Initial Study Of Cerebral Vasospasm In A New Animal Subarachnoid Hemorrhage Model

Subarachnoid hemorrhage(SAH) often lead to poor prognosis and 22～25% mortality in patients with cerebrovascular disease.The most common complication of SAH is cerebral vasospasm(CVS),CVS-induced cerebral ischemia or infarction is an important cause of disability and death.To date,it is still very difficult to deal with CVS. Although many breakthroughs have been achieved on the basis of substantial in-depth study,few medicines and treatment obtain the actual clinical value.The aim of this study is to set up an animal model which is an accurate simulation of CVS after SAH,further proved the mechanism of CVS,obtain a reliable indicator related to CVS,and on this basis find more effective medicines and treatment.PartⅠEstablishment of Rabbit Subarachnoid hemorrhage ModelObjective:To set up a new experimental model of subarachnoid hemorrhage. Methods:A rabbit model was established by endovascular puncture in Internal Carotid Artery(ICA) through femoral artery.60 rabbits were randomly divided into 10 groups(control,Sham-operation,0h,3h,6h,12h,1d,3d,7d,14d after SAH).After cerebral angiography at different time points,all rabbits were taken perfusion-fixation. The basilar artery cuts were stained with HE for morphologic examinations.The artery diameter and vascular wall thickness were determinated by image analysis systems analysis.Results:The biphasic process of CVS included acute phase spasm(12h after SAH) and delayed phase spasm(7d after SAH) in rabbit model made by endovascular puncture method.Conclusion:The model made by endovascular puncture method can simulate the pathologic process of CVS after SAH. PartⅡMechanism of Vascular Endothelial Hyperplasia in course of Cerebral VasospasmObjective:To study the mechanism of vascular endothelial hyperplasia in course of cerebral vasospasm after subarachnoid hemorrhage.Methods:The serum levels of IGF-1,FGF,TGF-β1 collected from 60 rabbits at separate time points(control, Sham-operation,0h,3h,6h,12h,1d,3d,7d,14d after SAH) were detected by ELISA and statistically analyzed.For morphologic examinations,Vascular Smooth Muscle cells(VSMCs) of basilar artery were indicated immunohistologically with an antibody againstα-actin,VSMCs proliferation of basilar artery was examined by Proliferation Cell Nuclear Antigen(PCNA),and PCNA positive cells were counted for statistically analysis. Results:The serum levels of IGF-1,FGF,TGF-β1 were all abnormal.The valley value of TGF-β1 arrived at 12h after SAH,the peak value of FGF arrived at 3d after SAH,the peak value of IGF-1 arrived at 6h after SAH,the peak value of PCNA positive cells per cut arrived at 7d after SAH and maintained till 14d.Vascular smooth muscle cell proliferation and shift can been observed in the delayed phase of CVS.Conclusion:Vascular endothelial hyperplasia participate the spasm process in the delayed phase of CVS.PartⅢPrevention of Cerebral Vasospasm with Trapidil in Animal Subarachnoid Hemorrhage ModelObjective:To study the effects of Trapidil on CVS in different periods and its mechanism.Methods:12 rabbits intake trapidil after SAH,The serum levels of IGF-1(6h after SAH),FGF(3d after SAH),TGF-β1(12h after SAH) collected from all rabbits at its peak(valley) value of time point were detected and statistically analyzed.After cerebral angiography,the basilar artery cuts obtained separately in the acute spasm period(12h) and delayed spasm period(7d) were stained with HE for measuring the artery diameter and wall thickness,and observed throughα-acting and PCNA immunohistochemistry.At the same time,the PCNA-positive cells were counted.All measured values were statistically analyzed among control group,SAH group and intaking trapidil group at same time point. Results:Trapidil can decrease serum level of FGF,and increase serum level of TGF-β1. This medicine can not relieve spasm of basilar artery in in acute phase,but can relieve spasm of basilar artery in delayed phase.Conclusion:Trapidil had no significant effect on CVS in acute phase,and had good control for CVS in delayed spasm.