Detection of Molecular Pathological Effects of Internal Exposure and Patho-Microdosimetric Analysis of the Surrounding Cells

2023 Fiscal Year Final Research Report

• Project/Area Number: 18K10027
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 58020:Hygiene and public health-related: including laboratory approach
• Research Institution: Nagasaki University
• Principal Investigator: SHICHIJO Kazuko 長崎大学, 原爆後障害医療研究所, 客員研究員 (90136656)
• Project Period (FY): 2018-04-01 – 2024-03-31
• Keywords: 内部被ばく / 原子爆弾 / 放射性微粒子 / DNA損傷 / 肺 / 小腸 / 幹細胞 / XAFS解析

Outline of Final Research Achievements

12 years after the Fukushima nuclear accident, radiation effects are of interest in the control of tumorigenesis and basic research is important. This study is aimed to detect the effects of residual radioactivity in the body on the human body as internal exposure by molecular pathology and to examine the relationship with microdosimetry of tissue cells. Rats were exposed to radioactive MnO2 by irradiation in the nuclear reactor of the National Nuclear Research Center of Kazakhstan. In the lungs exposed to an absorbed dose of 0.11 Gy with activated Mn-56 particles, severe pathology including hemorrhage, emphysema, atelectasis, and granuloma and abnormal deposition of elastin were observed from 6 hours to 180 days later, and Mn2+ coexisting with Fe elements was found in the lungs; in the small intestine at 1.48 Gy, inflammation, shortening, stem cell damage, and Mn2+ were identified, and along with the lungs, pathological changes not seen with external exposure doses.

Free Research Field

実験病理

Academic Significance and Societal Importance of the Research Achievements

原爆被ばく線量の評価には、一次放射線による外部被ばくと更に 留放射能微粒子による内部被ばくの影響を解明する必要がある。これは、原発事故での放射性微粒子被ばくの影響評価においても重要である。福島原発事故後、放射線の作用は腫瘍発生に関する研究の中で最も関心事となり基礎研究の重要性が増している。内部被ばくが局所的な高線量をもたらして細胞レベルで大きな影響を与えているのか。実験では細胞増殖能や出血などの病態とPatho-マイクロドジメトリーとしての検討が一致し、局所的高線量が大きな生体影響を与えた。内部被ばく線量とその病理学的意義を研究することで、人体残留放射能の生物学的影響が肺と腸管で明らかになる。