@article{oai:repo.qst.go.jp:00042950,
 author = {Nose, Masako and Bing, Wang and Itsukaichi, Hiromi and Yukawa, Osami and Hayata, Isamu and Yamada, Takeshi and Ohyama, Harumi and 能勢 正子 and 王 冰 and 五日市 ひろみ and 湯川 修身 and 早田 勇 and 山田 武 and 大山 ハルミ},
 journal = {Radiation Research},
 month = {},
 note = {Exposing mice to 0.5 Gy X rays 2 weeks before lethal irradiation has been reported to induce marked radioresistance and to rescue them from hematopoietic death. Here we examined effects of the 0.5-Gy pre-exposure on hematological changes in C57BL mice that were lethally irradiated with 6.5 Gy X rays. Approximately 77% of pre-exposed mice survived 30 days after this irradiation, whereas 80% of mice that did not receive this pre-exposure died by day 20. However, regardless of the pre-exposure, peripheral blood cell counts decreased markedly by day 3 and reached a nadir at day 20. CFU-S in femur and CFU-GM in spleen had started to recover at day 10 and 14, respectively, but recovery of functional peripheral blood cells occurred later. The effect of pre-exposure on survival was altered by OK432, a bioresponse modifier; the effect　depended on the timing of its administration. OK432 given 2 days before 0.5 Gy enhanced the protective effect of pre-exposure, resulting in the survival of 97% of the mice. In contrast, injection of OK432 1 day before or 2 days after pre-exposure led to 100% mortality. Thus the
survival-promoting effect of 0.5 Gy could be altered by OK432. The OK432-induced changes in the survival of mice could not be attributed solely to hematological changes, as shown by blood cell counts and progenitor cell contents. These results suggest that radioresistance induced by pre-exposure to 0.5 Gy X rays is not stable, but rather varies with the physiological conditions, and can be modulated by factors such as OK432.},
 pages = {195--204},
 title = {Rescue of lethally irradiated mice from hematopoietic death by pre-exposure to 0.5 Gy X rays without recovery from peripheral blood cell depletion and its modification by OK432.},
 volume = {156},
 year = {2001}
}