The Relationship Between Caspase3,8 And Cerebral Vasospasm After Subarachnoid Hemorrhage

Objectives:To establish the model of cerebral vasospasm after subarachnoid hemorrhage in rabbits and to study the expression of Caspase 3,8 in the basilar artery after subarachnoid hemorrhage at various time point and the relationship between Caspase 3,8 and cerebral vasospasm .Methods: 1,Thirty six New Zealand rabbits were randomized into 2 groups: control group(n=6) and SAH group (n=30).Then the latter group was randomly divided into 5 groups according to the time:1d,3d,5d,7d,10d (6 per group) . Models of SAH were successfully induced via injecting autologous blood into the cisterna magna twice.Another 4 rabbits were used for the examination of the transmission electron microscope:2 control group and 2 SAH group(D7).The perfusion-fixation was performed for sacrifice of the rabbits in different time after the second blood injection in vivo and the basilar arteries were taken.The morphological changes of the basilar artery were observed under optical microscope and the lumen areas were measured to assess vasospasm in all groups and the ultrastructural changes of BA afte SAH were examined by TEM.2,Immunohistochemistry technique and TUNEL were used to observe the expression of Caspase3,8 and the apoptosis in the basilar artery.Results: 1,Compared with the control group, the basilar arteries in experimental groups demonstrate vascular walls thickening,endothelial cells shrinking, diameters and lumen areas significantly decreasing and the morphological changes according with cerebral vasospasm change.The basilar artery lumen areas were smaller in control group than those in SAH groups and the results were statistically significant(P<0.05). The TEM shows part of the vascular endothelial cells falling off , tight junction opening, endothelial cells gap increasing, the inside elastic membrane distorting and breaking, smooth muscle cells deformation,cytoplasm vacuole changing in experimental groups, while in the control group it reveals the vascular endothelial cells in succession, tight junction undamaged, the structure of the cytoplasm in good condition.2,Apoptosis cells were seen in the SAH groups through TUNEL and they appeared in day 1, reaching the highest in day 7,however,they were rare seen in the control group.There were statistically significant difference about the expression of Caspase3 and Caspase 8 in the basilar arteries between the control group and SAH groups (P<0.05). The expression of Caspase3 and Caspase8 in the basilar arteries appeared in day 1 and augmented in day 3,reaching the highest in day 5 and day 7 and decreasing apparently in day 10 .Conclusion:1,The New Zealand rabbits models that were established by injecting autologous blood into the cisterna magna twice are practical,and are reliable for experimental studies of vasospasm after subarachnoid hemorrhage in human .2,There is apoptosis in the basilar arteries of rabbits from cerebral vasospasm models.The expression of Caspase 3 and Caspase 8 increases apparently and have a certain time regularity . Caspase 3 and Caspase8 play roles in the process of apoptosis of endothelial cells in the basilar artery and in the occurrence of cerebral vasospasm after subarachnoid hemorrhage.