Cellular and Molecular Neurobiology

, Volume 14, Issue 6, pp 841–857 | Cite as

Differential effects of heavy metal ions on Ca2+-dependent K+ channels

  • H. P. M. Vijverberg
  • T. Leinders-Zufall
  • R. G. D. M. van Kleef


1. The ability of various divalent metal ions to substitute for Ca2+ in activating distinct types of Ca2+-dependent K+ [K+(Ca2+] channels has been investigated in excised, inside-out membrane patches of human erthrocytes and of clonal N1E-115 mouse neuroblastoma cells using the patch clamp technique. The effects of the various metal ions have been compared and related to the effects of Ca2+.

2. At concentrations between 1 and 100 µM Pb2+, Cd2+ and Co2+ activate intermediate conductance K+(Ca2+) channels in erythrocytes and large conductance K+(Ca2+) channels in neuroblastoma cells. Pb2+ and Co2+, but not Cd2+, activate small conductance K+(Ca2+) channels in neuroblastoma cells. Mg2+ and Fe2+ do not activate any of the K+(Ca2+) channels.

3. Rank orders of the potencies for K+(Ca2+) activation are Pb2+, Cd2+>Ca2+, Co2+>>Mg2+, Fe2+ for the intermediate erythrocyte K+(Ca2+) channel, and Pb2+, Cd2+>Ca2+>Co2+>>Mg2+, Fe2+ for the small, and Pb2+>Ca2+>Co2+>>Cd2+, Mg2+, Fe2+ for the large K+(Ca2+) channel in neuroblastoma cells.

4. At high concentrations Pb2+, Cd2+, and Co2+ block K+(Ca2+) channels in erythrocytes by reducing the opening frequency of the channels and by reducing the single channel amplitude. The potency orders of the two blocking effects are Pb2+>Cd2+, Co2+>>Ca2+, and Cd2+>Pb2+, Co2+>>Ca2+, respectively, and are distinct from the potency orders for activation.

5. It is concluded that the different subtypes of K+(Ca2+) channels contain distinct regulatory sites involved in metal ion binding and channel opening. The K+(Ca2+) channel in erythrocytes appears to contain additional metal ion interaction sites involved in channel block.

Key words

lead cadmium cobalt single channel patch clamp calcium-activated potassium channel human erythrocyte N1E-115 mouse neuroblastoma cell 


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  1. Amano, T., Richelson, E., and Nirenberg, P. G. (1972). Neurotransmitter synthesis by neuroblastoma clones.Proc. Natl. Acad. Sci. USA 69:258–263.Google Scholar
  2. Audesirk, G., and Audesirk, T. (1991). Effects of inorganic lead on voltage-sensitive calcium channels in N1E-115 neuroblastoma cells.Neurotoxicology 12:519–528.Google Scholar
  3. Bendat, J. S., and Piersol, A. G. (1971).Random Data: Analysis and Measurement Procedures, Wiley-Interscience, New York.Google Scholar
  4. Capiod, T., and Ogden, D. C. (1989). The properties of calcium-activated potassium channels in guinea-pig isolated hepatocytes.J. Physiol. (London) 409:285–295.Google Scholar
  5. Gola, M., Ducreux, C., and Chagneux, H. (1990). Ca2+-activated K+ current involvement in neuronal function revealed by in situ single channel analysis inHelix neurones.J. Physiol. (London) 420:73–109.Google Scholar
  6. Gorman, A. L. F., and Hermann, A. (1979). Internal effects of divalent cations on potassium permeability in molluscan neurones.J. Physiol. (London) 296:393–410.Google Scholar
  7. Grygorczyk, R., and Schwarz, W. (1983). Properties of the Ca2+-activated K+ conductance of human red cells as revealed by the patch-clamp technique.Cell Calcium 4:499–510.Google Scholar
  8. Grygorczyk, R., Schwarz, W., and Passow, H. (1984). Ca2+-activated K+ channels in human red cells.Biophys. J. 45:693–698.Google Scholar
  9. Habermann, E., Crowell, K., and Janicki, P. (1983). Lead and other metals can substitute for Ca2+ in calmodulin.Arch. Toxicol. 54:61–70.Google Scholar
  10. Hamill, O. P. (1981). Potassium channel currents in human red blood cells.J. Physiol. (London) 319:97P-98P.Google Scholar
  11. Hamill, O. P., Marty, A., Neher, E., Sakmann, B., and Sigworth, F. J. (1981). Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches.Pflügers Arch. 391:85–100.Google Scholar
  12. Kolb, H. A. (1990). Potassium channels in excitable and non-excitable cells.Rev. Physiol. Biochem. Pharmacol. 115:51–91.Google Scholar
  13. Krigman, M. R., Bouldin, T. W., and Mushak, P. (1980). InExperimental and Clinical Neurotoxicology (P. S. Spencer and H. H. Schaumburg, Eds.), Williams & Wilkins, Baltimore/London, pp. 490–507.Google Scholar
  14. Lancaster, B., Nicoll, R. A., and Perkel, D. J. (1991). Calcium activates two types of potassium channels in rat hippocampal neurones in culture.J. Neurosci. 11:23–30.Google Scholar
  15. Leinders, T., and Vijverberg, H. P. M. (1992). Ca2+ dependence of small Ca2+-activated K+ channels in cultured N1E-115 cells.Pflügers Arch. 422:223–232.Google Scholar
  16. Leinders, T., van Kleef, R. G. D. M., and Vijverberg, H. P. M. (1992a). Divalent cations activate small- (SK) and large-conductance (BK) channels in mouse neuroblastoma cells: selective activation of SK channels by cadmium.Pflügers Arch. 422:217–222.Google Scholar
  17. Leinders, T., van Kleef, R. G. D. M., and Vijverberg, H. P. M. (1992b). Single Ca2+-activated K+ channels in human erythrocytes: Ca2+ dependence of opening frequency but not of open life times.Biochim. Biophys. Acta 1112:67–74.Google Scholar
  18. Leinders, T., van Kleef, R. G. D. M., and Vijverberg, H. P. M. (1992c). Distinct metal ion binding sites on Ca2+-activated K+ channels in inside-out patches of human erythrocytes.Biochim. Biophys. Acta 1112:75–82.Google Scholar
  19. Long, G. J., Rosen, J. F., and Schanne, F. A. X. (1994). Lead activation of protein kinase C from rat brain.J. Biol. Chem. 269:834–837.Google Scholar
  20. Markovac, J., and Goldstein, G. W. (1988). Picomolar concentrations of lead stimulate brain protein kinase C.Nature 334:71–73.Google Scholar
  21. Müller, T. H., Swandulla, D., and Lux, H. D. (1989). Activation of three types of membrane currents by various divalent cations in identified molluscan pacemaker neurons.J. Gen. Physiol. 94:997–1014.Google Scholar
  22. Oberhauser, A., Alvarez, O., and Latorre, R. (1988). Activation by divalent cations of a Ca2+-activated K+ channel from skeletal muscle membrane.J. Gen. Physiol. 92:67–86.Google Scholar
  23. Oortgiesen, M., van Kleef, R. G. D. M., Bajnath, R. B., and Vijverberg, H. P. M. (1989). Nanomolar concentration of lead selectively block neuronal nicotinic responses in mouse neuroblastoma cells.Toxicol. Appl. Pharmacol. 103:165–174.Google Scholar
  24. Oortgiesen, M., van Kleef, R. G. D. M., and Vijverberg, H. P. M. (1990). Novel type of ion channel activated by Pb2+, Cd2+, and Al3+ in cultured mouse neuroblastoma cells.J. Membr. Biol. 113:261–268.Google Scholar
  25. Oortgiesen, M., Leinders, T., van Kleef, R. G. D. M., and Vijverberg, H. P. M. (1993). Differential neurotoxicological effects of lead on voltage-dependent and receptor-operated ion channels.Neurotoxicology 14:87–96.Google Scholar
  26. Pennefather, P., Lancaster, B., Adams, P. R., and Nicoll, R. A. (1985). Two distinct Ca-dependent K currents in bullfrog sympathetic ganglion cells.Proc. Natl. Acad. Sci. USA 82:3040–3044.Google Scholar
  27. Perrin, D. G. (1979).Stability Constants of Metal-Ion Complexes. Part B: Organic Ligands, IUPAC Chemical Data Series No. 22, Pergamon Press, Oxford.Google Scholar
  28. Pounds, J. G. (1984). Effect of lead intoxication on calcium homeostasis and calcium-mediated cell function: A review.Neurotoxicology 5:295–332.Google Scholar
  29. Reinhart, P. H., Chung, S., and Levitan, I. B. (1989). A family of calcium-dependent potassium channels from rat brain.Neuron 2:1031–1041.Google Scholar
  30. Richardt, G., Federolg, G., and Habermann, E. (1986). Affinity of heavy metal ions to intracellular Ca2+-binding proteins.Biochem. Pharmacol. 35:1331–1336.Google Scholar
  31. Romey, G., and Lazdunski, M. (1984). The coexistence in rat muscle cells of two distinct classes of Ca2+-dependent K+ channels with different pharmacological properties and different physiological functions.Biochem. Biophys. Res. Commun. 118:669–674.Google Scholar
  32. Rudy, B. (1988). Diversity and ubiquity of K channels.Neuroscience 25:729–751.Google Scholar
  33. Schanne, F. A. X., Moskal, J. R., and Gupta, R. K. (1989). Effect of lead on intracellular free calcium ion concentration in a presynaptic neuronal model:19F-NMR study of NG108-15 cells.Brain Res. 503:308–311.Google Scholar
  34. Shields, M., Grygorczyk, K., Fuhrmann, G. F., Schwarz, W., and Passow, H. (1985). Lead-induced activation and inhibition of potassium-selective channels in the human red blood cell.Biochim. Biophys. Acta 815:223–232.Google Scholar
  35. Sillen, L. G., and Martell, A. E. (1971).Stability Constants of Metal-Ion Complexes, Supplement No. 1, Special Publication No. 25, The Chemical Society, London.Google Scholar
  36. Simons, T. J. B. (1985). Influence of lead ions on cation permeability in human red cell ghosts.J. Membr. Biol. 84:61–71.Google Scholar
  37. Simons, T. J. B. (1993). Lead-calcium interactions in cellular lead toxicity.Neurotoxicology 14:77–86.Google Scholar
  38. Van Heeswijk, M. P. E., Geertsen, J. A. M., and van Os, C. H. (1984). Kinetic properties of the ATP-dependent Ca2+ pump and the Na+/Ca2+ exchange system in basolateral membranes from rat kidney cortex.J. Membr. Biol. 79:19–31.Google Scholar
  39. Verheugen, J. A. H., van Kleef, R. G. D. M., Oortgiesen, M., and Vijverberg, H. P. M. (1994). Characterization of Ca2+-activated K+ channels in excised patches of human T lymphocytes.Pflügers Arch. 426:465–471.Google Scholar

Copyright information

© Plenum Publishing Corporation 1994

Authors and Affiliations

  • H. P. M. Vijverberg
    • 1
  • T. Leinders-Zufall
    • 2
  • R. G. D. M. van Kleef
    • 1
  1. 1.Research Institute of ToxicologyUtrecht UniversityUtrechtThe Netherlands
  2. 2.Section Neurobiology (FMB 236)Yale University School of MedicineNew Haven

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