scholarly journals Respiratory burst enzyme in human neutrophils. Evidence for multiple mechanisms of activation.

1981 ◽  
Vol 67 (3) ◽  
pp. 710-716 ◽  
Author(s):  
L C McPhail ◽  
P M Henson ◽  
R B Johnston
Keyword(s):  
Respiratory Burst ◽  
Human Neutrophils ◽  
Respiratory Burst Enzyme

The Flavonols Quercetin, Myricetin, Kaempferol, and Galangin Inhibit the Net Oxygen Consumption by Immune Complex- Stimulated Human and Rabbit Neutrophils

2014 ◽  
Vol 69 (7-8) ◽  
pp. 346-356 ◽  
Author(s):  
Andréa S. G. Figueiredo-Rinhel ◽  
Everton O. L. Santos ◽  
Luciana M. Kabeya ◽  
Ana Elisa C. S. Azzolini ◽  
Livia M. C. Simões-Ambrosio ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Immune Complex ◽  
Respiratory Burst ◽  
Human Neutrophil ◽  
Inflammatory Diseases ◽  
Cell Types ◽  
Oxygen Electrode ◽  
Experimental Models ◽  
Human Neutrophils ◽  
Experimental Conditions

Stimulated human neutrophils exhibit increased net oxygen consumption (NOC) due to the conversion of O2 into the superoxide anion by the NADPH oxidase enzymatic complex during the respiratory burst. In several inflammatory diseases, overproduction of these oxidants causes tissue damage. The present study aims to: (a) optimize the experimental conditions used to measure the NOC in serum-opsonized zymosan (OZ)-and insoluble immune complex (i-IC)-stimulated human and rabbit neutrophils; and (b) compare the effect of four flavonols (quercetin, myricetin, kaempferol, and galangin) on this activity. We used a Clark-type oxygen electrode to measure the NOC of stimulated neutrophils. Eliciting the neutrophil respiratory burst with OZ and i-IC yielded similar maximum O2 uptake levels within the same species, but the human neutrophil NOC was almost four times higher than the rabbit neutrophil NOC. The optimal experimental conditions established for both cell types were 4·106 neutrophils mL-1, 2 mg mL-1 OZ, and 240 µg mL-1 i-IC. Upon stimulation with OZ or i-IC, the tested flavonols reduced the human and rabbit neutrophil NOC in the same order of potency - quercetin and galangin were the most and the least potent, respectively. These compounds were around four times more effective in inhibiting the rabbit as compared to the human neutrophil NOC, respectively. The four flavonols were not toxic to human or rabbit neutrophils. The experimental conditions used are suitable for both the determination of human and rabbit neutrophil NOC and for the assessment of the modulatory effects of natural compounds on these activities. The relationship between the level of NOC and the inhibitory potency of the flavonols suggests that rabbit neutrophils can be useful experimental models to predict the effect of drugs on immune complexstimulated human neutrophils.

scholarly journals Standardization of the antibody-dependent respiratory burst assay with human neutrophils and Plasmodium falciparum malaria

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
David Llewellyn ◽  
Kazutoyo Miura ◽  
Michael P. Fay ◽  
Andrew R. Williams ◽  
Linda M. Murungi ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Falciparum Malaria ◽  
Respiratory Burst ◽  
Plasmodium Falciparum Malaria ◽  
Human Neutrophils

scholarly journals The Antibacterial Activity of Human Neutrophils and Eosinophils Requires Proton Channels but Not BK Channels

2006 ◽  
Vol 127 (6) ◽  
pp. 659-672 ◽  
Author(s):  
Jon K. Femling ◽  
Vladimir V. Cherny ◽  
Deri Morgan ◽  
Balázs Rada ◽  
A. Paige Davis ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Respiratory Burst ◽  
Essential Role ◽  
Outward Current ◽  
Bk Channels ◽  
Bk Channel ◽  
Human Neutrophils ◽  
H2o2 Production ◽  
Proton Channels ◽  
Voltage Gated

Electrophysiological events are of central importance during the phagocyte respiratory burst, because NADPH oxidase is electrogenic and voltage sensitive. We investigated the recent suggestion that large-conductance, calcium-activated K+ (BK) channels, rather than proton channels, play an essential role in innate immunity (Ahluwalia, J., A. Tinker, L.H. Clapp, M.R. Duchen, A.Y. Abramov, S. Page, M. Nobles, and A.W. Segal. 2004. Nature. 427:853–858). In PMA-stimulated human neutrophils or eosinophils, we did not detect BK currents, and neither of the BK channel inhibitors iberiotoxin or paxilline nor DPI inhibited any component of outward current. BK inhibitors did not inhibit the killing of bacteria, nor did they affect NADPH oxidase-dependent degradation of bacterial phospholipids by extracellular gIIA-PLA2 or the production of superoxide anion (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{O}_{2^{.}}^{{-}}\) \end{document}). Moreover, an antibody against the BK channel did not detect immunoreactive protein in human neutrophils. A required role for voltage-gated proton channels is demonstrated by Zn2+ inhibition of NADPH oxidase activity assessed by H2O2 production, thus validating previous studies showing that Zn2+ inhibited \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{O}_{2^{.}}^{{-}}\) \end{document} production when assessed by cytochrome c reduction. In conclusion, BK channels were not detected in human neutrophils or eosinophils, and BK inhibitors did not impair antimicrobial activity. In contrast, we present additional evidence that voltage-gated proton channels serve the essential role of charge compensation during the respiratory burst.

[Ca2+ ]i Changes and Respiratory Burst in Human Neutrophils and Monocytes Induced by NAP-1/Interleukin-8, NAP-2, and gro /MGSA

1991 ◽  
Vol 50 (3) ◽  
pp. 279-286 ◽  
Author(s):  
Alfred Walz ◽  
Federica Meloni ◽  
Ian Clark-Lewis ◽  
Vinzenz von Tscharner ◽  
Marco Baggiolini
Keyword(s):  
Respiratory Burst ◽  
Interleukin 8 ◽  
Human Neutrophils
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