title: Non-invasive measurement of melanin-derived radicals in living mouse tail using X-band EPR.
abstract: The aim of this experiment is to measurein vivogeneration of melanin-derived radicals non-invasively, as a quantifiable index of radio-biological effect. Melanin-derived radicals in a living intact mouse tail tip were non-invasively measured in very simple way using an X-band electron paramagnetic resonance spectrometer. Colored mouse strains, C57BL/6NCr, BDF1, and C3H/He, have clear EPR signal corresponding to melanin-derived radicals in the tail tip; however, albino mouse strains, BALB/cCr, ddY, ICR, have no EPR signals. An X-ray fraction of 2 Gy/day (1 Gy/min) was repeatedly irradiated to a C3H/He mouse tail skin every Monday to Friday for 4 weeks. In comparison to before starting irradiation, the C3H/He mouse tail skin became darker, like a suntan. The melanin-derived radicals in C3H/He mouse tail skin were increased in association with X-ray fractions. Melanin-derived radicals in mouse tail skin can be readily and chronologically measurable by using X-band EPR spectrometer, and can be a marker for a radiobiological effect in the skin.
authors.affiliation: Radio-Redox-Response Research Team, Advanced Particle Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555, Japan; Department of Biomolecular Science, Toho University Graduate School of Science, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Ogawa
authors.affiliation: Radio-Redox-Response Research Team, Advanced Particle Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Ueno
authors.affiliation: Research Program for the Application of Heavy Ions in Medical Sciences, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555, Japan.
authors.forename: Emiko
authors.initials: E
authors.lastname: Sekine-Suzuki
authors.affiliation: Radio-Redox-Response Research Team, Advanced Particle Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Nakanishi
authors.affiliation: Radio-Redox-Response Research Team, Advanced Particle Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555, Japan; Department of Biomolecular Science, Toho University Graduate School of Science, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan; Graduate School of Advanced Integration Science, Chiba University, 1-33 Yayoi-chou, Inage-ku, Chiba-shi, Chiba 263-8522, Japan.
authors.forename: Ken-Ichiro
authors.initials: KI
authors.lastname: Matsumoto
authors.affiliation: Department of Biomolecular Science, Toho University Graduate School of Science, 2-2-1 Miyama, Funabashi-shi, Chiba 274-8510, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Fujisaki
keywords: X-ray irradiation; electron paramagnetic resonance; melanin-derived radicals; non-invasive measurement; radio-biological effect