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Proton channels, plasma membrane potential, and respiratory burst in human neutrophils

Jaconi, Marisa
Published in European journal of haematology. 1993, vol. 51, no. 5, p. 309-312
Abstract When confronted with invading microorganisms, neutrophils undergo a number of nearly synchronous reactions including the generation of microbicidal reactive oxygen intermediates by the NADPH oxidase. These reactions are accompanied by a slow depolarization, from resting values of-60 mV to levels probably exceeding 0 mV. The depolarization is transient, indicating that a compensatory charge transport mechanism is activated. Activation of the oxidase system causes a massive burst of metabolic acid generation that would, if uncompensated, lower the intracellular pH of neutrophils by over 5 units, to lethal levels (pH = 2). Neutrophils must therefore possess particularly effective regulatory systems to avoid excessive cytosolic acidification. The recently described H+ conductance of neutrophils may counteract both the acidification and the depolarization. Activation of the H+ conductance occurs at depolarizing voltages and is promoted by cytosolic acidification, a combination that takes place during the respiratory burst. The NADPH oxidase of neutrophils is thus associated to an unusual, particularly efficient mechanism of H+ export and charge compensation. The sequential activation of these two systems causes neutrophils to depolarize through the activation of an electron transport chain, and to repolarize through the activation of a H+ conductance.
Keywords Cell Membrane/ physiologyHumansHydrogen-Ion ConcentrationMembrane PotentialsNeutrophils/ physiologyProton Pumps/ physiologyRespiratory Burst
PMID: 8282093
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DEMAUREX, Nicolas et al. Proton channels, plasma membrane potential, and respiratory burst in human neutrophils. In: European journal of haematology, 1993, vol. 51, n° 5, p. 309-312. https://archive-ouverte.unige.ch/unige:9308

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