@misc{oai:repo.qst.go.jp:00067550,
 author = {Takeshita, Keizo and Cuiping, Chi and Hirata, Hiroshi and Ono, Mitsuhiro and Suzaki, Hitoshi and Ozawa, Toshihiko and 竹下 啓蔵 and 池 翠萍 and 小野 光弘 and 小澤 俊彦},
 month = {Oct},
 note = {Exposure to ultraviolet (UV) light leads to various injuries such as sunburn, inflammation, aging, cancer, etc.  There have been little reports about in vivo evidence of generation of free radicals including oxygen radicals during exposure to UV light, although free radicals may be involved in those injuries.  In this study, induction of radical reaction was examined in skin of living mouse under UV light by using in vivo ESR spectroscopy with a nitroxyl radical, 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl (CP), as a redox probe.  An aqueous solution of CP was injected intravenously to an anesthetized hairless mouse, and in vivo ESR spectra of the probe were recorded at the dorsal region of the mice with a surface-coil-type resonator.  ESR signal of CP increased up to a few minutes after the injection and then decreased.  The rate of the signal decay increased by irradiation with UV light (UV-A+B).  The increase was statistically significant.  The increase of signal decay rate was suppressed by pre-administration of a spin trapping reagent, N-t-butyl-a-phenylnitrone (PBN), while PBN did not change the decay rate for non-irradiated mouse.  There was no relationship between the signal decay rate and physiological parameters (blood velocity and blood mass in skin and body surface temperature).  These observations suggest that the enhanced decay of the nitroxyl ESR signal is related to the generation of radicals under UV light irradiation.  The radical scavenging activity of some antioxidants was assessed with this technique., Fifth AFMC International Medicinal Chemistry Symposium (AIMECS 03)},
 title = {In vivo ESR measurement of radical generation in mouse skin under ultraviolet light},
 year = {2003}
}