| Project/Area Number |
08680587
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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 | University of Occupational and Environmental Health |
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Principal Investigator |
OOTSUYAMA Akira University of Occupational and Environmental Health, School of Medicine, Associate Professor, 医学部, 助教授 (10194218)
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| Co-Investigator(Kenkyū-buntansha) |
NOMOTO Satoshi University of Occupational and Environmental Health, School of Medicine, Researc, 医学部, 助手 (90258608)
NORIMURA Toshiyuki University of Occupational and Environmental Health, School of Medicine, Profess, 医学部, 教授 (20039530)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1997: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1996: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | lpr mice / gld mice / gamma rays / spleen / thymus / T cell / Fas / Apoptosis / 1prマウス / FAS |
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| Research Abstract |
In Makinodan's study (Makinodan, et al., 1990) , gamma rays of 0.04Gy or 0.1Gy were irradiated three times a week (total 20 times) in immune deficiency lpr mice. They reported that after the erradiation, the number of accumulated double-negative (CD4-/CD8-) T cells in the spleen was reduced.
We analyzed whether there was a relationship between radiation sensitivity and apoptosis of the double-negative T cells accumulated in the spleen and thymus of the lpr and gld mice.
The reduction of double-negative subpopulation of the spleen was statistically significant in MRL/Mpj-lpr/lpr mice with acute 1Gy gamma irradiation. In the protoractive irradiation group (total dose 0.98Gy) , statistical significance was not seen but the proportion of T cell subpopulations was improved.
As any typical symptoms by immune-deficiency were not found in the study, using the C57BL/6J-lpr/lpr mice which were used by Makinodan, we could not observe the effects of irradiation on the mice.
In the study with the MRN/MpTn-gld/gld mice, a reduction of double-negative subpopulation, and an increase of single-positive (CD4+/CD8-) subpopulation was observed in the spleen of the irradiation group. A reduction of the double-negative subpopulation and an increase of double-positive (CD4+/CD8+) subpopulation was observed in the thymus, but there was not statistical significance in ether result.
Background and immune-deficiency conditions of the lpr and gld mice used for the experiments were different from Makinodan's. But, we found that the proportion of T cell subpopulations tended to improve. We guessed that the apoptosis occurred in the double-negative subpopulation with low dose radiation. We knew that the process of apoptosis-induced radiation did not need the Fas-FasL function.
Retardation of disease progression by immune-deficiency of these mice might be possible with low dose radiation.
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