title: Separable detection of lipophilic- and hydrophilic-phase free radicals from the ESR spectrum of nitroxyl radical in transient MCAO mice.
abstract: Free radicals are believed to be key factors that promote ischemia reperfusion injury in the brain. This study used the characteristic spectrum of methoxycarbonyl-PROXYL to detect free radical reactions in hydrophilic and lipophilic compartments in a transient middle cerebral artery occlusion (MCAO) mouse model. Methoxycarbonyl-PROXYL, which has a high water/octanol partition coefficient, allows the detection of nitroxyl radical in both compartments simultaneously. Free radicals generation was analysed from the enhanced ESR signal decay rate of methoxycarbonyl-PROXYL. The signal decay rate in the lipidic compartment was significantly enhanced 1 h after reperfusion following MCAO. The enhanced signal decay rate was significantly suppressed by Trolox. The accumulation of lipid peroxidation products increased by 6 h post-reperfusion and was suppressed by methoxycarbonyl-PROXYL or Trolox. These results demonstrate that information pertaining to different sites of free radical generation in vivo can be obtained simultaneously and that lipid-derived radicals are generated in transient MCAO mice.
authors.affiliation: Department of REDOX Medicinal Science, Faculty of Pharmaceutical Sciences, Kyushu University,Fukuoka, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Yamato
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shiba
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Yamada
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Watanabe
authors.forename: Hideo
authors.initials: H
authors.lastname: Utsumi
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002839:Chromans / Q000494:pharmacology; D003497:Cyclic N-Oxides / Q000737:chemistry; D004195:Disease Models, Animal; D004578:Electron Spin Resonance Spectroscopy; D020244:Infarction, Middle Cerebral Artery / Q000188:drug therapy / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D051379:Mice; D009589:Nitrogen Oxides / Q000378:metabolism*; D000442:Octanols / Q000737:chemistry; D011759:Pyrrolidines / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013113:Spin Labels; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000975:Antioxidants; D002839:Chromans; D003497:Cyclic N-Oxides; C109806:MCPROXYL; D009589:Nitrogen Oxides; D000442:Octanols; D011759:Pyrrolidines; D012997:Solvents; D013113:Spin Labels; D014867:Water; C039900:nitroxyl; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid