| Project/Area Number |
07458200
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nerve anatomy/Neuropathology
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| Research Institution | OSAKA CITY UNIVERSITY |
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Principal Investigator |
TAKAGI Hiroshi OSAKA CITY UNIV.MED.SCH., ANATOMY,PROFESSOR, 医学部, 教授 (30163174)
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| Co-Investigator(Kenkyū-buntansha) |
YONEDA Takunari OSAKA CITY UNIV.MED.SCH., ANATOMY,INSTRUCTOR, 医学部, 助手 (70271179)
MAEDA Mituyo OSAKA CITY UNIV.MED.SCH., ANATOMY,ASSIST.PROF., 医学部, 講師 (40122080)
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| Project Period (FY) |
1995 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥6,800,000 (Direct Cost: ¥6,800,000)
Fiscal Year 1997: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1996: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1995: ¥4,200,000 (Direct Cost: ¥4,200,000)
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| Keywords | NO / SOD / Hippocampus / striatum / somatostatin / スーパーオキシド / インターロイキン-1 / インターロイキン-1受容体 / ICE / 脳虚血 / ラジカル / 神経伝達機序 / 虚血 |
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| Research Abstract |
Strong immunoreactivity for manganese superoxide dismutase (Mn-SOD)is seen in neostriatal somatostatin neurons, these being identical to nitric oxide synthase (NOS) neurons. These neostriatal neurons are selectively resistant to various kinds of neurotoxic insults, such as ischemia, NMDA-mediated neurotoxicity, and Huntington's disease. Although the reason for their resistance is not known, it has been suggested that SOD may prevent the formation of the peroxynitrite anion and may thus reduce cell death among NOS neurons in the neostriatum. It remained unclear whether such neurons in the hippocampus are resistant to neurotoxic insults in a manner similar to that shown in the neostriatum. The present study demonstrated, by using a double immunostaining method and a enzyme histochemical staining method, that the NOS cell population in the hippocampus is almost always different from that of Mn-SOD neurons ; virtually all of the latter neurons had no or weak Mn-SOD immunoreactivity in all subfields, although Mn-SOD-and NOS-immunoreactive neurons showed a similar distribution. Therefore, it is unlikely that Mn-SOD participates in the inhibition of the preoxynitrite pathway in hippocampal NOS neurons. However, it can not be ruled out that such NO-SOD interaction may occur in CA3 pyramidal cells being resistant to ischemic insults, since they show strong immunoreactivity for Mn-SOD.As pyramidal cells do not exhibit NOS-immunoreactivity, it is possible that thay may receive a considerale amount of NO from neighboring cells or from neurites containing NOS.In contrast, Mn-SOD is weakly immunostained in CA1 pyramidal cells, which cells are very vulnerable to ischemic insults. Differences in the intracellular amounts of Mn-SOD may be, in part responsible for the differences in the degree of neurotoxicity between CA1 and CA3 pyramidal cells.
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