| Project/Area Number |
09670667
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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 |
Neurology
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| Research Institution | Keio University |
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Principal Investigator |
AMANO Takahiro (1998) Keio University, Department of Neurology, Assistant Professor, 医学部, 専任講師 (90118901)
白井 俊孝 (1997) 慶應義塾大学, 医学部, 助手 (80196592)
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| Co-Investigator(Kenkyū-buntansha) |
MURAMATSU Kazuhiro Keio University, Department of Neurology, Instructor, 医学部, 助手 (20230005)
OBARA Katsuyuki Keio University, Department of Neurology, Instructor, 医学部, 助手 (40169363)
SHIRAI Toshitaka Keio University, Department of Neurology, Instructor, 医学部, 助手 (80196592)
天野 隆弘 慶應義塾大学, 医学部, 専任講師 (90118901)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Cerebral Blood Flow / autoregulation / Nitric Oxide / L-NIO / K+ channal blocker / TEA / 脳循環 / eNOS / 脳循環調節機序 / Nitric oxide(NO) / 脳循環自動調節 / 脳血管口径 / 脳血液含量(CBV) / 脳軟膜血管 / NOセンサー / Vasomotor Index |
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| Research Abstract |
Involvement of the nitric oxide (NO) system alone may not explain the entire mechanism of cerebral autoregulatory responses. An additional mechanism, such as potassium channels, may be involved in these processes. The aim of the present investigation is to examine the possible additional role of potassium channel conductance in the mechanism of the cerebrovascular autoregulatory responses during changes in systemic blood pressure. Twenty three cats were anesthetized and mechanically ventilated. A cranial window method was used to record changes in pial vessel diameters via a video camera system. Cerebrovascular autoregulatory responses of pial vessel were tested by hemorrhage and reinfusion. The extent of the cerebrovascular autoregulatory responses were evaluated by calculating Vasomotor Index (VMI). NG-iminoethyl-L-omithine (L-NIO) was utilized as a relatively specific endothelial NO inhibitor, and tetraethylammonium (TEA) was topically applied as nonspecific blockers of potassium channels. Animals were divided into two groups ; Group I (L-NIO group ; n =13 L-NIO (30 mg/kg) was administered intralingually.) Group 2 (TEA group ; n =1 QTEA (100 mM) superfusion was followed 30 minutes after the iniitiation of intralingual L-NL administrations.). Intralingual L-NIO (30 mg/kg) administration lowered VMI significantly. No statistical significance were obtained between L-NIO group and TEA group. There are no synergistic effects between NO and TEA-sensitive pathways at this concentration of TEA.
A endothelial NO pathway may play a role in the cerebrovascular autoregulatory responses. Additional TEA, however, fail to modulate these responses. TEA-sensitive-mechanism might not be involved in these process at least at this concentration of TEA.
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