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1990 Fiscal Year Final Research Report Summary

Mechanism of the Expression of Radio-Adaptive Response

Research Project

Project/Area Number 01580210
Research Category

Grant-in-Aid for General Scientific Research (C)

Allocation TypeSingle-year Grants
Research Field 放射線5生物学
Research InstitutionKyoto University

Principal Investigator

IKUSHIMA Takaji  Res. Reactor Inst., Kyoto Univ. Instructor, 原子炉実験所, 助手 (80027458)

Project Period (FY) 1989 – 1990
KeywordsLow-level radiation / Adaptive response / Chromosomal aberrations / Radiation tolerance / DNA repair / Mechanism of gene expression / Radiation hormesis / SCE
Research Abstract

An adaptive response to ionizing radiation was found in cultured mammalian cells, as a phenomenon of a suppressed induction of chromosomal aberrations (micronuclei, SCEs) by challenging doses when cells were conditioned by very low doses. The term, 'radio-adaptive response' (RAR) was proposed for the novel chromosomal response (Mutation Res. 227, 241, 1989). The important characteristics that have emerged in cultured Chinese hamster cells are : 1. Very low doses of beta-rays from tritiated water as well as from tritiated thymidine can induce the RAR. 2. The RAR is dependent on the total dose of the challenging (pretreatment) and the rate at which the doses are given. The RAR can be induced only by a narrow window of challenging doses (cGy level). 3. Gamma-rays can act as ^3 H beta-rays, but thermal neutrons, a high LET radiation, is not effective for induction of the RAR. 4. A 4-h interval is enough for the full expression of the RAR, which decays with the progression of cell proliferation. 5. The RAR is suppressed by an inhibitor of poly (ADP-ribose) polymerase. 6. The RAR can affect clastogenic lesions induced by UV-B, mitomycin C and thermal neutrons (weak), but not by EMS and cisplatin. 7. The RAR is inhibited by cycloheximide, an inhibitor of protein synthesis. 8. Several proteins are synthesized after irradiation with low doses of gamma-rays which can induce the RAR, concurrently with the expression of the RAR. This was revealed by means of 2-D polyacrylamide gel electrophoresis and fluorography. These characteristics suggest that the RAR is an induced chromosmal DNA repair which occurs under a restricted condition, and that the low-dose induced expression of 'RAR genes' is involved in the process of the RAR.

  • Research Products

    (15 results)

All Other

All Publications (15 results)

  • [Publications] T.Ikushima: "Radioーadaptive response:Characterization of a radiation in cultured Chinese hamster cells cytogenetic repair induced by lowーlevel ionizing" Mutation Research. 227. 241-246 (1989)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Ikushima: "SCE enigma:Methodology,mechanism and meaning of sister chromatid exchange(review)" Annu.Rep.Res.Reactor Inst.,Kyoto Univ.22. 57-77 (1989)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Ikushima: "Radioーadaptive response:A novel chromosomal response in Chinese hamster cells in vitro" Choromosomal Aberrations:Basic and Applied Aspects (eds.G.Obe and A.T.Natarajan)SpringerーVerlag. 151-162 (1990)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Ikushima: "Bimodal induction of sisterーchromatid exchanges by luminol,an inhibitor of poly(ADPーribose)synthetase,during the Sーphase of the cell cycle" Chromosoma. 99. 360-364 (1990)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Ikushima: "Visualization of DNA damage in individual cells" Annu.Rep.Res.Reactor Inst.,Kyoto Univ.23. 85-90 (1990)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 生島 隆治: "低レベル放射線に対する適応応答:放射線ホルミシスの基礎機構?" 医学のあゆみ. 148. 646 (1989)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 生島 隆治: "放射線適応応答:低線量放射線による遺伝子発現の誘導" 京都大学原子炉実験所第25回学術講演会報文集. 95-100 (1991)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 生島 隆治: "放射線適応応答の機構とその意義:低線量放射線による遺伝子発現の誘導" 医学のあゆみ. 157. (1991)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Ikushima, T.: "Radio-adaptive response : Characterization of a cytogenetic repair induced by low-level ionizing radiation in cultured Chinese hamster cells" Mutation Research. 227. 241-246 (1989)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Ikushima, T.: "SCE enigma : Methodology, mechanism and meaning of sister chromatid exchange (review)" Annu. Rep. Res. Reactor Inst., Kyoto Uni.v. 22. 57-77 (1989)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Ikushima, T.: "Radio-adaptive response : A novel chromosomal response in Chinese hamster cells in vitro" Chromosomal Aberrations : Basic and Abblied Aspects (eds. G. Obe & A. T. Natarajan) Springer-Verlag. 151-162 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Ikushima, T.: "Bimodal induction of sister-chromatid exchanges by luminol, an inhibitor of poly (ADP-ribose) synthetase, during the S-phase of the cell cycle" Chromosoma. 99. 360-364 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Ikushima, T.: "Visualization of DNA damage in individual cells" Annu. Rep. Res. Reactor Inst., Kyoto Uni. v. 23. 85-90 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Ikushima, T.: "The adaptive response to very low doses of radiation : Basic mechanism of radiation hormesis? (in Japanese)" Igaku-no-ayumi. 148. 646 (1989)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Ikushima, T.: "Mechanism of radio-adaptive response : An induction of gene expression by low-dose radiation (in Japanese)" Igaku-no-ayumi. 157. (1991)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 1993-08-12  

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