Hydrogen ion currents in rat alveolar epithelial cells

DeCoursey, Thomas E.

doi:10.1016/s0006-3495(91)82158-0

Cited by 134 publications

(171 citation statements)

References 57 publications

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“…The first electrophysiological recording of voltage-dependent proton current in snail neurons were reported by Thomas and Meech [120]. Later studies, primarily done by DeCoursey group [121][122][123], found similar currents in other cell types [124]. However, controversy in the field on whether proton channels were in fact molecular entities had been present since 1989 after studies from Byerly and Suen [125].…”

Section: Discovery Of the Voltage-gated Proton Channel Hv1mentioning

confidence: 99%

Flagellar ion channels of sperm: similarities and differences between species

et al. 2015

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a b s t r a c tMotility and fertilization potential of mammalian sperm are regulated by ion homeostasis which in turn is under tight control of ion channels and transporters. Sperm intracellular pH, membrane voltage and calcium concentration ([Ca 2+ ] i ) are all important for sperm activity within the female reproductive tract. While all mammalian sperm are united in their goal to find and fertilize an egg, the molecular mechanisms they utilize for this purpose are diverse and differ between species especially on the level of ion channels. Recent direct recording from sperm cells of different species indicate the differences between rodent, non-human primate, ruminant, and human sperm on the basic levels of their ion channel regulation. In this review we summarize the current knowledge about ion channel diversity of the animal kingdom and concentrate our attention on flagellar ion channels of mammalian sperm.

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Section: Discovery Of the Voltage-gated Proton Channel Hv1mentioning

confidence: 99%

Flagellar ion channels of sperm: similarities and differences between species

et al. 2015

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“…Rat alveolar epithelial cells express a high density of voltage-gated proton channels (18,24,25), with properties different from those in neutrophils. No consistent change in either the H ϩ current amplitude or in gating kinetics was detected in six epithelial cells studied for up to 45 min after PMA treatment (data not shown).…”

Section: As Illustrated Inmentioning

confidence: 99%

Simultaneous activation of NADPH oxidase-related proton and electron currents in human neutrophils

DeCoursey

Cherny

Zhou

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

130

266

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Generation of reactive oxygen species by the NADPH oxidase complex is an important bactericidal weapon of phagocytes. Phorbol myristate acetate (PMA) is a potent agonist for this ''respiratory burst'' in human neutrophils. Although stoichiometric H ؉ efflux occurs during the respiratory burst, efforts to stimulate voltagegated H ؉ channels by PMA in whole-cell patch-clamped phagocytes have been unsuccessful. We have used a modification of the permeabilized-patch configuration that allows control of intracellular pH and preserves second-messenger pathways. Using this method, we show that PMA dramatically enhances and alters voltage-gated proton currents in human neutrophils. PMA produced four alterations in H ؉ current properties, each of which increases the H ؉ current at any given voltage: (i) a 40-mV negative shift in the H ؉ conductance-voltage (gH-V) relationship; (ii) faster activation [smaller activation time constant ( act)] during depolarizing pulses; (iii) slower deactivation [larger deactivation time constant ( tail)] on repolarization; and (iv) a larger maximum H ؉ conductance (gH,max). Inward current that directly reflects electron transport by NADPH oxidase was also activated by PMA stimulation. The identity of this electron current was confirmed by its sensitivity to diphenylene iodinium, an inhibitor of NADPH oxidase. Diphenylene iodinium also reversed the slowing of tail with a time course paralleling the inhibition of electron current. However, the amplitudes of H ؉ and electron currents activated by PMA were not correlated. A complex interaction between NADPH oxidase and voltage-gated proton channels is indicated. The data suggest that PMA stimulation modulates preexisting H ؉ channels rather than inducing a new H ؉ channel.respiratory burst ͉ hydrogen ion ͉ pH ͉ proton channel ͉ ion channels N ADPH oxidase is a major bactericidal weapon of neutrophils and other phagocytes (1). On stimulation, the enzyme complex assembles in the membrane and produces superoxide anion, the precursor to several bactericidal reactive oxygen species. NADPH oxidase is electrogenic (2), releasing a proton into the cytoplasm for each superoxide anion released into the phagocytic vacuole or extracellular medium. As a result, pH changes reflecting increased H ϩ permeability are seen during the respiratory burst in phagocytes (2, 3) after stimulation by the phorbol ester, phorbol 12-myristate 13-acetate (PMA). Voltagegated proton channels, discovered in snail neurons (4), were postulated to mediate the increased H ϩ permeability during the respiratory burst in human neutrophils (2, 5, 6). The importance of H ϩ efflux as a means of charge compensation is emphasized by the inhibition of PMA-stimulated superoxide anion production by Zn 2ϩ or Cd 2ϩ , which presumably act by inhibiting proton current (7,8). However, attempts to demonstrate effects of PMA on H ϩ currents in phagocytes studied in the whole-cell patchclamp configuration have heretofore been unsuccessful. It is therefore unclear whether the g H observed in phagoc...

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“…However, the flux of K ϩ ions, carried by valinomycin, can balance the charge generated by H ϩ movement, enabling extended observation of both inward and outward fluxes of H ϩ ions, driven by ⌬p. Electrophysiological studies have demonstrated the presence of voltage-activated H ϩ conductance in snail neurons (30), muscle cells (31), oocytes (32), epithelial cells (33), and phagocytes and phagocyte cell lines (34 -36). The currents are elicited from cells exposed to a large pH gradient (Ն1 pH unit) by the imposition of positive membrane potentials (Ն ϩ40 mV).…”

Section: Histidines In Gp91mentioning

confidence: 99%

Role of Histidines Identified by Mutagenesis in the NADPH Oxidase-associated H+ Channel

Henderson

1998

Journal of Biological Chemistry

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Hydrogen ion currents in rat alveolar epithelial cells

Cited by 134 publications

References 57 publications

Flagellar ion channels of sperm: similarities and differences between species

Flagellar ion channels of sperm: similarities and differences between species

Simultaneous activation of NADPH oxidase-related proton and electron currents in human neutrophils

Role of Histidines Identified by Mutagenesis in the NADPH Oxidase-associated H+ Channel

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