2000 Fiscal Year Final Research Report Summary
Radiation hormesis ; Induction of endogenous thiol containg autioxidants by low-dose radiation
| Project/Area Number |
11680556
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
環境影響評価(含放射線生物学)
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| Research Institution | Science University of Tokyo |
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Principal Investigator |
KOJIMA Shiji Science Univ.of Tokyo, Pharmacentical Sciences, Associate Prof., 薬学部, 助教授 (90119579)
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| Project Period (FY) |
1999 – 2000
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| Keywords | Radiation hormesis / Glutathione / Sigualling / Colcium Ion |
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| Research Abstract |
First, the mechanisms of the elevation of glutathione level induced in macrophage-like RAW 264.7 cells by low doses of γ-rays was examined. Doses between 25 and 100 cGy significantly increased the glutathione level at 4 hr post-irradiation. It was also shown that the elevation of glutathione level in cells irradiated with low doses of γ-rays followed the induction of mRNA coding for γ-GCS, a rate-limiting enzyme of the de novo glutathione synthesis pathway. Based on the inhibitory effects of various inhibitors of protein kinases on the induction of γ-GCS mRNA by low-dose γ-ray, it has been suggested that the tyrosine kinase, calcium channel, and protein kinase C activities play an essential role in the low-dose-radiation-induced elevation of cellular glutathione.
Then, involvement of glutathione in the appearance of radioresistance and the enhancement of immune function induced by low-dose radiation was examined. As a result, it has been found that the induction of endogenous glutathione in living cells soon afer low-dose γ-ray irradiation is at least partially responsible for the appearance of radioresistance to a subsequent lethal dose of radiation and of the enhancement of immune function.
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Research Products
(16 results)
