Objective:To explore the vascular protective effects and mechanism of fasudil in rats after experimental subarachnoid hemorrhage.Methods:Forty-eight rats were divided into sham-operated control group

subarachnoid hemorrhage group and treatment group.Model induced by autologous blood injection into cisterna magna

and rats were killed on day 1

day 3

day 7 and day 14 after subarachnoid hemorrhage.Morphological change of basilar artery was observed by light microscopy

diameter and wall thickness of basilar artery were measured respectively.eNOS expression in basilar artery was detected by immunohistochemical SP method.Results:Vasospasm of basilar artery initiated on day 1

reached its peak on day 3

and mitigated on day 7 after SAH.eNOS expression decreased at each time point in SAH group.Compare with SAH group

diameter and wall thickness of basilar artery were significantly reduced on day 3 and day 7 in treatment group(P<0.05)

and eNOS expression also statistically increased on day 3

day 7 and day 14(P<0.05).Conclusion:Fasudil can effectively relieve post-SAH cerebral vasospasm.Upregulation of eNOS expression in the arterial wall might be one of important mechanisms.