Effect of dose and dose rate of gamma irradiation on the formation of micronuclei in bone marrow cells isolated from whole-body-irradiated mice

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.

Keywords: DNA damage; dose rate; ionizing radiation; micronuclei; systemic effects.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone Marrow Cells / pathology*
  • Bone Marrow Cells / radiation effects
  • Dose-Response Relationship, Radiation
  • Female
  • Gamma Rays / adverse effects*
  • Mice
  • Mice, Inbred C57BL
  • Micronuclei, Chromosome-Defective / radiation effects*
  • Micronucleus Tests
  • Whole-Body Irradiation / adverse effects*