TY - JOUR
T1 - Application of a trityl-based radical probe for measuring superoxide
AU - Rizzi, Cëcile
AU - Samouilov, Alexandre
AU - Kumar Kutala, Vijay
AU - Parinandi, Narasimham L.
AU - Zweier, Jay L.
AU - Kuppusamy, Periannan
PY - 2003/12/15
Y1 - 2003/12/15
N2 - The use of triarylmethyl (trityl) free radical, TAM OX063, for detection of superoxide in aqueous solutions by electron paramagnetic resonance (EPR) spectroscopy was investigated. TAM is paramagnetic (EPR active), highly soluble in water and exhibits a single sharp EPR peak in aqueous media. It is also highly stable in presence of many oxidoreductants such as ascorbate and glutathione that are present in the biological systems. TAM reacts with superoxide with an apparent second order rate constant of 3.1 × 10 3 M-1 s-1. The specific reactivity of TAM with superoxide, which leads to loss of EPR signal, was utilized to detect the generation of superoxide in various chemical (light/riboflavin/electron/donor), enzymatic (xanthine/xanthine oxidase), and cellular (stimulated neutrophils) model systems. The changes in the EPR line-width, induced by molecular oxygen, were utilized in the simultaneous determination of consumption of oxygen in the model systems. The effects of flux of superoxide and concentration of TAM on the efficiency of detection of superoxide were studied. The use of TAM for detection of superoxide offers unique advantages namely, (i) the utilization of very low concentration of the probe, (ii) its stability to bioreduction, and (iii) its use in the simultaneous determination of concentrations of superoxide and oxygen.
AB - The use of triarylmethyl (trityl) free radical, TAM OX063, for detection of superoxide in aqueous solutions by electron paramagnetic resonance (EPR) spectroscopy was investigated. TAM is paramagnetic (EPR active), highly soluble in water and exhibits a single sharp EPR peak in aqueous media. It is also highly stable in presence of many oxidoreductants such as ascorbate and glutathione that are present in the biological systems. TAM reacts with superoxide with an apparent second order rate constant of 3.1 × 10 3 M-1 s-1. The specific reactivity of TAM with superoxide, which leads to loss of EPR signal, was utilized to detect the generation of superoxide in various chemical (light/riboflavin/electron/donor), enzymatic (xanthine/xanthine oxidase), and cellular (stimulated neutrophils) model systems. The changes in the EPR line-width, induced by molecular oxygen, were utilized in the simultaneous determination of consumption of oxygen in the model systems. The effects of flux of superoxide and concentration of TAM on the efficiency of detection of superoxide were studied. The use of TAM for detection of superoxide offers unique advantages namely, (i) the utilization of very low concentration of the probe, (ii) its stability to bioreduction, and (iii) its use in the simultaneous determination of concentrations of superoxide and oxygen.
KW - EPR
KW - Free radicals
KW - Neutrophils
KW - Oximetry
KW - Riboflavin
KW - Spin trapping
KW - Superoxide
KW - Trityl radical
KW - Xanthine oxidase
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UR - http://www.scopus.com/inward/citedby.url?scp=0347627466&partnerID=8YFLogxK
U2 - 10.1016/j.freeradbiomed.2003.09.014
DO - 10.1016/j.freeradbiomed.2003.09.014
M3 - Article
C2 - 14680684
AN - SCOPUS:0347627466
SN - 0891-5849
VL - 35
SP - 1608
EP - 1618
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
IS - 12
ER -