| Project/Area Number |
10555292
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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 | 展開研究 |
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| Research Field |
生物・生体工学
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| Research Institution | Kawasaki College of Allied Health Professions |
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Principal Investigator |
MOCHIZUKI Seiichi Kawasaki College of Allied Health Professions, Medical Engineering, Associate Professor, 臨床工学科, 助教授 (60259596)
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| Co-Investigator(Kenkyū-buntansha) |
GOTO Masami Kawasaki College of Allied Health Professions, Medical Engineering, Professor, 臨床工学科, 教授 (50148699)
OGASAWARA Yasuo Kawasaki Medical School, Medical Engineering, Associate Professor, 医学部, 助教授 (10152365)
KAJIYA Fumihiko Okayama University Medical School, Physiology II, Professor, 医学部, 教授 (70029114)
HIRAMATSU Osamu Kawasaki College of Allied Health Professions, Medical Engineering, assistant Professor, 臨床工学科, 講師 (50208849)
MATSUMOTO Takeshi Kawasaki College of Allied Health Professions, Medical Engineering, Associate Professor, 臨床工学科, 助教授 (30249560)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥9,900,000 (Direct Cost: ¥9,900,000)
Fiscal Year 2000: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1999: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1998: ¥6,100,000 (Direct Cost: ¥6,100,000)
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| Keywords | nitric oxide (NO) / canine femoral artery / NO sensor / tetrahydrobiopterin / superoxide / fluorescent indicator / coronary circulation control / systemic NO production rate / 硝酸イオン / ラット摘出心 / 潅流量 / 蛍光計測 / NADH / ラット腸間膜小動脈 / ニトログリセリン / 微小電極 |
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| Research Abstract |
1. Isolated canine femoral artery : An NO microelectrode (100 μm in diameter) was inserted into the vascular media where flow-induced endothelium-derived NO production was measured NO production was changed with a time constant of about 24 sec, and a linear relation was observed between perfusion rate and produced NO.
Flow-induced NO production was attenuated by exogenous NO (SNAP), and this suppressive effect was disappeared by perfusing BH_4, a cofactor of NO synthase (NOS). Simultaneous perfusion of SNAP and Tiron, superoxide scavenger did not affect endogenous NO production. Collectively, exogenous NO perfusion induces a decrease in intracellular BH_4 level, leading to superoxide release from NOS.Reaction between NO and superoxide is known to produce peroxynitrite, which attenuates NOS activity.
2. Isolated rat mesenteric small artery : Intravascular-wall NO was visualized by an NO fluorescent indicator (DAF-2DA), and uniformly distributed NO fluorescence was observed during nitroglycerin (NTG) perfusion. In addition, it was found that thiol-containing molecules are involved in the NTG-derived NO production mechanism.
3. Isolated perfused rat heart : When perfusion pressure was decreased from 100 to 50 cmH_2O, coronary perfusion rate decreased by half ; however, NO production was nearly doubled Despite decreased coronary perfusion rate by decreased perfusion pressure, NO production was increased in association with regulation mechanism of oxygen supply.
4. Estimation method of systemic NO production rate : Plasma nitrate level in blood samples collected after simple 14-hr fasting was measured, and systemic NO production rate was estimated to be about 600 nmol/min by a single-compartment analysis. Compared with other previous estimation methods such as urinary nitrate and RI, estimated values were comparable.
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