Abstract: Aim To ascertain whether defibrase has the protective effect against reperfusion injury after cerebral i schemia.Methods 70 renovascular hypertensive rats(RHR) were randomly divided into defibrase group, control grouPand sham-operated group.Reversible middle cerebral artery occlusion(MCAO)models were produced by the modified.Long as method ,and reperfusion was begun 2 hours after occlusion.Rats in the defibrase grouPwere given defibrase 10 U·kg^-1body weight via femonal intraveneous injection, and in the control grouPwith the same amount of saline.The brain pieces were processed by TTC and HE staining and the infarct size, brain micro vessels damage and secondary bleeding were compared between the two groups.Results The volume of infarction in the defibrase grouPwas obviously smaller than in the control group, the damage of brain micro vessels was less severe ,and the bleeding lesions under optical microscope were less than in the control group.Conclusion Defibrase has protective effect against reperfusion injury post cerebral ischemia.

Key words: reperfusion after cerebral ischemia, defibrase, rat