@article{oai:repo.qst.go.jp:00047254,
 author = {Davis, Ryan and Matsumoto, Shingo and Bernardo, Marcelino and Sowers, Anastasia and Matsumoto, Kenichiro and C., Krishna Murali and B., Mitchell James and 松本 謙一郎},
 issue = {3},
 journal = {Free Radical Biology and Medicine},
 month = {Feb},
 note = {Nitroxides are a class of stable free radicals that have several biomidical applications including radioprotection and noninvasive asessment of tissue redox status. For both of these applicaitons, it is necessary to understand the in vivo biodistribution and reduction of nitroxides. In this study, magnetic resonance imaging was used to compare tissue accumulation (concentration) and reduction of two commonly studied nitroxides: the piperidine nitroxide Tempol and pyrrolidine nitroxide 3-CP. It was found that 3-CP was reduced 3 to 11 times slower (depending on the tissue) than Tempol in vivo and that maximum tissue concentration varies substantially between tissues (0.6-7.2 mM). For a given tissue, the maximum concentration usually did not vary betweeen the two nitroxides. Furthermore, using electron paramagnetic resonance spectroscopy, we showed that the nitroxide reduction rate depends only weakly on cellular pO2 in the oxygen range expected in vivo. These observations, taken with the marked variation in nitorxide reductin rates observed between tissues, suggest that tissue pO2 is not a major determinant of the nitoride reduction rate in vivo. For the purpose of redox imaiging, 3-CP was shown to be an optimal choice based on the achievable concentrations and bioreduction observed in vivo.},
 pages = {459--468},
 title = {Magnetic resonance imaging of organic contrast agents in mice: capturing the whole-body redox landscape},
 volume = {50},
 year = {2011}
}