The Change Of Neuropeptide Y Nerve Fibers On Cerebral Arteries And The Level Of Neuropeptide Y In Plasma After Subarachnoid Hemorrhage In Rats

Objective In order to explore the relationship between neuropeptide Y nerve fibers on cerebral artery, the level of neuropeptide Y in plasma after subarachnoid hemorrhage(SAH) in rats and cerebral vasospasm(CVS),and to offer morphological data for pathogenesis of SAH-induced CVS. Methods 42 wistar rats were divided into normal group, sham-operated group, experimental groups. The experimental groups were subdivided into five groups that were 12 hours,1, 2, 3,7days groups after subarachnoid hemorrhage,the number of each group was 6. SAH was induced by immediate injection of autologous arterial blood, which was freshly withdrewn from femoral artery,into the cisterna magna . The sham-operated group received a cisternal injection of buffered normal saline in place of blood. The density of neuropeptide Y innervation on the cerebral arteries and level of neuropeptide Y in plasma were measured with immunohistochemistry ABC and radioimmunoassay technique respectively. Results The brown liner structures were observed on anterior cerebral artery ,middle cerebral artery ,posterior cerebral artery , basilar artery of the normal rats. The density of neuropeptide Y nerve fibers on cerebral arteries of 12 hours ,1 day, 2 days groups after SAH was lower than that of normal rats,especially the group of 12 hours after SAH.The level of neuropeptide Y in plasma of the rats after SAH 12 hours, 1 day, 2 days, 3 days were higher than that of normal rats(P<0.05). Conclusion It suggests that the decrease of the neuropeptide Y nerve fibers and increase the level of neuropeptide Y in plasma might play an important role in the maintenance and the development of SAH-induced cerebral vasospasm and in the neurogenesis regulation of cerebral artery.