2005 Fiscal Year Final Research Report Summary
Researches on the regenerating thymus after irradiation-to find out the responsible factors which may regulate the thymic epithelial cell regeneration
| Project/Area Number |
16591208
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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 |
Radiation science
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| Research Institution | Yamaguchi University |
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Principal Investigator |
FUKUMOTO Tetsuo Yamaguchi University, Faculty of Medicine, Professor, 医学部, 教授 (00040171)
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| Co-Investigator(Kenkyū-buntansha) |
SAWADA Tomoo Yamaguchi University, Faculty of Medicine, Assistant Professor, 医学部, 講師 (90187295)
TOKUDA Nobuk Yamaguchi University, Faculty of Medicine, Assistant Professor, 医学部, 講師 (70227578)
ADACHI Yasuhiro Yamaguchi University, Faculty of Medicine, Research Associate, 医学部, 助手 (10346546)
EBE Kazuyu Yamaguchi University, Faculty of Medicine, Assistant Professor, 医学部附属病院, 講師 (90213579)
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| Project Period (FY) |
2004 – 2005
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| Keywords | rat / thymus / irradiation / immunohistochemistry / thymic epithelial cell / cytokines / regeneration / p63 |
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| Research Abstract |
(1)Rats were irradiated and the thymus was examined morphologically. Comared to the 6 Gy irradiation, in the case of 8 Gy irradiation, the recovery of thymocytes was slower. although the findings in the thymus at the time of recovery from both 6 Gy and 8 Gy irradiations were similar.
(2)P63 molecule can be detected specifically in the immatrure epithelial cells in the rat epidermis. In the normal rat thymus, p63 molecules were detected sporadically, especially in the region of the subcapsular area. After irradiation, the relative number of p63 positive thymic epithelial cells increased in number. These suggest that after irradiation, in the thymus, not only the thymocyte but also the thymic epithelial cell were destroyed and in addition to the abrupt thymocyte regeneration, even regeneration of the thymic epithelial cells may take place. Following the different doses of irradiation, the degree of the damages on the thymic epithelial cells may be different and subsequently, after irradiation and on the process of regeneration, some irreversible changes may be induced on the thymic epithelial cells and resulted in only 65% of recovery in the thymus weight in the 8Gy irradiation.
(3)The cytokine message expressions were different between 6 Gy and 8 Gy-irradiated thymi. Particularly, the message levels for Il-6 were significantly low in the 8Gy irradiated thymus compared to those in 6 Gy irradiated thymus., when the messages were measured at the recovered time from the irradiation.
(4)The primary cultured thymic epithelial cells, which were irradiated at the irradiation doses of either 6 Gy or 8 Gy were used for induction of thymocyte differentiation in vitro. However, from our experioments statistically significant differences were not observed between 6 Gy and 8 Gy irradiation.
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