【作者】 钱聪；

【导师】 王义荣；

【作者基本信息】 浙江大学 ， 神经外科， 2007， 硕士

【摘要】 背景：慢性脑积水(chronic hydrocephalus, CH)是蛛网膜下腔出血(subarachnoid hemorrhage, aSAH)常见的并发症之一，严重影响了患者的预后。此类型慢性脑积水的发病机制尚未完全明确，总体上归纳为脑脊液分泌过多、循环受阻、吸收障碍或三者兼而有之。现有研究资料表明蛛网膜下腔出血所致的慢性脑积水与蛛网膜纤维化(arachnoidal fibrosis, AF)有非常密切的关系。因此，对蛛网膜细胞功能及蛛网膜纤维化病理生理的研究对治疗或者预防慢性脑积水有重要意义。目的：建立大鼠枕大池两次注血蛛网膜下腔出血模型，研究蛛网膜下腔出血后蛛网膜细胞与蛛网膜纤维化之间的关系，观察在地塞米松(dexamethasone, DXM)干预后蛛网膜细胞功能的变化以及在预防蛛网膜纤维化中的作用。方法：实验分成3组：蛛网膜下腔出血空白对照组，蛛网膜下腔出血并腹腔给予地塞米松治疗组，蛛网膜下腔出血并鞘内给予地塞米松治疗组。分别在模型制作成功后的第3天、第7天、第14天、第21天、第28天处死大鼠，然后在手术显微镜下取蛛网膜标本并—80摄氏度保存。使用放射免疫法测定蛛网膜中含氨基末端前肽的Ⅲ型前胶原(typeⅢprecollagen)、透明质酸(hyaluronic acid, HA)、Ⅳ型胶原(typeⅣcollagen)、层粘连蛋白(laminin, LN)的含量。分别在模型制作成功后的第3天、第7天、第21天处死大鼠，并在手术显微镜下取蛛网膜标本并在戊二醛中固定保存，然后在电子显微镜下观察蛛网膜细胞的形态及蛛网膜下腔的胶原纤维分布情况。结果：两次枕大池注血法制作的大鼠蛛网膜下腔出血模型效果良好，完全达到实验的要求。在RIA法测量的四种细胞外基质中，含氨基末端前肽的Ⅲ型原胶原在出血后增高明显，Ⅳ型胶原与透明质酸则基本不变，而层粘连蛋白则降低。在地塞米松治疗组中含氨基末端前肽的Ⅲ型前胶原明显较非治疗组降低，Ⅳ型胶原、透明质酸、层粘连蛋白则各组之间无明显差异。电子显微镜观察结果，蛛网膜细胞在出血后其生物活性明显增强，蛛网膜下腔的胶原纤维在一周左右开始明显增高，持续3周以上，在3组之间地塞米松治疗的2组蛛网膜细胞线粒体密度相对较低，但蛛网膜下腔的胶原纤维各组间并无明显差异。结论：枕大池两次注血法是一种比较简单可靠的建立大鼠蛛网膜下腔出血模型的方法。在蛛网膜下腔出血后，蛛网膜细胞在炎症因子的作用下细胞外基质明显增加(主要为Ⅲ型胶原)可能参与蛛网膜纤维化。在地塞米松干预组中细胞外基质(主要为Ⅲ型胶原)明显下降，其机制可能为通过减轻出血后蛛网膜细胞对非特异炎症反应从而减轻蛛网膜纤维化，使脑脊液循环及吸收得以改善而达到预防或者治疗慢性脑积水的目的。更多还原

【Abstract】 Background: Chronic hydrocephalus, that was one of the common complication of subarachnoid hemorrhage ( SAH ) , severely influences patient’s prognosis.The mechaniccsm of the chronic hydrocephalus caused by subarachnoid hemorrhage was still unclear, generally consists of cerebraspinal fluid(CSF) over-secretion, CSF circulation block, absorption disorders or both of them. Recent resources showed that chronic hydrocephalus caused by subarachnoid hemorrhage was in close relationship with arachnoidal fibrosis. Objective: To set up rat models of SAH by cisterna magna puncture and arterialblood injection; to study the relationship between arachnoid cell and arachnoidal fibrosis; and to clarify dexamethasone’s (DXM) effects on preventing arachnoid fibrosis and chronic hydrocephalus. Method: The twice blood injection in cisterna magna was used for modeling. Andthe rats were divided into 3 groups: the group1 was subarachnoid hemorrhage treated without DXM (blank control), the group2 was subarachnoid hemorrhage treated with DXM intraperitone- ally, and the group3 was subarachnoidhemorrhage treated by DXM intrathecally. To detect hyaluronic acid, type IV collagen, laminin and type III precollagen in the arachnoid membrane by RIA method. The electron microscope was used to detect arachnoid cell’s morphology and collagen distribution in the subarachnoid space. Result: The twice blood injection in cisterma magna could be a simple but effectivemethod in SAH modeling. The type III precollagen increased and 2 week later began to decrease, hyaluronic acid and type IV collagen fluctuated little, laminin decreased constantly; among these 3 groups, DXM group caused type III precollagen lower than the blank control group. For electron microscope observation we discovered arachnoid cells presented lower mitochondria density and less collagen in subarachnoid space in DXM treatment groups. Conclusion: The twice hemorrhage models was a simple and repeatable model for expe- rimental subarachnoid hemorrhage. One of the extracellular matrix (ECM), especially increased in both arachnoid cell plasma or subarachnoid space and hyaluronic acid, type IV collagen and laminin were almost stable, thatsuggested that type III collagen was one of the crucial factors on arachnoid fibrosis following the subarachnoid hemorrhage. Compared with the DXM ungiven group, the type III collagen in the DXM given group significantly decreased. It suggested that the DXM had effects on improving arachnoid fibrosis probably by easing nonspecific inflammatory reaction to improve CSF circulation and absorption.更多还原