| Project/Area Number |
09671442
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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 | Nara Medical University |
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Principal Investigator |
NAKASE Hiroyuki Nara Medical University, Assistant Professor, 医学部, 講師 (10217739)
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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 |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1998: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1997: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | rat / penumbra / cerebral blood flow / oxygen saturation |
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| Research Abstract |
Backbrouns and purpose : The concept of the ischemic penumbra is a salvage area and considered to silent for the electrophysiological activity of the neuron. We studied the validity of a new rat global ischemic model using hypobaric hypotension technique to establish the penumbra-like tissuse and whether chemical preconditioning with 3 -nitropropionate (3 -NPA) affects the iscbemic penumbra.
Methods : In Wistar rats (n=18), the cerebral blood flow (CBF) was reduced using the global ischemia by bilateral carotid artery occlusion coupled with hypobaric hypotension until the electrophysiological activity in the frontoparietal cortex became silent under an electroencephalic graph (EEG) monitoring. The interval between the flat EEG and ischemic depolarization was measured. The regional CBF (rCBF) and saturation of oxyhemoglobin (%HbSO2) were also measured using laser-Doppler scanning technique and the Erlangen microlightguide spectrophotometer (EMPHO). Eighteen animals were dented to two group ; eight animals (group A) were non-treated and ten animals (group B) were treated with intraperitoneal injection of 20 mg/kg 3-NPA 3 hours prior to global ischemia.
Results : Initial mean arterial blood pressure, rCBF, and %HbSO2 in both group were not different statistically. The rCBF and %HbO2 at the EEG flattning were 11.0*3.9 LD-units and 29.8*2.4% in group A, 8.0* 2.2 LD-units and 27.8*2.9% in group B.At the state of the ischemic deporalization, the rCBF and %HbO2 were 5.2*0.6 LD-units and 27.0*31% in group A, 5.4*0.6 LD-units and 24.6*3.6% in group B.The duration between EEG flatning and ischemic deporalization (penumbra-like tissue) were 89.4*20.2 seconds in group A and 158.0*66.8 seconds in group B (p(]SY.di-substituted right.[)O.05).
Conclusions : Penumbra-like tissue could he reproduced using our new rat global ischemic model and chemical preconditioning with 3-NPA prolonged the duration of this penumbra-like tissue.
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