| Project/Area Number |
16590255
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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 |
Pathological medical chemistry
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| Research Institution | Fujita Health University |
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Principal Investigator |
SUMI-ICHINOSE Chiho Fujita Health University, School of Medicine, Associate Professor, 医学部, 助教授 (10247653)
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| Co-Investigator(Kenkyū-buntansha) |
NOMURA Takahide Fujita Health University, School of Medicine, Professor, 医学部, 教授 (20156227)
SHIRAISHI Hiroaki Fujita Health University, School of Medicine, Assistant, 医学部, 助手 (80319285)
IKEMOTO Kazuhisa Fujita Health University, School of Medicine, Assistant, 医学部, 助手 (40351019)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2005: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2004: ¥2,900,000 (Direct Cost: ¥2,900,000)
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| Keywords | tetrahydrobiopterin / dopa-responsive dystonia / 6-pyruvoyltetrahydropterin synthase / striatum / dopaminergic neuron / tyrosine hydroxylase / knockout mice / transgenic mice / 6-ピルボイルテトラヒドロプテリン合成酵素 / 6-ピルポイルテトラヒドロプテリン合成酸素 |
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| Research Abstract |
Tetrahydrobiopterin (BH4) is an essential cofactor for phenylalanine hydroxylase, tyrosine hydroxylase (TH), tryptophan hydroxylase (TPH), and all types of nitric oxide synthase. Previously, we established BH4-defficient mice (Pts^<-/->) by disruption of the gene encoding 6-pyruvoyltetrahydropterin synthase (PTS), which catalyzes the second step of BH4 biosynthesis. For Pts^<-/-> mice died shortly after birth, we rescued those by transgenic introduction of human PTS cDNA under the control of 5.8 kb human dopamine β-hydroxyklase 5' promoter (DPS). We performed biochemical analysis using 2-7 months old male DPS-rescued mice (Pts^<-/->,DPS). PTS activity in the liver of DPS-rescued mice was 2.1 % of that of wild type (Pts^<+/+>) ones. Plasma phenylalanine concentration of DPS-rescued mice was 37 times higher than that of wild type, and reduced to 15% 1 hour after intraperitoneal injection of 20g/kg BH4. It was confirmed that human PTS efficiently expressed in the adrenal medulla and noradrenergic cells including locus ceruleus by immunohistochemistory using anti-human PTS antibody, and also by double-immunofluorescence staining using anti-human PTS antibody with anti-bovine TH antibody. However, human PTS expressed in a part of the dopaminergic cells in the substantia nigra and ventral tegmental area. Content of biopterin and dopamine in the midbrain of DPS-rescued mice were 84% and 52% of those of wild type, respectively. On the other hand, content of biopterin and dopamine in the striatum of DPS-rescued mice were 21% of those of wild type. The nucleus accumbens and medial part of the striatum of DPS-rescued mice were immunoreactive to anti-TH antibody as strongly as those of wild type. On the contrary, lateral region of the striatum of DPS-rescued mice was far weakly stained by anti-TH antibody. Thus we concluded that TH protein in dopaminergic nerve terminals projecting to the lateral region of striatum is the most sensitive to BH4-insyfficiency.
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