1994 Fiscal Year Final Research Report Summary
Estimation of oxygen delivery during cerebral ischemia and the consequent tissue damage.
| Project/Area Number |
05454421
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Anesthesiology/Resuscitation studies
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
ARAI Toshiyuki Kyoto University, Medicine, Associated Professor, 医学部, 助教授 (80175950)
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| Co-Investigator(Kenkyū-buntansha) |
MORI Kenjiro Kyoto University, Medicine, Professor, 医学部, 教授 (20025620)
NAKAO Shinichi Kyoto University, Medicine, assistant, 医学部, 助手 (10207714)
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| Project Period (FY) |
1993 – 1994
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| Keywords | cerebral ischemia / gerbils / NIR / MRI / MAP2 / oxygen free radicals / EPR / neopterin |
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| Research Abstract |
Oxygen delivery during cerebral ischemia was estimated using a near infrared laser spectrophotometry (NIR) and magnetic resonace imaging (MRI). The consequent tissue damage and its attenuation by drugs were examined using an immunohistochemical technique (MAP2 stain).
1. Oxygen delivery during cerebral ischemia : Cerebral ischemia was produced in a gerbil by occluding the bilateral common carotid arteries for 8 min. Oxygen delivery to brain reduced dramatically during ischemia, which was confirmed by NIR and MRI.
2. Tissue damage following cerebral ischemia : Seven days after the above-mentioned ischemic challenge, the gerbils were perfused by a fixative. The brain was removed and its slices were stained by MAP2. Ischemic legions were clealy detected in the CA1 region of both hippocampi.
3. Effects of neopterin (NP) on ischemic neuronal damages : The preischemic administration of NP (3mg/kg) attenuated ischemic neuronal damages in gerbils. NP may prevent the ischemic injury by detoxicating oxygen free radicals generated during ischemia-reperfusion.
4. Mechanism of oxygen free radical scavenging by neopterin (NP) : In the hypoxanthine-xanthine oxidase and the neutrophil-phorbol myristate acetate reaction systems, the oxygen free radical scavenging activity of NP was examined using an electron paramagnetic resonance (EPR). The results indicated that NPH-4 (the reduced form of NP) detoxicated the generated oxygen free radicals in the both systems, while NP itself suppressed the oxygen free radical generation.
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