The Pretreating Mechanism Of Edaravone On Focal Cerebral Ischemiai Injury In Rat Brain

Objective:An embolus was placed at the origin of the middle cerebral artery by injection of an autologous single,blood clot via an intraluminal catheter placed in the intracranial segment of internal carotid artery.To investigate the effectiveness of edaravone,a free radical scavenger, on the cerebral infarction volume,and neurological deficits after middle cerebral artery occlusion in rat brain.To explore the effectiveness of edaravone on the histopathology of focal cerebral ischemia with H.E staining method.To explore the effectiveness of edaravone on lysoph-osphatidic acid and platelet.Methods:Thirty Wistar rats were randomly divided into five groups(=6 each):normal control, sham-operation,experiement control group,minidose Edaravone pretreatment(1mg·kg^-1)and large dose Edaravone pretreatment(3mg·kg^-1).An embolus was placed at the origin of the middle cerebral artery by injection of an autologous single blood clot via an intraluminal catheter placed in the intracranial segment of internal carotid artery.Pretreatment with Edaravone vena caudalis injection 7 days.The neurological deficits were evaluated in a posture test after the ischemia.The concentration of LPA was quantified by ultraviolet spectrophotometry,The concentration of PLT was quantified by automation.The brain was removed immediately and cut into six coronal slices (2mm in thickness)by a rat brain slicer.HE dyeing to observe the histopathotogy of focal cerebral ischemia.The infarct size was measured by a computerized image analysis system.Results:(1)The large dose edaravone-treated group significantly(P＜0.05)improved the neurological deficits compared with the experiement control group.While there were no significant differences between the minidose Edaravone pretreatment group and the experiement control group(P＞0.05).(2)The concentration of plasma LPA in the experiement control group was higher compared with the normal control group(P＜0.05).The concentration of plasma LPA decreased significantly in large dose Edaravone pretreatment group(P＜0.05),while there were no significant differences between the minidose Edaravone pretreatment group and the experiement control group(P＞0.05).(3)The concentration of plasma PLT in the experiement control group was decreased compared with the normal control group(P＜0.05).There were no significant differences between the Edaravone pretreatment groups and the experiement control group(P＞0.05).(4)Histological analyses using H&E of brains revealed that the large dose edaravone-treated group can lighten the extent of cellular swelling and interstitial edema inbrain.It was showed that the large dose edaravone-treated group can protect the brain from injury after cerebral ischemia.(5)The large dose edaravone-treated group significantly(P＜0.05)reduce the cerebral infarction volume the extent of cerebral edema and destruction of ischemia compared with the experiement cotrol group.While there were no significant differences between the minidose Edaravone pretreatment group and the experiement control group(P＞0.05).Conclusions:(1)The concentration of plasma LPA increases differently after cerebral thromboembolism.(2)Pretreatment with large dose Edaravone can improve the repair ability of brain tissue in the course of ischemic and mitigate the impairment of neurons and quantity of apoptosis in penumbra,thus preventing the extension of cerebral infarction.Pretreatment with large dose Edaravone can decrease the concentration of plasma LPA in rats.(3)Our study suggests that the free radical scavenger edaravone could be a potent neuroprotector against brain ischemia injury by scavenging the free radical.