Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
University of Caen Normandy, ARIA-CIMAP Laboratory, Campus Jules Horowitz, Caen, France.
Environ Mol Mutagen. 2021 Aug;62(7):422-427. doi: 10.1002/em.22453. Epub 2021 Aug 7.
It is well-known that the cytotoxicity and mutagenic effects of high dose rate (HDR) ionizing radiation (IR) are increased by increasing the dose but less is known about the effects of chronic low dose rate (LDR). In vitro, we have shown that in addition to the immediate interaction of IR with DNA (the direct and indirect effects), low doses and chronic LDR exposure induce endogenous oxidative stress. During elevated oxidative stress, reactive oxygen species (ROS) react with DNA modifying its structure. Here, BL6 mice were exposed to IR at LDR and HDR and were then sacrificed 3 hours and 3 weeks after exposure to examine early and late effects of IR. The levels of micronuclei, MN, were determined in bone marrow cells. Our data indicate that the effects of 200 mGy on MN-induction are transient, but 500 and 1000 mGy (both HDR and LDR) lead to increased levels of MN up to 3 weeks after the exposure.
众所周知，高剂量率（HDR）电离辐射（IR）的细胞毒性和致突变作用随着剂量的增加而增加，但对于慢性低剂量率（LDR）的影响知之甚少。在体外，我们已经表明，除了 IR 与 DNA 的直接相互作用（直接和间接作用）之外，低剂量和慢性 LDR 暴露会诱导内源性氧化应激。在氧化应激升高期间，活性氧（ROS）与 DNA 反应，改变其结构。在这里，BL6 小鼠在 LDR 和 HDR 下暴露于 IR，然后在暴露后 3 小时和 3 周处死，以检查 IR 的早期和晚期效应。在骨髓细胞中测定微核（MN）的水平。我们的数据表明，200mGy 对 MN 诱导的作用是短暂的，但 500 和 1000mGy（HDR 和 LDR 两者）导致 MN 水平增加，直至暴露后 3 周。
