| Preface Subarachnoid hemorrhage(SAH) is a commonly hemorrhagic cerebrovascular emergency,and its most deadly complication is cerebral vasospasm, 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 preventive and therapeutic treatments.Recent years some scholars considered that apoptosis (programmed cell death ,PCD) after SAH may play an important role in the delayed neuronal death(DND).Objective Main hazards of Cerebral vasospasm (CVS) following subarachnoid hemorrhage (SAH) is that it can bring about ischemic and anoxic neurological deficits.With the profoundly clinical and laboratory research into CVSjt is not confined to objective signs such as diminution of cerebral vessels and decreasing of regional cerebral blood flow(rCBF) for clinical therapy,but tryine to find a new angle of therapeutics to aim directly at secondary brain injury from CVS following SAH . To supply a new thought and basis for-4-effective method to prevent and treat brain injury after CVS following subarachnoid hemorrhage (SAH) ,the experiment detected the expression changes of bcl-2 and bax mRNA in rabbit hippocampus during CVS following experimental SAH.Methods SAH was induced in 52 NewZealand rabbits.(l)The population was randomly divided into three groups: normal control group with 6 rabbits.SAH group with 24 ones and sham operated group with 24 animals. Both SAH group and Sham operated group animals were observed at Od,ld,3d and 7d following SAH with each time points 6 animals.(2) CVS model after SAH was developed by injecting arterial blood twice through the citerna magna 48 hours apart. In SAH group rabbits, CVS was produced by injecting 2.5ml of autogenous arterial blood into subarachnoid space through cisteraa magna two times .In sham- operated group, rabbits were injected twice with 2.5 ml of normal saline 2 days apart. (3)The control group rabbits have undergone cerebral angiography without any other dealings before being killed just at the same day. After transcardic perfusion , each animal'hippocampus was removed and the total RNA in it was extracted by the guanidine thiocyanate method. The other groups rabbits went through cerebral angiography before and on SAH days at their each time points.The next step is extraction of the total RNA of hippocampus from each rabbits after their sacrifices.R(4)everse transcriptase-poiymerase chain reaction (RT-PCR) technique combined with computerized Gel Imaging system was used to detect the expression changes of bcl-2 and bax mRNA at each time pointes in rabbit hippocampus during CVS following experimental SAH.The iabworks manipulation software was used in positive strip density calculation and scan. The relative quantification of mRNA was acquired by the ratio of the density of positive stip to the corresponding one of Beta actin strip .All data in this study were expressed as the mean?the standard deviation .Both X2-test and Student t-test was used to compare the difference between the groups.o-Results (1) In group control rabbits, cerebral angiography showed the basilar arteries' (BA) diameters were 0.70 ?.122mm; In group sham-operated rabbits, the diameters at the different time points were as follows: 0 day,0.65?0.132mm; 1 d , 0.68?0.141 mm; 3 d , 0.70?0.129 mm; 7 d , 0.59?0.146 mm; The corresponding data of SAH group animals" BA diameters at the same time points were 0.47?.072mm at 0 day. 0.52?.077mm at 1 day, 0.45?.068mm at 3 day and 0.42 ?0.070mm at 7 day.(2) The expression level of bcl-2 mRNA at each time points in hippocampus of sham-operated group rabbits kept correlatively stable. The expression level of bcl-2 mRNA in hippocampus decreased from day 1 in SAH group, reached minimum at day 3 and remained sign... |
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