HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Tare, M. Articles by Bolton, T. B. Search for Related Content PubMed PubMed Citation Articles by Tare, M. Articles by Bolton, T. B.

Inwardly rectifying whole cell potassium current in human blood eosinophils

M. Tare, S. A. Prestwich, D. V. Gordienko, S. Parveen, J. E. Carver, C. Robinson and T. B. Bolton

1. Membrane currents were studied in single human blood eosinophils using the whole cell voltage clamp technique. The whole cell current-voltage relationship exhibited rectification about the membrane potential which followed the potassium equilibrium potential when [K⁺]_o was raised. Elevation of [K⁺]_o considerably potentiated inward current amplitude, and in some cells channel activity was discernible in the whole cell membrane current recordings. The single channel conductance was 24 ± 1 pS ([K⁺]_o, 100 mM; [K⁺]_i, 140 mM), and eosinophils were found to have as few as three, and on average twenty, inward rectifier channels each.

2. The inward current was inhibited in a voltage-dependent manner by extracellular cations in order of potency Ba²⁺ > Cs⁺ > Na⁺. Intracellular acidification inhibited while alkalization augmented the inward current. Mg²⁺ contributed to rectification as dialysis with nominally Mg²⁺-free pipette solution was associated with an increase in the outward current during membrane polarization.

3. By reverse transcription-polymerase chain reaction (RT-PCR) using suitable primers on human eosinophil mRNA, an inward rectifier channel, Kir2.1, was identified, which is known from expression studies to have very similar properties to those found in this study.

4. Superoxide anion production or its stimulation by phorbol 12-myristate 13-acetate (PMA) was not significantly affected by depolarization with 140 mM [K⁺]_o, or by 1 mM BaCl₂.

5. It is concluded that the single channel currents and the whole cell current rectification observed in human blood eosinophils resulted from the presence of an inwardly rectifying potassium channel, probably Kir2.1.

This article has been cited by other articles:

				J. K. Femling, V. V. Cherny, D. Morgan, B. Rada, A. P. Davis, G. Czirjak, P. Enyedi, S. K. England, J. G. Moreland, E. Ligeti, et al. The Antibacterial Activity of Human Neutrophils and Eosinophils Requires Proton Channels but Not BK Channels J. Gen. Physiol., May 30, 2006; 127(6): 659 - 672. [Abstract] [Full Text] [PDF]

				J. V. Wu, M. E. Krouse, A. Rustagi, N. S. Joo, and J. J. Wine An Inwardly Rectifying Potassium Channel in Apical Membrane of Calu-3 Cells J. Biol. Chem., November 5, 2004; 279(45): 46558 - 46565. [Abstract] [Full Text] [PDF]

				T. E. DeCoursey During the Respiratory Burst, Do Phagocytes Need Proton Channels or Potassium Channels, or Both? Sci. Signal., May 18, 2004; 2004(233): pe21 - pe21. [Abstract] [Full Text] [PDF]

				J. L. Bankers-Fulbright, G. J. Gleich, G. M. Kephart, H. Kita, and S. M. O'Grady Regulation of eosinophil membrane depolarization during NADPH oxidase activation J. Cell Sci., August 1, 2003; 116(15): 3221 - 3226. [Abstract] [Full Text] [PDF]

				P. Bradding, Y. Okayama, N. Kambe, and H. Saito Ion channel gene expression in human lung, skin, and cord blood-derived mast cells J. Leukoc. Biol., May 1, 2003; 73(5): 614 - 620. [Abstract] [Full Text] [PDF]

				T. E. Decoursey Voltage-Gated Proton Channels and Other Proton Transfer Pathways Physiol Rev, April 1, 2003; 83(2): 475 - 579. [Abstract] [Full Text] [PDF]

				A. Schwingshackl, R. Moqbel, and M. Duszyk Nitric oxide activates ATP-dependent K+ channels in human eosinophils J. Leukoc. Biol., May 1, 2002; 71(5): 807 - 812. [Abstract] [Full Text] [PDF]

				H. Oonuma, K. Iwasawa, H. Iida, T. Nagata, H. Imuta, Y. Morita, K. Yamamoto, R. Nagai, M. Omata, and T. Nakajima Inward Rectifier K+ Current in Human Bronchial Smooth Muscle Cells . Inhibition with Antisense Oligonucleotides Targeted to Kir2.1 mRNA Am. J. Respir. Cell Mol. Biol., March 1, 2002; 26(3): 371 - 379. [Abstract] [Full Text] [PDF]

				J. Ji, A. M. F. Salapatek, and N. E. Diamant Inwardly rectifying K+ channels in esophageal smooth muscle Am J Physiol Gastrointest Liver Physiol, November 1, 2000; 279(5): G951 - G960. [Abstract] [Full Text] [PDF]

				B. Banfi, J. Schrenzel, O. Nusse, D. P. Lew, E. Ligeti, K.-H. Krause, and N. Demaurex A Novel H+ Conductance in Eosinophils: Unique Characteristics and Absence in Chronic Granulomatous Disease J. Exp. Med., July 19, 1999; 190(2): 183 - 194. [Abstract] [Full Text] [PDF]

				R. A. Chavez, A. T. Gray, B. B. Zhao, C. H. Kindler, M. J. Mazurek, Y. Mehta, J. R. Forsayeth, and C. S. Yost TWIK-2, a New Weak Inward Rectifying Member of the Tandem Pore Domain Potassium Channel Family J. Biol. Chem., March 19, 1999; 274(12): 7887 - 7892. [Abstract] [Full Text] [PDF]