ABSTRACT
Aim To observe the infarct size, apoptosis of the neurocytes,the expressions of Bcl-2 and Bax pro-teins after focal cerebral ischemia-reperfusion injury (CIRI) in the brain tissue of rats and the protective effects of rofecoxib.Methods The model of local CIRI was induced by reversible middle cerebral artery occlusion (MCAO) with inserting a thread through internal carotid artery,2 h occlusion followed by 24 h reperfusion.Rofecoxib was administrated (ig) at the reperfusion initiation. Using TTC staining technique to measure the infarct size of brain,TUNEL technique to examine apoptosis of the neurocytes,immunohistochemical method to examine the expression level of Bcl-2 and Bax proteins in brain tissue.Results After focal CIRI,the infarct focus of brain was showed,both apoptosis rate of the neurocytes and Bax protein expression were significantly increased and the ratio of Bcl-2 to Bax was significantly reduced.With the use of both 1.12 and 2.24 mg?kg -1 doses of rofecoxib,the brain infarct size was dramatically reduced. With the use of 2.24 mg?kg -1 dose of rofecoxib,both apoptosis rate of the neurocytes and Bax protein expression were significantly decreased,both Bcl-2 protein expression and the ratio of Bcl-2 to Bax were significantly higher than that in the group Model.Conclusion The highly selective COX-2 inhibitor rofecoxib may increase Bcl-2 protein expression and decrease Bax protein expression then increase the ratio of Bcl-2 to Bax and so reduce the neurocytes apoptosis in brain tissue thus significantly improve the brain injury after CIRI.