Abstract: 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. Methods Total 60 healthy male Sprague-Dawley (SD) rats were randomly divided into 2 groups, SAH group and shaminjection group. Then, the SAH group was divided into 5 subgroups according to time points (1 d, 3 d, 5 d, 7 d and 14 d). 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 normal saline (NS). The expression level of ZO-1 in basilar artery wall was analyzed by immunohistochemistry and Western blot assay. The pathological and wall morphology changes of the basilar artery were observed with HE staining. Results The pathological changes included varying degrees of arterial stenosis and endothelial dysfunction were found by HE staining, and the changes were the most significant on the 3rd day after SAH. The inner luminal diameter was about 44% of the sham-injection group on the 3rd, and the wall thickness was about 3.5 times of the sham-injection group. Then the arterial stenosis began to relief with the progress of time gradually, and it’s nearly normal on the 14th day. The expression of ZO-1 declined in SAH group, and reached the minimum on the 3rd, then gradually recover. On the 14th day, the level was nearly normal. Relativity analysis suggested that the expression of ZO-1 was positively correlated with the inner luminal diameter of the basilar artery (r=0.719, P＜0.05), and negatively correlated with the wall thickness (r=- 0.686, P＜0.05). Conclusion The expression of ZO-1 in the basilar artery decreases after SAH, and there is a consistent relationship between the expression of ZO-1 and the change degree of CVS in the different points, which suggests ZO-1 may be involved in the mechanism of CVS after SAH, and it’s possible to enhance the signal transduction of vasoconstriction by affecting the function of gap junction.

Key words: subarachnoid hemorrhage, vasospasm, intracranial, tight junction proteins, basilar artery, ZO-1；mechanism