Variation of nitric oxide synthase activity in encothelial cells and effects of the variation on the cell injury
| Project/Area Number |
07672474
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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 |
応用薬理学・医療系薬学
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| Research Institution | Showa University |
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Principal Investigator |
MOMOSE Kazutaka Professor of Department of Pharmacology School of Pharamceutical Sciences, Showa University, 薬学部, 教授 (80004597)
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| Co-Investigator(Kenkyū-buntansha) |
SHIMUZU Shin'ichi Researcher, Department of Pharmacology School of Pharamceutical Sciences, Showa, 薬学部, 助手 (60196516)
石田 行知 三菱化学, 生命科学研究所, 主任研究員 (50092135)
ISHIDA Tomoyuki Chief Research of Life Science Institute Mitsubishi Chemicals Co.Ltd
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1996: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1995: ¥700,000 (Direct Cost: ¥700,000)
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| Keywords | disorder of vascular function / endothelial cells / nitric oxide / active oxygen / oxidative stress / 酸化的ストレス / 細胞障害 / ヒロドキシラジカル / グルタチオン / 一酸化窒素合成酵素 / 一酸化窒素測定法 / 細胞傷害 / 電極法 |
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| Research Abstract |
Nitric oxide synthase (NOS) generates NO from L-arginine in the presence of Ca^<2+>/calmodulin, NADPH,and tetrahydrobiopterin (BH_4) in vascular endothelial cells. However, NOS has been also shown to generate reactive oxygen species (ROS) at low concentrations of L-arginine or BH_4. We previously reported that N^G-nitro-L-arginine (L-NNA), an inhibitor of NOS,but not N^G-methyl-L-arginine (L-NMA), reduced H_2O_2-induced endothelial cell injury. L-NNA has been shown to block the substrate-independent generation of ROS,whereas L-NMA has not effect on this reaction. Therefore, we speclated that L-NNA blocked the substrate-independent generation of ROS by NOS during oxidative stress and consequently reduced H_2OS_2-induced endothelial cell injury. In the present study, L-NNA reduced not only H_2O_2-induced endothelial cell injury but also intracellular oxidative stress (glutathione depletion) -induced endothelial cell injury. On the other hand, L-NNA did not affect H_2O_2-induced or glutathione depletion-induced cell injury in RFL-6 cells which lack NOS.These results suggested the protective effect of L-NNA is likely to be related to NOS.Moreover, we fund that H_2O_2 treatment of endothelial cells increases intracellular Ca^<2+> before cell death, and stimulates NOS activity. These results strongly supporte that our hypothesis that L-NNA blocks the generation of ROS by NOS during oxidative stress and consequently reduces H_2O_2-induced endothelial cell injury. Moreover, in the present study, we developed a method of direct measurement of NO using NO-sensitive electrode. In the future, we will attempt to develop the new NO-sensitive electrode but ROS-insensitive and measure the NO release during oxydative stress.
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Report
(3 results)
Research Products
(7 results)
