The expression of TGF-β1 protein in rat after focal cerebral ischemia and reperfusion

Objective To study the expression of transforming growth factor beta1 (TGF β1) at different time points of reperfusion after middle cerebral artery occlusion (MCAO).Methods The expression of TGF β1 protein was measured by immunohistochemical technology.Results From the sixth hour of reperfusion, the TGF β1 positive cells at ischemic area in operation groups increased as compared with those in sham operation and control groups (P0.01).Only a few vascular endothelial cells showed a weak labeling after staining with TGF β1 antiserum in normal controls and sham operated controls. In MCAO group,the most marked up regulation occurred in vascular endothelial cells and smooth muscle cells of the infarct and the border zones. Neurons and gliacytes in the border zones showed a moderately intense expression. Occasionally some leptomeningeal and cortical vascular endothelial cells and smooth muscle cells showed a positive staining reaction.Conclusion High level of TGF β1 expression persists for a long time following ischemia reperfusion injury of brain and is an endogenous self protective mechanism,which helps to maintain survival of neurons and recover neural function.