Inter-strain variation of skin reaction among three strains of mice after fractionated irradiation.

[Purpose]To clarify the mechanism the heterogeneity in the response to ionizing irradiation arising from a genetic variation between individual humans, we here investigated the irradiated skin reaction of mice fractionated irradiation with comparison of the results after single dose irradiation setting.[Material and Method]Female mice, 12 weeks old of the inbred strains C3H/HeMs, C57BL/6J, A/J were used through experiments. After Cs-137 gamma rays irradiated 10 fraction- 3, 4, 5, 6 Gy/ 12 days on right-hind legs, and comparison of fractionated irradiation with single dose. [Results]1. Radiosensitivity of a group of fractionated radiation was C3H/HeMs< A/J< C57BL/6J. 2. Latent periods appeared the same point in a group of single dose, but a group of fractionated radiation was different among three strains or irradiated dose. 3. Peak skin reaction score was exhibited dose dependency, although fractionated irradiation groups was low compared with single dose groups, the strain difference was not observed in each irradiation group. But low dose was not displayed dose dependency, the strain difference observed.[Discussion] Inter-strain differences were observed in radiation susceptibility among three strains of mice using the functional endpoint of skin reaction after local fractionated irradiation. In particular, peak skin reaction score in latent periods and low dose observed strain difference.日本放射線影響学会第４６回大