Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
Semey Medical University, Semey, Kazakhstan.
Sci Rep. 2021 May 26;11(1):11055. doi: 10.1038/s41598-021-90443-9.
To understand the radiation effects of the atomic bombing of Hiroshima and Nagasaki among the survivors, radiation from neutron-induced radioisotopes in soil should be considered in addition to the initial radiation directly received from the bombs. Mn, which emits both β particles and γ-rays, is one of the dominant radioisotopes created in soil by neutrons from the bomb. Thus we investigated the biological effects of internal exposure to MnO particle in the lung of male Wistar rats comparing to the effects of external Co-γ irradiation. Absorbed doses of internal irradiation of lungs were between 25 and 65 mGy in MnO-exposed animals, while the whole body doses were between 41 and 100 mGy. Animals were examined on days 3 and 61 after the exposure. There were no remarkable pathological changes related to MnO particle exposure. However, mRNA and protein expressions of aquaporin 5 increased significantly in the lung tissue on day 3 postexposure in MnO groups (by 1.6 and 2.9 times, respectively, in the highest dose group). Smad7 mRNA expression was also significantly elevated by 30% in the highest dose group of MnO. Our data demonstrated that internal exposure to MnO induced significant biological responses including gene expression changes in the lungs, while external Co-γ irradiation of 2 Gy did not show any changes.
为了了解广岛和长崎原子弹爆炸幸存者所受的辐射影响，除了直接来自炸弹的初始辐射外，还应考虑来自土壤中中子诱发放射性同位素的辐射。Mn 是由炸弹中子产生的主要放射性同位素之一，既能发射β粒子，也能发射γ射线。因此，我们研究了雄性 Wistar 大鼠肺部内暴露于 MnO 颗粒的生物学效应，并与外部 Co-γ 照射的效应进行了比较。MnO 暴露动物的肺部内照射吸收剂量在 25 至 65 mGy 之间，而全身剂量在 41 至 100 mGy 之间。动物在暴露后的第 3 天和第 61 天进行检查。MnO 颗粒暴露与肺部组织无明显的病理变化相关。然而，在暴露后第 3 天，MnO 组肺组织中水通道蛋白 5 的 mRNA 和蛋白表达显著增加（最高剂量组分别增加了 1.6 倍和 2.9 倍）。Smad7 mRNA 表达在 MnO 的最高剂量组也显著升高了 30%。我们的数据表明，内暴露于 MnO 可诱导肺部发生显著的生物学反应，包括基因表达变化，而 2 Gy 的外部 Co-γ 照射则没有显示出任何变化。
