A spin-trapping database implemented on the IBM PC/AT

Li, Anson S. W.; Cummings, K. B.; Roethling, H Peter; Buettner, Garry R.; Chignelq, Colin F

doi:10.1016/0022-2364(88)90329-0

Cited by 72 publications

(77 citation statements)

References 10 publications

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“…The major part of this ESR spectrum is SOD-sensitive ( Figure 3F) and exhibits a pattern characteristic of the DMPO/ • OOH radical adduct. Computer analysis and simulation of the ESR spectrum ( Figure 3G) showed that DMPO/ • OOH accounts for 91.2 % of the composite spectrum with hyperfine coupling constant values a N = 14.1 G, , and , which are similar to those previously published [23][24][25]. Another minor radical species (8.8 %) was attributed to the DMPO/ • OH adduct, with hyperfine coupling constants of .…”

Section: Photo-induced Production Of Superoxidesupporting

confidence: 81%

Studies on the Photosensitized Reduction of Resorufin and Implications for the Detection of Oxidative Stress with Amplex Red

Zhao¹,

Ranguelova²,

Jiang³

et al. 2010

Free Radical Biology and Medicine

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The photosensitized reduction of resorufin (RSF), the fluorescent product of Amplex Red, was investigated using electron spin resonance (ESR), optical absorption/fluorescence, and oxygen consumption measurements. Anaerobic reaction of RSF in the presence of the electron donor reduced nicotinamide adenine dinucleotide (NADH) demonstrated that during visible light irradiation (λ > 300 nm), RSF underwent one-electron reduction to produce a semiquinoneiminetype anion radical (RSF •− ) as demonstrated by direct ESR. Spin-trapping studies of incubations containing RSF, 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and NADH demonstrate, under irradiation with visible light, the production of the superoxide dismutase (SOD)-sensitive DMPO/ • OOH adduct. Both absorption and fluorescence spectra of RSF in the presence of NADH demonstrated that the RSF •− was further reduced during irradiation with formation of its colorless dihydroquinoneimine form, dihydroresorufin (RSFH 2 ). Both RSF •− and RSFH 2 , when formed in an aerobic system, are immediately oxidized by oxygen, which regenerates the dye and forms superoxide. Oxygen consumption measurements with a Clark-type oxygen electrode show that molecular oxygen is consumed in a light-dependent process. The suppression of oxygen consumption by addition of SOD or catalase further confirms the production of superoxide and hydrogen peroxide.

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Section: Photo-induced Production Of Superoxidesupporting

confidence: 81%

Studies on the Photosensitized Reduction of Resorufin and Implications for the Detection of Oxidative Stress with Amplex Red

Zhao¹,

Ranguelova²,

Jiang³

et al. 2010

Free Radical Biology and Medicine

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“…The major radical adduct with hyperfine coupling constants a N =16.06 G, a H =2.87 G, and a 13C =4.86 G (Fig. 2C) was assigned to POBN/ ·13 CH 3 based upon comparison of these splitting constants with the literature [28][29][30][31]. The unequivocal identification of the POBN/methyl radical adduct in the bile of rats 1 h after CdCl 2 administration indicates production of the hydroxyl radical.…”

Section: Detection Of Cd-induced Radicals In Rat Bilementioning

confidence: 88%

“…2D) were a N =15.62 G and a H =2.97 G (n=4). Radical adducts with these coupling constants are formed during lipid peroxidation and by the one-electron reductive decomposition of lipid hydroperoxides [28][29][30][31]. Therefore, this radical was assigned as POBN/L.…”

Section: Detection Of Cd-induced Radicals In Rat Bilementioning

confidence: 99%

Cadmium generates reactive oxygen- and carbon-centered radical species in rats: Insights from in vivo spin-trapping studies

Liu

Qian

Guo

et al. 2008

Free Radical Biology and Medicine

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Cadmium (Cd) is a known industrial and environmental pollutant. In the present work, an in vivo spintrapping technique was used in conjunction with electron spin resonance (ESR) spectroscopy to investigate free radical generation in rats following administration of cadmium chloride (CdCl 2 , 40 µmol/kg) and the spin trapping agent α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN, 1 g/kg). In Cd-treated rats, POBN radical adducts were formed in the liver, were excreted into the bile, and exhibited an ESR spectrum consistent with a carbon-centered radical species probably derived from endogenous lipids. Isotope substitution of dimethyl sulfoxide [(CH 3 ) 2 SO] with 13 C demonstrated methyl radical formation (POBN/* 13 CH 3 ). This adduct indicated the production of hydroxyl radical, which reacted with [( 13 CH 3 ) 2 SO] to form * 13 CH 3 , which then reacted with POBN to form POBN/ * 13 CH 3 . Depletion of hepatic glutathione by diethyl maleate significantly increased free radical production, whereas inactivation of Kupffer cells by gadolinium chloride and chelation of iron by desferal inhibited it. Treatment with the xanthine oxidase inhibitor allopurinol, the catalase inhibitor aminobenzotriazole, or the cytochrome P450 inhibitor 3-amino-1,2,4-triazole had no effect. This is the first study to show Cd generation of reactive oxygen and carbon-centered radical species by involvement of both iron mediation through iron-catalyzed reactions and activation of Kupffer cells, the resident liver macrophages.

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“…Exposure to UV radiation resulted in a triplet of doublets as well as the ascorbate free radical signal. The hypefine splittings of the POBN adduct were aN = 15.62 G and aH = 3.1 G, possibly indicating a carbon dioxide radical anion (21,22). This signal was very weak, thus further spintrapping experiments were done using DMPO.…”

mentioning

confidence: 99%

EPR Detection of Free Radicals in UV‐lrradiated Skin: Mouse Versus Human

Jurkiewicz

Buettner

1996

Photochem & Photobiology

131

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Ultraviolet radiation produces free radicals in Skh-1 mouse skin, contributing to photoaging and carcinogenesis. If a mouse model is a general indicator of free radical processes in human skin photobiology, then radical production observed in mouse and human skin should be directly comparative. In this work we show that UV radiation (A > 300 nm, 14 pW/cmZ W B ; 3.5 mW/cmz UVA) increases the ascorbate free radical (Ax'-) electron paramagnetic resonance (EPR) signal in both Skh-1 mouse skin (45%) and human facial skin biopsies (340%). Visible light (A > 400 nm; 0.23 mW/cm* UVA) also increased the Ax*-signal in human skin samples (45%) but did not increase baseline mouse Asc*-, indicating that human skin is more susceptible to free radical formation and that a chromophore for visible light may be present. Using EPR spin-trapping techniques, UV radiation produced spin adducts consistent with trapping lipid alkyl radicals in mouse skin (a-[4-pyridyl l-oxidel-N-terf-butyl nitrondalkyl radical adduct; aN = 15.56 G and a" = 2.70 G) and lipid akoxyl radicals in human skin (53-dimethylpyrroline-l-oxiddalkoxyl radical adduct; aN = 14.54 G and aH = 16.0 G). Topical application of the iron chelator Desferal' to human skin significantly decreases these radicals (-SO%), indicating a role for iron in lipid peroxidation; Desferal has previously been shown to decrease radical production in mouse skin. This work supports the use of the Skh-1 mouse as a predictive tool for free radical formation in human skin. These results provide the first direct evidence for W radiationinduced free radical formation at near physiological temperatures in human skin and suggest that iron chelators may be useful as photoprotective agents.

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A spin-trapping database implemented on the IBM PC/AT

Cited by 72 publications

References 10 publications

Studies on the Photosensitized Reduction of Resorufin and Implications for the Detection of Oxidative Stress with Amplex Red

Studies on the Photosensitized Reduction of Resorufin and Implications for the Detection of Oxidative Stress with Amplex Red

Cadmium generates reactive oxygen- and carbon-centered radical species in rats: Insights from in vivo spin-trapping studies

EPR Detection of Free Radicals in UV‐lrradiated Skin: Mouse Versus Human

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