Expression data in mouse liver exposed to low dose-rate radiation

Expression profiles in mouse liver exposed to long-term gamma-irradiation were examined to assess in vivo effects of low dose-rate radiation. Three groups of male C57BL/6J mice were exposed to whole body irradiation at dose-rates of 17-20 mGy/day, 0.86-1.0 mGy/day or 0.042-0.050 mGy/day for 401-485 days (cumulative doses were approximately 8 Gy, 0.4 Gy or 0.02 Gy, respectively). Expression profiles were produced for RNA isolated from irradiated individual animals and for pooled RNA from sham-irradiated 3 animals for control. The expression levels of 6 irradiated animals for each dose were compared individually with those of 2 pooled controls (3 irradiated samples to one pooled control in first and second experiments). The experiments were conducted twice at similar dose-rates. In the first experiment, three groups of 8 weeks old male C57BL/6J mice were exposed to whole body irradiation at dose-rates of either 16.6 mGy/day (H1), 0.858 mGy/day (M1) or 0.042 mGy/day (L1) for 485 days (cumulative doses were 8030 mGy, 416 mGy or 20.6 mGy, respectively). In the second experiment, the doe-rates were slightly elevated as 20.0 mGy/day (H2), 1.000 mGy/day (M2) or 0.050 mGy/day (L2) for 401 days (doses were 8015 mGy, 401 mGy or 20 mGy, respectively). A group of control unirradiated mice were set for each experiment (C1, C2).