@article{oai:repo.qst.go.jp:00046950,
 author = {Ueno, Megumi and Nyui, Minako and Nakanishi, Ikuo and Anzai, Kazunori and Ozawa, Toshihiko and Ken-ichiro, Matsumoto and Uto, Yoshihiro and Megumi, Ueno and Minako, Nyui and Ikuo, Nakanishi and Kazunori, Anzai and Toshihiko, Ozawa and Kenichiro, Matsumoto},
 issue = {2},
 journal = {Journal of Clinical Biochemistry and Nutrition},
 month = {Mar},
 note = {The scavenging activity of rat plasma against hyperthermia-induced reactive oxygen species was tested. The glutathione dependent reduction of a nitroxyl radical, 4-hydroxyl-2,2,6,6-tetramethylpiperidineNoxyl, which was restricted by adding superoxide dismutase or by deoxygenating the reaction mixture,
was applied to an index of superoxide (O2•−) generation. A reaction
mixture containing 0.1 mM 4hydroxyl2,2,6,6tetramethylpiperidine-N-oxyl and 1 mM glutathione was prepared using 100 mM phosphate buffer containing 0.05 mM diethylenetriaminepenta acetic acid. The reaction mixture was kept in a screwtop vial and incubated in a water bath at 37 or 44°C. The time course of the electron paramagnetic resonance signal of 4-hydroxyl-2,2,6,6-tetramethylpiperidineNoxyl in the reaction mixture was measured by an X-band EPR spectrometer (JEOL, Tokyo, Japan). When the same experiment was performed using rat plasma instead of 100 mM PB, the glutathionedependent reduction of 4-hydroxyl-2,2,6,6-tetramethylpiperidine-N-oxyl, i.e., generation of O2•−, was not obtained. Only the firstorder decay reduction of 4hydroxyl
2,2,6,6tetramethylpiperidineNoxyl, which indicates direct reduction of 4hydroxyl2,2,6,6tetramethylpiperidineNoxyl, was obtained in rat plasma. Adding 0.5% albumin to the phosphate buffer reaction mixture could almost completely inhibit O2•− generation at 37°C. However, addition of 0.5% albumin could not
inhibit O2•− generation at 44°C, i.e., hyperthermic temperature. Ascorbic acid also showed inhibition of O2•− generation by 0.01 mM at 37°C, but 0.02 mM or more could inhibit O2•− generation at 44°C. A higher concentration of ascorbic acid showed first order reduction, i.e., direct oneelectron reduction, of TEMPOL.
Hyperthermiainduced O2
•− generation in rat plasma can be mostly
inhibited by albumin and ascorbic acid in the plasma.},
 pages = {75--80},
 title = {Scavenging of reactive oxygen species Induced by hyperthermia in biological fluid},
 volume = {54},
 year = {2014}
}