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Title: Characterisation of electron currents generated by the human neutrophil NADPH oxidase

Abstract

Electron transport by the human neutrophil NADPH oxidase is an important microbicidal weapon for phagocytes. The electron current (I{sub e}) generated by the neutrophil NADPH oxidase is poorly characterised due to the lack of appropriate electrophysiological data. In this study, I fully characterise the neutrophil generated I{sub e} when the NADPH oxidase is activated by NADPH and GTP{gamma}S. The neutrophil I{sub e} was markedly voltage-dependent in the entire voltage range in comparison to those electron currents measured after chloride was removed from the external bath solution. The difference in I{sub e} measured in chloride free conditions was not due to a change in the activation kinetics of voltage-gated proton channels. The I{sub e} depolarises the neutrophil plasma membrane at a rate of 2.3 V s{sup -1} and this depolarisation was opposed when voltage-gated proton channels are activated. 3 mM ZnCl{sub 2} depolarised the membrane potential to +97.8 {+-} 2.5 mV (n = 4), and this depolarisation was abolished after NADPH oxidase inhibition.

Authors:
 [1]
  1. Leukocyte and Ion Channel Research Laboratory, School of Health and Biosciences, University of East London, Stratford Campus, London E15 4LZ (United Kingdom), E-mail: j.ahluwalia@uel.ac.uk
Publication Date:
OSTI Identifier:
21043702
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 368; Journal Issue: 3; Other Information: DOI: 10.1016/j.bbrc.2008.01.161; PII: S0006-291X(08)00190-3; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; CELL MEMBRANES; ELECTRIC POTENTIAL; ELECTRONS; NEUTROPHILS; OXIDASES; PHAGOCYTES; PROTONS; ZINC CHLORIDES

Citation Formats

Ahluwalia, Jatinder. Characterisation of electron currents generated by the human neutrophil NADPH oxidase. United States: N. p., 2008. Web. doi:10.1016/j.bbrc.2008.01.161.
Ahluwalia, Jatinder. Characterisation of electron currents generated by the human neutrophil NADPH oxidase. United States. doi:10.1016/j.bbrc.2008.01.161.
Ahluwalia, Jatinder. 2008. "Characterisation of electron currents generated by the human neutrophil NADPH oxidase". United States. doi:10.1016/j.bbrc.2008.01.161.
@article{osti_21043702,
title = {Characterisation of electron currents generated by the human neutrophil NADPH oxidase},
author = {Ahluwalia, Jatinder},
abstractNote = {Electron transport by the human neutrophil NADPH oxidase is an important microbicidal weapon for phagocytes. The electron current (I{sub e}) generated by the neutrophil NADPH oxidase is poorly characterised due to the lack of appropriate electrophysiological data. In this study, I fully characterise the neutrophil generated I{sub e} when the NADPH oxidase is activated by NADPH and GTP{gamma}S. The neutrophil I{sub e} was markedly voltage-dependent in the entire voltage range in comparison to those electron currents measured after chloride was removed from the external bath solution. The difference in I{sub e} measured in chloride free conditions was not due to a change in the activation kinetics of voltage-gated proton channels. The I{sub e} depolarises the neutrophil plasma membrane at a rate of 2.3 V s{sup -1} and this depolarisation was opposed when voltage-gated proton channels are activated. 3 mM ZnCl{sub 2} depolarised the membrane potential to +97.8 {+-} 2.5 mV (n = 4), and this depolarisation was abolished after NADPH oxidase inhibition.},
doi = {10.1016/j.bbrc.2008.01.161},
journal = {Biochemical and Biophysical Research Communications},
number = 3,
volume = 368,
place = {United States},
year = 2008,
month = 4
}
  • Chloride channels activated by swell have important functions in many physiological processes. The phagocyte NADPH oxidase is essential for host defence and it generates superoxide by transferring electrons from the donor NADPH to the acceptor O{sub 2}. This electron current, induces a depolarisation of the plasma membrane. In this study, I report that chloride channels activated by swell can counteract the depolarisation induced by the NADPH oxidase. When a chloride conductance was activated by swelling, its inhibition by either 50 {mu}M NPPB or removing external chloride, depolarised the plasma membrane potential to +26 mV {+-} 3.1 (n = 4) andmore » +40 {+-} 1 mV (n = 4), respectively. These channels were partially inhibited by the NADPH oxidase inhibitor AEBSF (1 mM) and potently inhibited by ZnCl{sub 2} (3 mM). These currents were not activated by a phosphorylation step and elevations in intracellular calcium did not appear to activate chloride currents similar to those activated by swell.« less
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