@misc{oai:repo.qst.go.jp:00071815, author = {Kokubo, Toshiaki and Shimada, Yoshiya and Kakinuma, Shizuko and Ishida, Yuka and Nishimura, Yoshikazu and Oda, Hirotsugu and Wakabayashi, Hiroyuki and Yamauchi, Koji and Abe, Fumiaki and 小久保 年章 and 島田 義也 and 柿沼 志津子 and 石田 有香 and 西村 義一}, month = {Oct}, note = {There have been many reports about radioprotection. Bovine lactoferrin (LF) was one such preventive agent, and one study demonstrated that C3H/He mice fed a diet containing 0.1% LF for one month exhibited a high survival rate following exposure to whole-body X-rays at 6.8 Gy. It was thought that this result was due to the prevention of acute damage due to radiation by LF, which was also hypothesized to decrease the incidence of subsequent radiation-induced carcinogenesis. In this study, the development of X-ray-induced thymic lymphoma in mice was examined in order to understand the protective effect of LF against X-ray-induced tumors. In the study, four-week-old female B6C3F1 mice were maintained on a diet containing 2% LF and exposed to whole-body X-rays at 1.4 Gy once a week for four weeks after they reached six weeks of age. In addition, in order to examine the effects of LF on Natural killer (NK) cells after split-dose radiation exposure, dissection was performed on mice from both the control group and 2% LF diet group 24 hours, one week and three weeks after the last X-ray exposure so that the ratio of NK cells in the spleen could be analyzed. The ratio of NK cells in the LF-treated mice 24 hours after radiation exposure was found to be significantly higher than that of the control mice. When the mice were dissected six months after the last radiation exposure and examined for the frequency of macroscopic thymic lymphoma, there were no statistically significant differences between the groups, but there was a tendency for LF administration to reduce the occurrence of thymic lymphoma. Currently we are making a definitive diagnosis of thymic lymphoma based on histopathological examinations, and thereafter will calculate the final incidence of thymic lymphoma., XIth International Conference on Lactoferrin(第11回国際ラクトフェリン会議)}, title = {The usefulness of lactoferrin to protect against X-ray-induced mouse thymic lymphomas}, year = {2013} }