The Effect And Mechanism Of Ethyl Pyruate On Delayed Cerebral Vasospasm After Subarachnoid Hemorrhage

Objective: To observe the degree of cerebral vasospasm(CVS)on rats after subarachnoid hemorrhage(SAH)at different times,and to probe into the effects and mechanism of ethyl pyruvate(EP)on CVS following SAH.Methods: 50 SD rats in a health status were split into five groups randomly: sham group,SAH-3d group,SAH-5d group,SAH-7d group and SAH-9d group(n=10).In sham group,0.3 m L saline were injected into cerebellomedullary cistern at double times,and SAH group was built by double cisternal injection each time with 0.3 m L autologous blood.The degree of CVS and neurological function were observed.48 SD rats in a health status were split into three groups randomly: sham+saline group(equal volume),SAH+saline group(equal volume)and SAH+EP group [100 mg/(kg · d)](n=16).On day 7 the degree of CVS,neurological function and cell apoptosis of basilar artery were observed.Also the expressions of p-Akt,Bcl-2,Bax and cleaved caspase-3 were examined on day 7.Results: On day 3 CVS was significantly increased,and decreased on day 5,significantly increased to top level on day 7,and decreased on day 9 by degrees.On day 7,the neurological scores was significantly decreased in SAH+saline(equal volume)group compared with sham+saline group(equal volume).Compared with sham+saline group(equal volume),CVS and cell apoptosis of basilar artery in SAH+saline group(equal volume)were significantly increased on day 7.Compared with sham+saline group(equal volume),the expressions of cleaved caspase-3 and Bax in SAH+saline group(equal volume)were significantly up-regulated,while the expressions of p-Akt and Bcl-2 in SAH+saline group(equal volume)were significantly down-regulated on day 7.On day 7,the neurological scores was significantly increased in SAH+EP group [100 mg/(kg · d)] compared with SAH+saline group(equal volume).Compared with SAH+saline group(equal volume),CVS and cell apoptosis of basilar artery in SAH+EP group [100 mg/(kg · d)] were significantly decreased on day 7.Compared with SAH+saline group(equal volume),the expressions of cleaved caspase-3 and Bax in SAH+EP group [100 mg/(kg · d)] were significantly down-regulated,while the expressions of p-Akt and Bcl-2 in SAH+EP group [100 mg/(kg · d)] were significantly up-regulated on day 7.Conclusion: The double hemorrhage model rat has most serious CVS on day 7.EP has a relieving effect on delayed CVS following SAH,and its mechanism may be bound up with the suppression of cell apoptosis through PI3K/Akt signaling pathway.