| Project/Area Number |
06671385
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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 |
Cerebral neurosurgery
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| Research Institution | Mie University |
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Principal Investigator |
KANAMARU Kenji University Hospital, Mie University Lecturer, 医学部・付属病院, 講師 (70185908)
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| Co-Investigator(Kenkyū-buntansha) |
WAGA Shiro Faculty of Medicine, Mie University Professor, 医学部, 教授 (50026861)
久我 純弘 三重大学, 医学部・附属病院, 助手 (70221926)
村尾 健一 三重大学, 医学部, 助手 (60252368)
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| Project Period (FY) |
1994 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1996: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1995: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1994: ¥900,000 (Direct Cost: ¥900,000)
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| Keywords | Nitroglycerin / Nitric Oxide (NO) / Subarachnoid Homorrhage / Vasospasm / cGMP / Hyperpolarization / Protein S / AntithrombinIII / 脂質過酸化反応 / 脳血管攣縮 / 細胞膜過分極 / パッチクランプ / 正中縫線核細胞 / 網膜神経節細胞 / whole-cell curent clamp / whole-cell voltage clamp / potassium current / calcium carrent / tetraethylammonium / 4-aminopyridine / 細胞膜電位 / Patch-electrode voltage-clanp / Whde-cellmerbrane current / 平滑筋細胞 / 神経細胞 |
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| Research Abstract |
Nitroglycerin, as well as nitric oxied, causes hyperpolarization and cGMP elevation in vascular smooth muscle cells. It is unknown whether nitroglycerin ameliorates vasospasm by an increase in cGMP levels after sudarachnoid hemorrhage (SAH). The purpose of the first study was to measure the levels of cGMP and cAMP in the cerebral arteries and parietal cerebral cortices in a primate model and to determine the effect of nitroglycerin on vasospasm after SAH.Chronic vasospasm was induced by clot placement around the right middle cerebral artery (MCA). Seven days after the surgery, angiography was repeated and either nitroglycerin or saline was administered intrevenously. A significant vasospasm occurredin the cerebral arteries on both sides, more prominently on the right side. Concomittantly, rCBF on the right side was significantly decreased. In the right MCA,cGMP levels were significantly lower than in the normal MCA.After the administration of nitroglycerin for 3 hours, the cerebral vessels were significantly dilated on both sides, and rCBF was singnificantly increased on the right side but not on the left side. Although depressed cGMP levels in the right MCA were not recovered by nitroglycerin, a significant increase in cGMP levels was observed in the basilar artery. In both parietal cortices, cGMP levels were significantly decreased after SAH and unchanged after nitroglycerin treatment. There were no significant changer in cAMP levels in SAH and after nitroglycerin treatment. In conclusion, the vasodilator effect of nitroglycerin in spastic MCA may not be mediated by an increase in cGMP levels, suggesting an involvement of hyperpolarization of the smooth muscle cells.
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