150 mM outside and 49 mM inside, and shows no detectable voltage-dependent kinetics. The Na+-activated K+ channel represents a novel class of ionic channel.
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Meech, R. W. A. Rev. Biophys. Bioengng 7, 1–18 (1978).
Colquhoun, D., Neher, E., Reuter, H. & Stevens, C. F. Nature 294, 752–754 (1981).
Kostyuk, P. G., Krishtal, O. A. & Pidoplichko, V. I. J. Physiol., Lond. 310, 403–421 (1981).
Noma, A. Nature 305, 147–148 (1983).
Reuter, H. & Scholz, H. J. Physiol., Lond. 264, 49–62 (1977).
Klein, M., Camardo, J. & Kandel, E. R. Proc. natn. Acad. Sci. U.S.A. 79, 5713–5717 (1982).
Hamill, O. P., Marty, A., Neher, E., Sakmann, B. & Sigworth, F. J. Pflügers Arch. ges. Physiol. 391, 85–100 (1981).
Isenberg, G. & Klöckner, U. Pflügers Arch. ges. Physiol. 395, 6–18 (1982).
Taniguchi, J., Kokubun, S., Noma, A. & Irisawa, H. Jap. J. Physiol. 31, 547–558 (1981).
Kameyama, M., Kiyosue, T. & Soejima, M. Jap. J. Physiol. 33, 1039–1056 (1983).
Sakmann, B. & Trube, G. J. Physiol., Lond. 347, 641–657 (1984).
Sakmann, B. & Trube, G. J. Physiol., Lond. 347, 659–683 (1984).
Latorre, R. & Miller, C. J. Membrane Biol. 71, 11–30 (1983).
Hagiwara, S. & Yoshii, M. J. Physiol., Lond. 292, 251–265 (1979).
Lee, C. O. & Fozzard, H. J. gen. Physiol. 65, 695–708 (1975).
Ellis, D. J. Physiol., Lond. 273, 211–240 (1977).
Vleugels, A., Vereeke, J. & Carmeliet, E. Circulation Res. 47, 501–508 (1980).
Mullins, L. J. Ion Transport in Heart (Raven, New York, 1981).
Glitsch, H. G. Am. J. Physiol. 236, H189–199 (1979).
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Kameyama, M., Kakei, M., Sato, R. et al. Intracellular Na+ activates a K+ channel in mammalian cardiac cells. Nature 309, 354–356 (1984). https://doi.org/10.1038/309354a0
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