A study on expression and significance of GDNF in cerebral tissue of rats subjected to cerebral ischemia-reperfusion

Objective To observe the expression of glial cell line-derived neuro-trophic factor(GDNF)in cerebral tissue of rats subjected to cerebral ischemia-reperfusion,and its role in rats following cerebral ischemia-reperfusion.Methods The model of focal cerebral ischemia was made by occluding middle cerebral artery(MAC)for 2h and reperfusion for 3～120h,HE staining was used to investigate the histological features of ischemic cerebral damage,the immunohistochemical method was used to observe the expression of GDNF in brain tissue in rats.Results The neurons presented irreversible degeneration at 12h of reperusion.At 24h,the ischemic area in the preoptic area,striautm and cortex devaioped into infarct form.GDNF Positive cells were not detected in normal and sham-operated rats.During the course of reperfusion,The number of GDNF positive cells peaked at 3h of reperfusion,then gradually decreased.Quantitation analysis reveals that the number of GDNF immunoreactive cells in the ipsilateral-ischemic area significantly(P0.01)decreased 12、24、48、72and 120h after MAC occlusion compared with that of 3h after MAC occlusion.Conclusion During cerebral ischemia-reperfusion,the degenerative and died nenron do not express GDNF and neurons in peri-ischemic area and no-ischemic area showed GDNF immunoreactivity.These results suggest that GDNF has a potential to protect neurons from in jury.Activated microglias or macrophages can express GDNF during ischemia injury The study provides a certain referance value to use GDNF in early phase of cerebral ischemic to decrease cerebral in jury.