scholarly journals Presence of the distinct systems responsible for superoxide anion and hydrogen peroxide generation in red tide phytoplankton Chattonella marina and Chattonella ovata

2007 ◽  
Vol 29 (3) ◽  
pp. 241-247 ◽  
Author(s):  
Daekyung Kim ◽  
Takuji Nakashima ◽  
Yukihiko Matsuyama ◽  
Yoshimi Niwano ◽  
Kenichi Yamaguchi ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Anion ◽  
Red Tide ◽  
Chattonella Marina ◽  
Hydrogen Peroxide Generation

Mechanism of superoxide anion generation in the toxic red tide phytoplankton Chattonella marina: possible involvement of NAD(P)H oxidase

2000 ◽  
Vol 1524 (2-3) ◽  
pp. 220-227 ◽  
Author(s):  
Daekyung Kim ◽  
Atsushi Nakamura ◽  
Tarou Okamoto ◽  
Nobukazu Komatsu ◽  
Tatsuya Oda ◽  
...  
Keyword(s):  
Superoxide Anion ◽  
Red Tide ◽  
Chattonella Marina ◽  
Superoxide Anion Generation

scholarly journals Involvement of an NAD(P)H oxidase-like enzyme in superoxide anion and hydrogen peroxide generation by rat type II cells

Thorax ◽  
1997 ◽  
Vol 52 (5) ◽  
pp. 465-471 ◽  
Author(s):  
R. J. van Klaveren ◽  
C. Roelant ◽  
M. Boogaerts ◽  
M. Demedts ◽  
B. Nemery
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Anion ◽  
Type Ii Cells ◽  
Type Ii ◽  
Hydrogen Peroxide Generation

Production of superoxide anion and hydrogen peroxide by the red tide dinoflagellate Karenia mikimotoi

2004 ◽  
Vol 97 (3) ◽  
pp. 212-215 ◽  
Author(s):  
Yasuhiro Yamasaki ◽  
Dae-Il Kim ◽  
Yukihiko Matsuyama ◽  
Tatsuya Oda ◽  
Tsuneo Honjo
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Anion ◽  
Red Tide ◽  
Karenia Mikimotoi

scholarly journals Discrete Generation of Superoxide and Hydrogen Peroxide by T Cell Receptor Stimulation

2002 ◽  
Vol 195 (1) ◽  
pp. 59-70 ◽  
Author(s):  
Satish Devadas ◽  
Luba Zaritskaya ◽  
Sue Goo Rhee ◽  
Larry Oberley ◽  
Mark S. Williams
Keyword(s):  
Hydrogen Peroxide ◽  
T Cell ◽  
T Cell Receptor ◽  
Superoxide Anion ◽  
Fas Ligand ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Activated T Cells ◽  
Tcr Signals ◽  
Hydrogen Peroxide Generation

Receptor-stimulated generation of reactive oxygen species (ROS) has been shown to regulate signal transduction, and previous studies have suggested that T cell receptor (TCR) signals may involve or be sensitive to ROS. In this study, we have shown for the first time that TCR cross-linking induced rapid (within 15 min) generation of both hydrogen peroxide and superoxide anion, as defined with oxidation-sensitive dyes, selective pharmacologic antioxidants, and overexpression of specific antioxidant enzymes. Furthermore, the data suggest the novel observation that superoxide anion and hydrogen peroxide are produced separately by distinct TCR-stimulated pathways. Unexpectedly, TCR-stimulated activation of the Fas ligand (FasL) promoter and subsequent cell death was dependent upon superoxide anion, but independent of hydrogen peroxide, while nuclear factor of activated T cells (NFAT) activation or interleukin 2 transcription was independent of all ROS. Anti-CD3 induced phosphorylation of extracellular signal–regulated kinase (ERK)1/2 required hydrogen peroxide generation but was unaffected by superoxide anion. Thus, antigen receptor signaling induces generation of discrete species of oxidants that selectively regulate two distinct redox sensitive pathways, a proapoptotic (FasL) and a proliferative pathway (ERK).

Oxidation of hydrogen peroxide at the dropping mercury electrode

1984 ◽  
Vol 49 (10) ◽  
pp. 2320-2331 ◽  
Author(s):  
Miroslav Březina ◽  
Martin Wedell
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Anion ◽  
Ph Value ◽  
Mercury Electrode ◽  
Electrode Process ◽  
Electrochemical Processes ◽  
Dropping Mercury Electrode ◽  
Oxidation Of Hydrogen ◽  
Decreasing Ph ◽  
Rate Controlling Step

Reduction of oxygen and oxidation of hydrogen peroxide at the dropping mercury electrode are electrochemical processes strongly influenced both by the pH value and the anions in solution. With decreasing pH, both processes become irreversible, especially in the presence of anions with a negative φ2 potential of the diffusion part of the double layer. In the case of irreversible oxygen reduction, the concept that the rate-controlling step of the electrode process is the acceptance of the first electron with the formation of the superoxide anion, O2-, was substantiated. Oxidation of hydrogen peroxide becomes irreversible at a lower pH value than the reduction of oxygen. The slowest, i.e. rate-controlling step of the electrode process in borate buffers at pH 9-10 is the transfer of the second electron, i.e. oxidation of superoxide to oxygen.

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