Verification of a dose rate-responsive dynamic equilibrium model on radiation-induced mutation frequencies in mice

Abstract

Purpose: We have proposed a mathematical model (WAM model) expressing increment of the dose-rate dependent mutation frequency caused by artificial radiations. In this model, it is defined that the pool of mutant cells in dynamic equilibrium in organisms. We verified the accuracy of the WAM prediction of mutation frequency in mice.

Materials and methods: The theoretical values calculated by the WAM model were compared with the experimental values obtained from the large mouse genetics program at the Oak Ridge National Laboratory (ORNL).

Results: Most of all the theoretical values in acute and chronic irradiation conditions nearly coincided with the experimental values. However, the theoretical value of the chronic conditions at the dose-rate of 0.8 R/min was significantly higher than its experimental value. This discordance was able to be minimized in the WAM assumption, when the period from the end of exposure to start mating was two weeks longer.

Conclusions: As a result of comparison between experimental and theoretical data, the certainty of the WAM model was confirmed in mice and it was shown that the genetic influence varies depending on the dose-rate.

Keywords:

• Low-dose-rate radiation
• mutation
• theoretical model

Acknowledgements

We are grateful to Dr. Yoshiharu Yonekura, Dr. Wolfgang Weiss and all members of the committee of International workshop on the biological effects of radiation (BER2018, OSAKA) for give us an opportunity to present our work.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by the Ministry of Education, Science, Sports and Culture, Grant-in-Aid for Scientific Research (B), 2016-2019 (16H04637, Takahiro Wada) and Grant-in Aid for Challenging Exploratory Research, 2015-2017 (15K14291, Masako Bando).

Notes on contributors

Yuichi Tsunoyama

Dr. Yuichi Tsunoyama Ph.D., is assistant professor of Radioisotope Research Center, Agency for Health, Safety and Environment, Kyoto University. His research topics are biological effect of radiation at the molecular and cellular level.

Kazuyo Suzuki

Dr. Kazuyo Suzuki M.D., Ph.D., is program-specific assistant professor of Preemptive Medicine and Lifestyle-related Disease Research Center, Kyoto University. Her research interests lie in nutrition science, metabolism, and preventive medicine.

Miwako Masugi-Tokita

Dr. Miwako Masugi-Tokita M.D., Ph.D., is researcher in Department of Urology, Shiga University of Medical Science. Her research topics are neuroscience and andrology.

Hiroo Nakajima

Dr. Hiroo Nakajima Ph.D. is currently assistant professor of Institute for Radiation Sciences, Osaka University. His research topics are transgenerational effects due to biological effect of low dose-rate radiation and cesium-137 internal exposure.

Yuichiro Manabe

Dr. Yuichiro Manabe Ph.D. assistant professor, doctor of sciences(theoretical nuclear physics), is representative of interdisciplinary platform for biological effect of radiation, Collaborative Research Projects, Graduate School of Engineering, Osaka University. His research topics are simple mathematical model which give account to biological effects caused by radiation.

Takahiro Wada

Professor. Takahiro Wada Ph.D., is professor of Faculty of Engineering Science, Kansai University. His research interests lie in theoretical nuclear physics, especially the synthesis of superheavy elements, and in mathematical model analysis of the biological effects of radiation.

Masako Bando

Professor. Masako Bando Ph.D. is researcher in Research Center for Nuclear Physics, Osaka University and Yukawa Institute of Kyoto University. Her specialty is physics (elementary particle theory), and she extended her research to traffic flow theory, economic physics. She started to contract mathematical model of the biological effects of radiation after the Fukushima accident.