Highly reactive oxygen species: detection, formation, and possible functions

Abstract

The so-called reactive oxygen species (ROS) are defined as oxygen-containing species that are more reactive than O(2) itself, which include hydrogen peroxide and superoxide. Although these are quite stable, they may be converted in the presence of transition metal ions, such as Fe(II), to the highly reactive oxygen species (hROS). hROS may exist as free hydroxyl radicals (HO·), as bound ("crypto") radicals or as Fe(IV)-oxo (ferryl) species and the somewhat less reactive, non-radical species, singlet oxygen. This review outlines the processes by which hROS may be formed, their damaging potential, and the evidence that they might have signaling functions. Since our understanding of the formation and actions of hROS depends on reliable procedures for their detection, particular attention is given to procedures for hROS detection and quantitation and their applicability to in vivo studies.

Reactive oxygen species and plant resistance to fungal pathogens

“…In the next section, we have briefly summarised the most common approaches used and indicated some recent publications where they have been applied. The reader is referred to several useful reviews on methodological aspects and associated difficulties and limitations concerning ROS detection (Freinbichler et al, 2011;Nauseef, 2014;Winterbourn, 2014;Zulfugarov et al, 2011).…”

First-in-class thyrotropin-releasing hormone (TRH)-based compound binds to a pharmacologically distinct TRH receptor subtype in human brain and is effective in neurodegenerative models

“…The formation of highly reactive oxygen species (hROS), which provides a measure of oxidative stress commonly associated with the pathogenesis of many neurodegenerative disorders (Cavalli et al, 2008;Freinbichler et al, 2011;Zhou et al, 2008), can be evoked in a dose-dependent manner by local application of an excitotoxic concentration of KA into rat striatum. hROS can be sensitively quantified as OH-TA, the hydroxylated derivative of sodium terephthalate (TA 2-) (Freinbichler et al, 2011(Freinbichler et al, , 2008.…”

“…hROS can be sensitively quantified as OH-TA, the hydroxylated derivative of sodium terephthalate (TA 2-) (Freinbichler et al, 2011(Freinbichler et al, , 2008. This method was used to assess the ability of JAK4D to protect against in vivo free radical formation induced by intrastriatal administration of KA (1 mM) during brain microdialysis.…”

“…Appoximately 48 h later, microdialysis experiments were performed on freely-moving rats, always starting at 9:00 am, by inserting the microdialysis probe (4mm exposed surface; CMA/Microdialysis AB, Stockholm, Sweden) into the guide cannula. The perfusion fluid, artificial cerebrospinal fluid (aCSF), comprised: 140 mM NaCl, 3 mM KCl, 1.2 mM CaCl 2 , 1.0 mM MgCl 2 , 1.2 mM Na 2 HPO 4 , 0.27 mM NaH 2 PO 4 and 7.2 mM glucose (pH 7.4), plus 1 mM sodium terephthalate (TA 2-) used as a chemical trap for highly reactive oxygen species (hROS) (Freinbichler et al, 2011).…”

“…just before KA (1 mM) was applied to the neostriatum for 20 min from 100-120 min through the dialysis probe to the two KA-treated groups. Reverse phase high pressure liquid chromatography analysis of 2-hydroxyterephthalate (OH-TA) in microdialysates was carried out using a Shimadzu instrument (Italia S.r.l., Milan, Italy) with a fluorescence detector (λex = 315 nm; λem = 435 nm) (Freinbichler et al, 2011).…”