Skip to main content
PMC home page
Biophysical Journal logoLink to Biophysical Journal
. 1984 Dec;46(6):821–825. doi: 10.1016/S0006-3495(84)84080-1

Calcium- and voltage-activated potassium channels in human macrophages.

E K Gallin
PMCID: PMC1435102  PMID: 6097318

Abstract

Single calcium-activated potassium channel currents were recorded in intact and excised membrane patches from cultured human macrophages. Channel conductance was 240 pS in symmetrical 145 mM K+ and 130 pS in 5 mM external K+. Lower conductance current fluctuations (40% of the larger channels) with the same reversal potential as the higher conductance channels were noted in some patches. Ion substitution experiments indicated that the channel is permeable to potassium and relatively impermeable to sodium. The frequency of channel opening increased with depolarization and intracellular calcium concentration. At 10(-7) M (Ca++)i, channel activity was evident only at potentials of +40 mV or more depolarized, while at 10(-5) M, channels were open at all voltages tested (-40 to +60 mV). In intact patches, channels were seen at depolarized patch potentials of +50 mV or greater, indicating that the ionized calcium concentration in the macrophage is probably less than 10(-7) M.

Full text

PDF
821

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Barrett J. N., Magleby K. L., Pallotta B. S. Properties of single calcium-activated potassium channels in cultured rat muscle. J Physiol. 1982 Oct;331:211–230. doi: 10.1113/jphysiol.1982.sp014370. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Gallin E. K. Electrophysiological properties of macrophages. Fed Proc. 1984 Jun;43(9):2385–2389. [PubMed] [Google Scholar]
  3. Gallin E. K. Voltage clamp studies in macrophages from mouse spleen cultures. Science. 1981 Oct 23;214(4519):458–460. doi: 10.1126/science.7291986. [DOI] [PubMed] [Google Scholar]
  4. Gallin E. K., Wiederhold M. L., Lipsky P. E., Rosenthal A. S. Spontaneous and induced membrane hyperpolarizations in macrophages. J Cell Physiol. 1975 Dec;86 (Suppl 2)(3 Pt 2):653–661. doi: 10.1002/jcp.1040860510. [DOI] [PubMed] [Google Scholar]
  5. Kolb H. A., Schwarze W. Properties of a cation channel of large unit conductance in lymphocytes, macrophages and cultured muscle cells. Biophys J. 1984 Jan;45(1):136–138. doi: 10.1016/S0006-3495(84)84139-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Marty A. Ca-dependent K channels with large unitary conductance in chromaffin cell membranes. Nature. 1981 Jun 11;291(5815):497–500. doi: 10.1038/291497a0. [DOI] [PubMed] [Google Scholar]
  7. McCann F. V., Cole J. J., Guyre P. M., Russell J. A. Action potentials in macrophages derived from human monocytes. Science. 1983 Feb 25;219(4587):991–993. doi: 10.1126/science.6823563. [DOI] [PubMed] [Google Scholar]
  8. Persechini P. M., Araujo E. G., Oliveira-Castro G. M. Electrophysiology of phagocytic membranes: induction of slow membrane hyperpolarizations in macrophages and macrophage polykaryons by intracellular calcium injection. J Membr Biol. 1981;61(2):81–90. doi: 10.1007/BF02007634. [DOI] [PubMed] [Google Scholar]
  9. Petersen O. H., Maruyama Y. Calcium-activated potassium channels and their role in secretion. Nature. 1984 Feb 23;307(5953):693–696. doi: 10.1038/307693a0. [DOI] [PubMed] [Google Scholar]
  10. Rosenstreich D. L., Farrar J. J., Dougherty S. Absolute macrophage dependency of T lymphocyte activation by mitogens. J Immunol. 1976 Jan;116(1):131–139. [PubMed] [Google Scholar]
  11. Singer J. J., Walsh J. V. Large conductance ca-activated k channels in smooth muscle cell membrane: reduction in unitary currents due to internal na ions. Biophys J. 1984 Jan;45(1):68–70. doi: 10.1016/s0006-3495(84)84112-0. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Biophysical Journal are provided here courtesy of The Biophysical Society

RESOURCES