Role Of Cx43in Neuroprotective Effect Of Ischemia Preconditioning On Cerebral Ischemia/reperfusion Injury In Rats

Objective: To explore the neuroprotection of connexin43on cerebral ischemia/reperfusion injury after ischemia preconditioning in rats.Method: The middle cerebral artery occlusion rat models were established, andthe middle cerebral artery was occluded for2hours following with24hoursreperfusion. Healthy adult male Wistar rats were randomly divided into three groups,including sham group, ischemia/reperfusion group and ischemia preconditioninggroup. Neurological deficit scores of different group were evaluated with5-pointscoring method. Hematoxylin-eosin staining method was used to detect thepathology of brain tissue. Immunohistochemical method was used to evaluate the setof connexin43protein expression and changes. Western blot was used to detect theexpression of connexin43and phospho-connexin43protein.Results: The relevant results show that compared with the sham group, rats inischemia/reperfusion group appeared significant higher scores of neurologic deficits,a large area of focal cerebral infarction and brain tissue pathological changes, suchas: disordered arrangement of cells, red neurons, the concentration of cytoplasm,pyknosis, karyorrhexis and even the ghost cells. Compared with the ischemia/reperfusion group, the ischemia preconditioning can significantly reduce theneurological deficit scores, improve the histopathological changes caused bycerebral ischemia/reperfusion. Immunohistochemistry showed that compared withthe sham group, the expression of connexin43protein increasd in ischemia/reperfusion group (p<0.05). Compared with the ischemia/reperfusion group, theexpression of connexin43reduce in ischemia preconditioning group (p<0.05). Nodifferences in the expression of phospho-connexin43protein were observed in thethree groups (p>0.05).Conclusions: The results suggest that the cerebral ischemia/reperfusion injurymay be closely related with the increasing expression of connexin43protein and thereduction of connexin43protein participated in a mechanism that ischemiapreconditioning could improve the cerebral ischemia/reperfusion injury.