The biological effects of long-term radiation exposure especially in the low dose and low dose-rate areas have become a social concern after the accident of Fukushima Dai-ichi nuclear power plant. We focuses on the health impact of a non-human primate Japanese macaques which exposed to radiation in the ex-evacuation zone. We established the method of dose evaluation to optimize to Japanese macaque and evaluated radiation dose of individuals1, 2). We also demonstrates slight increase of oxidative stress in plasma and slight decrease of hematopoietic function in bone marrow which depends on internal dose-rate3, 4).
In addition to the soluble form, it has been confirmed that radiocesium was released into the environment as the form of insoluble microparticle by the accident of Fukushima Dai-ichi nuclear power plant. It is expected that inhalation of small-sized particles will deeply reach inside the body and cause long-term exposure. Cs-bearing microparticle (CsMP) which isolated from the soil in the ex-evacuation zone were co-cultured with normal human cells and we are looking for the effects by local exposure.
Our group has established normal human cells that have acquired resistance to lethal fractionated radiation exposure. We are currently elucidating the molecular mechanism of this resistant phenotype. We have also confirmed that the acquired resistant cells also demonstrated the resistance to the lethal tritium treatment. Elucidation of the molecular mechanism will provide basic knowledge for the development of radioprotective agents to apply to emergency exposure.
Suzuki M, Suzuki H, Ishiguro H, Saito Y, Watanabe S, Kozutsumi T, Sochi Y, Nishi K, Urushihara Y, Kino Y, Numabe T, Sekine T, Chida K, Fukumoto M. (2019) Correlation of Radiocesium Activity between Muscle and Peripheral Blood of Live Cattle Depending on Presence or Absence of Radiocontamination in Feed. Radiation Research, in press, doi: 10.1667/RR15418.1.
Urushihara Y, Suzuki T, Shimizu Y, Ohtaki M, Kuwahara Y, Suzuki M, Uno T, Fujita S, Saito A, Yamashiro H, Kino Y, Sekine T, Shinoda H, Fukumoto M. (2018) Haematological analysis of Japanese macaques (Macaca fuscata) in the area affected by the Fukushima Daiichi Nuclear Power Plant accident. Scientific Reports, 13;8(1):16748. doi: 10.1038/s41598-018-35104-0.
Nakamura AJ, Suzuki M, Redon CE, Kuwahara Y, Yamashiro H, Abe Y, Takahashi S, Fukuda T, Isogai E, Bonner WM, Fukumoto M. (2017) The Causal Relationship between DNA Damage Induction in Bovine Lymphocytes and the Fukushima Nuclear Power Plant Accident. Radiation Research, 187(5):630-636. doi: 10.1667/RR14630.1.
Suzuki M, Suzuki K, Kodama S, Yamashita S, Watanabe M. (2012) Persistent amplification of DNA damage signal involved in replicative senescence of normal human diploid fibroblasts. Oxidative Medicine and Cellular Longevity, 2012:310534. doi: 10.1155/2012/310534.
Suzuki M, Yamauchi M, Oka Y, Suzuki K, Yamashita S. (2012) Live-cell imaging visualizes frequent mitotic skipping during senescence-like growth arrest in mammary carcinoma cells exposed to ionizing radiation. International Journal of Radiation Oncology, Biology and Physics. 83(2):e241-50. doi: 10.1016/j.ijrobp.2011.12.003.