Research On The Protection Of Urokinase With And Without Edaravone In Focal Cerebral Ischemia Model In Rats

Objective To explore the neuroprotective mechanism of edaravone after thrombolytic therapy by studying the effect of edaravone on the fibronectin(FN),cell appotosis,caspase-3 expression following thrombolytic therapy in urokinase after focal cerebral ischemia in rats.Methods The middle cerebral artery(MCA)of Sprague-Dawley rat was occluded by autologous blood clots.Urokinase was administrated by intravenous injection after 2 hours.Rats were randomly assigned to sham-operated group(sham group),saline control group(NS group),urokinase therapy group(UK group)and urokinase with edaravone group(UK+ED group).The infarction volume of brain was investigated by 2,3,5-Triphenyl tetrazolium chloride(TTC) coloring.The histological morphlogical damage of brain was investigated by hematoxylin-eosin(HE)staining. The permeability of blood-brain barrier(BBB) was evaluated based on leakage of Evans blue and the content of EB in the brain tissue was measured by spectrophotometry .The expression of FN of the four groups was analysed by immunofluorescence 24h after ischemia. Immunohistochemistry method was used to detect the expression of Caspase-3 and TUNEL staining were used to determine the number of TUNEL-positive apoptotic cells in the brain tissue.Results 1.In UK group,we found that urokinase significantly ameliorated the histopathological damage in brain.In UK+ED group,the histopathological damage in brain is futurer ameliorated.2.Cerebral ischemia couldnot be seen in sham operation.Infarction volume was lower both in UK and UK+ED compared to NS group(P<0.01),UK+ED group was significantly lower (P<0.01).3. Contrast to UK group,the combination of UK and ED significantly reduced EB content in the side of ischemia brain(P<0.01) 4.Immunofluorescence revealed basal lamina FN degradation in ischemic groups (all P <0.01),the expression was weaker in UK than NS and UK+ED group(P<0.05),NS was weaker than UK+ED(P<0.05).5. Compared with the sham operation group,the expression of TUNEL and Caspase-3 increased obviously in cerebral ischemia group(P<0.01).Contrast to UK group,the combination of UK and ED significantly decreased TUNEL and caspase-3 expression in the side of ischemia brain(P<0.01).Conclusion 1.Urokinase thrombolytic therapy significantly reduced the infarct size.urokinase with edaravone group could futurer reduced the infarct size. 2.Fibronectin may involve in the brain damage of ischemia/reperfusion after thrombolysis therapy.3.It is assumed that edaravone may relieve the damage of reperfusion to BBB by enhanced expressions of fibronectin,and reduce Infarction volume by lessen apoptosis.Thus,it had the effects of certain neural protection in thrombolysis.