| Objective:To investigate the association between zonula occludens-1(ZO-1) and cerebral vasospasm(CVS) by observing the expressions of ZO-1 in the basilar artery after experimental subarachnoid hemorrhage(SAH) in rats. To observe the expression changes of MMP-9,ZO-1 and Cx43 and the effect after the intervention of MMP-9inhibitor SB-3CT. Then discuss the relations between the three and initially reveal the possible mechanism of CVS after SAH.Methods:1. Total 60 healthy male SD rats were randomly divided into 2 groups,SAH group and sham-injection group. Then,the SAH group was divided into 5 subgroups according to time points(1d,3d,5d,7d,14d). Twice autologous arterial blood injection into cistema magna was used to establish SAH model in rats. Moreover, the sham-injection group only accepted an equal volume of NS.The expression level of ZO-1 in basilar artery wall was analyzed by immunohistochemistry and western blot,the pathological and Wall morphology changes of the basilar artery were observed with HE staining.2. 50 healthy male SD rats were randomly divided into 4 groups,SAH group,sham-injection group,vehicle group and treatment group.Twice autologous arterial blood injection into cistema magna was used to establish SAH model in rats.The rats in the treatment group were injected of SB-3CT 0.2mg/0.1ml before the blood injection,while vehicle group accepted an equal volume of DMSO into the cisterna magan.The expression level of MMP-9,ZO-1 and Cx43 in basilar artery wall was analyzed by western blot, the pathological and Wall morphology changes of the basilar artery were observed with HE staining,and the expressions of ZO-1 and Cx43 were evaluated by immunohistochemistry method.Result:1. The pathological changes included varying degrees of arterial stenosis and endothelial dysfunction, among which the change on 3th day after SAH was the most significant. The inner luminal diameter on 3rd was about 44% of the sham-injection group’s, and the wall thickness was about 3.5 times of the sham-injection group’s.Then the arterial stenosis began to relief with the progress of time gradually, and it’s nearly normal on 14 th day.The expression of ZO-1 declined in SAH group, and reached the minimum on 3rd, then gradually recover. On the 14 th day,the level was nearly normal.2. The manifestations of SAH group and vehicle group included seriousness of arterial stenosis and endothelial dysfunction contrasted with sham-injection group. In the treatment group,the diameter was expanded obviously(about 1.7 times of SAH group),and the thickness was considerably decreased(about 59% of SAH group)with a statistical difference(p<0.01). Compared with sham-injection groups,the expressions of MMP-9 and Cx43 in SAH group were significantly increased,while the level of ZO-1 decreased. However,the expressions of MMP-9 and Cx43 in the treatment group declined obviously while the level of ZO-1 rose compared with SAH group.Conclusion:1. The SAH model in rats was successfully constructed. Meanwhile, the significant pathological changes in the basilar artery, arterial stenosis and wall thickness can be observed, it suggests CVS appears after SAH.2. The expression of ZO-1 in the basilar artery has decreased after SAH, and there is a negative correlationship between ZO-1 and the degree of CVS in the different point. It suggests ZO-1 may be involved in the mechanism of CVS after SAH.3. MMP-9 may be involved in the pathological process of CVS after SAH by degrading ZO-1 or upregalating the level of Cx43 or affactingthe their interaction.4. The inhibition of MMP-9( SB-3CT) can alleviate the process of CVS after SAH, and it may provide a new basis for prevention and treatment of CVS. |
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