Effects Of GluN2C Subunit On Focal Cerebral Ischemia-reperfusion Injury In Rats

Objective:In this study,we applied the rat model of focal cerebral ischemia-reperfusion to explore the expression pattern of GluN2 C subunit over time after ischemia-reperfusion,and to explore the specific role of GluN2 C subunit on the focal cerebral ischemia-reperfusion in rats.Methods:Seventy healthy adult male(SPF)SD rats were randomly divided into 7 groups,including 1 normal control group,1 sham operation group and 5 ischemia-reperfusion groups(1h,6h,12 h,24h and 72 h reperfusion after 2h ischemia).After neurologic score,SD rats in each group were sacrificed.TTC staining was used to measure the size of cerebral infarction,HE staining was used to observe the morphological changes of brain tissue cells,and immunohistochemistry was used to determine the expression of GluN2 C subunit in brain cells.Results:1.The Score of Neurological Deficit After 2h cerebral ischemia,the neurological function score of rats increased with the prolongation of reperfusion time.The score of neurological deficit reached the peak at 24 h and decreased at 72 h,but there was no statistical significance compared with the 24 h group.2.Measuremen to Infarct Volume There was no cerebral infarction in the normal control group and the sham operation group.The cerebral infarct volume in the ischemia-reperfusion groups increased with the prolonging of reperfusion time.Compared with the normal control group and the sham operation group,the cerebral infarct volume in each group of ischemia-reperfusion groups was statistically significant(P<0.001),but there was no statistically significant difference between the ischemia-reperfusion group for 72 h and the 24 h group.3.Pathological changes in brain tissue In the normal control group and the sham operation group,no abnormalities were observed in the morphological structure of brain tissue,the HE staining was darker,the morphological structure of neurons was normal,and the nuclear membrane and nucleoli were obviously clear.There was no obvious pathological change.In ischemia-reperfusion group for 1h,a few neurons were slightly cavitated.In the ischemia-reperfusion groups for 6h and 12 h,the HE staining was shallow and uneven,and many neurons had obvious vacuolar changes and loose structure.In the ischemia-reperfusion group for 24 h,the HE staining was light and uneven,the number of neuronal cells was significantly reduced,the cell had vacuolar changes,and the nuclear were pyknotic and disappeared.In the ischemia-reperfusion group for 72 h,a large number of neurons were necrotic,the structure was loose,and the nuclei were severely pyknotic or even disappeared.4.Expression of GluN2 C subunit There was a small amount of GluN2 C subunit expression in the normal control group and the sham operation group,and the expression in the sham operation group was slightly higher than that in the normal control group,and the difference was not statistically significant.In the experimental groups,the expression of GluN2 C subunit began to increase at 1h reperfusion after 2h ischemia,and continued to increase at 6h and 12 h reperfusion after 2h ischemia.The expression of GluN2 C subunit reached the highest level at 24 h reperfusion after 2h ischemia,and the expression of GluN2 C subunit began to decrease at 72 h reperfusion after 2h ischemia,but the expression of GluN2 C subunit in the ischemia-reperfusion group for 72 h was still higher than that in the normal control group and the sham operation group,with statistical significance(P<0.001).Conclusion:After cerebral ischemia-reperfusion in rats,elevated expression of GluN2 C subunit plays a role in brain injury.