| Project/Area Number |
15390545
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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 | 一般 |
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| Research Field |
Emergency medicine
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| Research Institution | Osaka University |
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Principal Investigator |
SHIOZAKI Tadahiko Osaka University, Graduate School of Medicine, Assistant, 医学系研究科, 助手 (60278687)
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| Co-Investigator(Kenkyū-buntansha) |
SUGIMOTO Hisashi Osaka University, Graduate School of Medicine, Professor, 医学系研究科, 教授 (90127241)
TANAKA Hiroshi Osaka University, Graduate School of Medicine, Assistant Professor, 医学系研究科, 助教授 (90252676)
OGURA Hiroshi Osaka University, Graduate School of Medicine, Assistant, 医学系研究科, 助手 (70301265)
TASAKI Osamu Osaka University, Graduate School of Medicine, Assistant, 医学系研究科, 助手 (90346221)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥12,500,000 (Direct Cost: ¥12,500,000)
Fiscal Year 2005: ¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2004: ¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2003: ¥4,900,000 (Direct Cost: ¥4,900,000)
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| Keywords | Prolonged ischemia / Brain temperature / Cerebral blood flow / Somatosensory evoked potential / Ischemic reperfusion / 脳血流量 / 脳温 / 神経学的予後 |
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| Research Abstract |
In clinical situation, it takes rather long time to recover the cerebral reperfusion after stroke or cardiac arrest. We, therefore, aimed to identify differences in the postischemic recovery of physiological parameters between short and prolonged brain ischemia.
Eighteen Mongolian gerbils were assigned to one of three groups: 5-minute (G5), 15-minute (G15) and 30-minute (G30) ischemia. With the use of our original microspectroscopy system, global ischemic reperfusion was performed. We measured changes in regional cerebral blood flow (r-CBF), microvessel diameter, and brain temperature (BrT) simultaneously. We also monitered somatosensory evoked potentials (SEPs) to evaluate electrophysiological response.
Both G5 and G 15 showed concurrent recovery of r-CBF and BrT with hyperemia and hyperthermia, respectively, 10-15 minutes after reperfusion. The increase in BrT was < 1 ℃ and recovered to baseline within 60 minutes after reperfusion. In G30, recovery of r-CBF was significantly delayed relative to that of BrT. The increase in BrT was > 2 ℃, peaking approximately 15 minutes after reperfusion, and then remaining > 1 ℃ increased over 120 minutes. SEPs in G5 and G15 showed concomitant recovery with that of r-CBF, whereas SEP recovery in G30 was delayed relative to that of r-CBF, eventually disappearing. All except one of the G30 gerbils died within 24 hours, but all in G5 and G15 survived.
These results suggest that mismatch recovery of r-CBF and BrT after prolonged ischemia initiates metabolic derangement in brain tissue, leading to the electrochemical dysfunction and mortality afterward.
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