著者
常岡 和子 HIROSHI ISHIHARA ALEXANDER BORRISOV DIMCHEV KOJI NOMOTO TERUO YOKOKURA MIKIO SHIKITA
出版者
Journal of Radiation Research 編集委員会
雑誌
Journal of Radiation Research (ISSN:04493060)
巻号頁・発行日
vol.35, no.3, pp.147-156, 1994-09-15 (Released:2006-05-19)
参考文献数
25
被引用文献数
9 14

A single subcutaneous injection of a preparation of heat-killed Lactobacillus casei (LC 9018), given before or after irradiation, significantly increased the survival rate of mice that had received 8.5-Gy 137Cs whole-body γ-irradiation. A similar radioprotective effect was observed when LC 9018 was administered within the period from 2 days before irradiation to 9 h after irradiation, the pre-irradiation treatment being slightly better than the post-irradiation treatment. Increases in the weight of the spleen and in the number of endogenous spleen colonies on days 8 and 12 after irradiation suggested that the radioprotective effect was based on enhanced recovery of hematopoietic tissues. The activity of macrophage colony-stimulating factor (M-CSF) in serum was rapidly increased by the treatment and was maintained at the elevated level for 13 days. At the same time, an increased level of M-CSF mRNA was detected in the livers of the treated mice. However, LC 9018 failed to save the lives of mice when administered 3 days after irradiation, although it increased serum M-CSF as effectively as noted above. The small advantage of the pre-irradiation over the post-irradiation treatment was not explained by the increases of metallothionein in the hematopoietic tissues of the treated mice.