Protective Effects Of EGB 761 For Cerebral Ischemia-reperfusion Injuries In Rats

Objective: The study was carried out to prove protective effects of Ginkgo biloba extract (EGB )761 for cerebral Ischemia-reperfusion injuries (CIRI) and to find out the effective mechanism by testing changes of the content of nitrogen monoxide ( NO ), nitricoxide synthase ( NOS ), superoxide dismutase (SOD), malondialdehyde (MDA) in the brain tissues of rats with CIRI and observing changes of praxiology , morphology and pathology in the brain cell of rats with CIRI.Method: All focal CIRI models in rats were made by line bolt method. The rats were divided at random into two groups: Biochemical index group (group one) and praxiological and pathological detecting group (group two). The rats in group one were divided at random into four subgroup, each with 8. Pse-operation subgroup (operated but middle cerebral artery were not blocked); Non-treatment model subgroup (ischemia 3h,reperfusion 2h); low dose model subgroup (EGB761 5mg/kg, ischemia 3h, reperfusion 2h); High dose model subgroup (EGB761 15mg/kg, ischemia 3h, reperfusion 2h) .The subjects were killed 2h after reperfusion and detected biochemical index. The rats in group two were divided at random into three subgroup,each with 8. Pse-operation subgroup,non-treatment model subgroup (ischemia3hreperfusion24h ) and high dose model subgroup (EGB761 15mg/kg , ischemia3h, reperfusion24h ); The subjects were suffered the grade of nerves function injuries after 24h ischemia-reperfusion. The subjects were killed after grade and performed pathological examines.Result: 1. In group one, compared with non-treatment model subgroup, there were obvious reduce of the content of NO, NOS, MDA and marked increase of SOD in the brain tissues of rats in low dose model subgroup (P<0.01). 2. It is significant difference in the grade of nerves function injuries between non-treatment model subgroup and high dose model subgroup in group two (P <0.01) . This result indicated that nerves function injuries areslight in high dose model subgroup. Under the light microscope, there were clear infarcted zone and disappeared cortical cell structures, arrange in confusedness, obvious edema of cell and interstitial and shrunken and hyperchromatic nucleus in non-treatment model subgroup; In high dose model subgroup the most neuron structure is integrity, normomorph and slight cell and interstitial edema; No infracted zone in pse-opearation.Conclusion: 1.EGB761 have protective effects for CIRI, especially in high dose group. 2. EGB 761 protects the brain against ischaemia-reperfusion injury via its free radical scavenging and anti-lipoperoxidative properties and releasing injury of nitrogen monoxide in later stage of ischemia.