The Expression of Survivin,Bcl-2 and Apoptosis after MCAo and Reperfusion in Renovascular Hypertensive Rats

AIM:To study expression of Survivin and Bcl-2 and cellular apoptosis in brain after MCAo and reperfusion in renovascular hypertensive rats. Methods:Fifties renovascular hypertensive rats weighting 290～310 g without stroke were randomly divided into two groups:single ischemia and reperfusion,and sham-operated group(25 each group). The middle cerebral artery occlusion (MCAo) was made by intraluminal vascular suture for 2 h and reperfusion in the rats, but MCAo was not performed in sham-operated group. The cell counts of Survivin and Bcl-2 with immunohistochemical staining and the cellular apoptosis with TUNEL staining methods were measured, respectively, in coronal sections of brain after reperfusion (6, 12, 24, 48 and 72 hours). Results: ① The Survivin protein had expressed at 6 h after reperfusion, and its expresssion was intensified until 72 h. ② The Bcl-2 protein had expressed at 6h after reperfusion, and reached its highest level at 24 h, then declined gradually. ③ The number of apoptotic cells increased with the development of reperfusion, and reached its highest level at 72 h. No positive cells of Survivin and Bcl-2 protein but 0～2 apoptotic cells could be discovered in brain section from sham-operated animals and in the opposed side to ischemia from the other groups animals.Conclusion: Expression of Survivin and Bcl-2 protein increases and apoptosis exists after focal cerebral ischemia and reperfusion in rats' brain, cerebral ischemia can enhance the expression of Survivin and Bcl-2 protein. Cellular apoptosis may contribute to the ischemic lesion.