Role Of Apoptosis In Vasospasm Artery Endothelial Cells Induced By Subarachnoid Hemorrhage

Spontaneous subarachnoid hemorrhage(SAH) is a commonly hemorrhagic cerebrovascular emergency,and its most deadly complication is cerebral vasospasm, especially the DIND, which induces Hypoxic and ischemic brain damage,following a high morbidity and mortality .Despite intensive research efforts to cerebral vasospasm pursuant to SAH for more than 50 years, no consistent and integrated theory system exists, and its true mechanism and secondary impairment remain unclear. It has still been elusive for effective preventative and therapeutic treatments.Recent years some scholars considered that apoptosis of endothelial cells (programmed cell death, PCD) after SAH may play an important role in the mechanism of CVS after SAH.AIM: It is not clear about the mechanism of CVS after SAH, and it has still been elusive for effective preventative and therapeutic treatments. With the profoundly clinical and laboratory research into CVS, it is not confined to objective signs such as diminution of cerebral vessels and decreasing of regional cerebral blood flow(rCBF) for clinical therapy,but trying to find a new angle of therapeutics to aim directly at mechanism of CVS following SAH. In recently, the it has been focused on that the role of apoptosis wallcells in the mechanism of CVS after SAH.TRAIL is a newly discoveried TNF family member.it can induce the cell apoptosis especially thoughy its death receptor DR4 and DR5.We study the role of Tumor-related apoptosis-inducing ligand(TRAIL) and its recepor-DR4 , recepor-DR5 in apoptotic endothelial cells of vasospasm artery after subarachnoid hemorrhage.To supply a new thought and basis for effective method to prevent and treat CVS following subarachnoid hemorrhage (SAH)METHODS: Fifty-four rabbits were used in the present study. The population was randomly divided into three groups: control group, subarachnoid hemorrhage(SAH) group and sham-operated group and the groups were sacrificed respectively on pre-operation and 0, 2, 4 and 7d (6 per group). The SAH models were made by double-hemorrhage method. In SAH group rabbits, CVS was produced by injecting 2.5ml of autogenous arterial blood into subarachnoid space through cisterna magna two times .In sham- operated group, rabbits were injected twice with 2.5 ml of normal saline 2 days apart. Cerebral vasospasm(CVS) were confirmed by angiogram. TRAIL protein and its receptor DR4, DR5 expression positive number and apoptotic cell number were determined using immunohistochemical technique and TdT-mediated dUTP-biotin nick end labeling (TUNEL).RESULT: Angiographic vasospasm began on Od and peaked on 2d to 4d. In group control rabbits, cerebral angiography showed the basilar arteries' (BA) diameters were 0.70±0.03mm, There were significant differences between control and sham-operated groups' of the basilar arteries' (BA) diameters (P<0.01). In TUNEL studies, control rabbits did not demonstrate apoptosis in endothelial cells of the basilar arteries. CVS rabbits beginning on Od, apoptosis were noted in endothelial cells. And it is significant differences defence control groups (P<0.01). In the immunohistochemical study, TRAIL,...