Establishment Of The Middle Cerebral Artery Occlusion Model And Study On Changes Of NGB, SOD And MDA In Rat Following Cerebral Ischemic-Reperfusion Injury

Part one: Establishment of the middle cerebralartery occlusion modelObjective: To establish a simple, reliable and minor trauma model of focal cerebral ischemia in Sprague-Dawley rats. Methods: The focal cerebral ischemia model in Sprague-Dawley rats were made by the modified suture -occuluded method of Zealonga and Koizum. Then the reliability of this model was evaluated with the examination of neurological method, TTC staining.Results: 2 hours after MCAO, rats showed neurologincal functional obstacle, TTC staining clearly indicated the brain infarct. Conclusion: The improved model is simple, reliable, minor trauma and stable. It is advisable to use this experimental animal model to study focal cerebral ischemia.Part two: Study on changes of NGB, SOD and MDA in rat following cerebral ischemic—reperfusion injuryObjective: To investigate the dynamic changes of neuroglobin expression in pallium and superoxide dismutase and malondialdehyde in serum in rats following ischemic—reperfusion injury. Methods: Sprague-Damley male rats were subjected to 90min of focal ischemia induced by middle cerebral artery occlusion with a filament insert, followed by 1h, 4h, 8h, 16h, 32h, 64h and 128h of reperfusion. Sham operated rats not subjected to MCAO served as controls. Immunohistochemical method was performed to observe the change ofneuroglobin staining in cerebral ischemic penumbra. The serum was taken after reperfusion in the all groups, respectively, for determination of SOD activities by xanthine oxidase method and MDA content by thibabituric acid method. Results: NGB protein was up-regulated from 1h to 32h after ischemic-reperfusion insult in cerebral ischemic penumbra, next was down-regulated. The activity of SOD decreased immediately after operation, came to the lowest point after 36h, then increased in the following time, whereas the leaves of MDA came to the highest point after 36h, then decreased. They have negative correlation. Conclusion: NGB may have important function in the adaptive protection process of ischemic brain damage. Serum levels of SOD and MDA maybe popular use as a new index on early diagnosis and treatment assessment in hypoxic-ischemic encephalopathy.