@misc{oai:repo.qst.go.jp:00070490,
 author = {Matsumoto, Kenichiro and Nakanishi, Ikuo and Indo, Hiroko and Majima, Hideyuki and 松本 謙一郎 and 中西 郁夫 and 馬嶋 秀行},
 month = {Sep},
 note = {Dose estimation of low dose irradiation is difficult, because almost no marked symptom can be observed by low dose irradiation. To find possible index for low dose irradiation, effect of low dose X-ray irradiation to melanin radical in mouse tail skin was investigated.
Female 7-week-old C3H mice were habituated for a week, and then hair was sampled by electric hair clipper from the back. An aliquot (~10 mg) of the hair sample was weighed accurately, stuffed in a plastic tube, and then measured by X-band (9.4 GHz) electron paramagnetic resonance (EPR) spectrometer. The mice were irradiated by X-ray with dose of 100 mGy/day on 5 days/week (Mon to Fri) for 12 weeks. Again, hair was sampled from the back after 12-week irradiation. The 2 cm tip of the tail was sampled and lyophilized. The hair and tail samples were measured by X-band EPR spectrometer. Next, 4-week irradiation experiment was carried out, with 10, 100, 500 mGy/day on 5 days/week.
After the X-ray irradiation at 100 mGy/day for 12 weeks, no difference was obtained for melanin radical in hair before and after irradiation. In the next experiment, X-ray irradiation at 500 mGy/day for 4 weeks makes melanin radical in hair higher compared to non irradiated group, while the amount of melanin radical was reduced compared to before irradiation. Hair melanin radical may be responsible for X-ray irradiation but the baseline amount can be variable; however, the melanin radical amount in the tail skin was increased dose dependently. Melanin radical in skin can be a temporal marker for low dose irradiation., 2011 Kagoshima Congress (Joint Meeting of 5th SFRR-Asia, 8th ASMRM, and 11th J-mit)},
 title = {Increasing Melanin Radical in Mouse Skin by Low Dose X-Ray Irradiation},
 year = {2011}
}