Alterations in expression of GFAPmRNA and correlated protein after cerebral ischemia/reperfusion in rats

Objective To investigate the changes of glial fiber acid protein(GFAP) and GFAPmRNA levels after brain ischemia/reperfusion injury in rats. Methods Focal cerebral ischemia was induced by occlusion of middle cerebral artery (MCAO) for 60min and followed reperfusion. Subsequently the levels of GFAPmRNA and correlated protein in ischemic cortex at different time were determined by RT-PCR and immunohistochemistry. Results The expression of GFAPmRNA was markedly increased 3d after reperfusion, while the correlated protein significantly increased by d7. After 30 d of reperfusion the levels of GFAPmRNA decreased to normal with the formation of colloid scar in the margin of ischemic core. Conclusion This study demonstrates that focal cerebral ischemia in rat results in continual response, a process often referred to as reactive astrogliosis, but astrocytes may play different roles in the pathophysiological process at different stage.