蛛网膜下腔出血后蛛网膜纤维化的研究

目的 探讨蛛网膜下腔出血(subarachnoid hemorrhage,SAH)后蛛网膜纤维化的发生机制.方法 实验大鼠分成对照组、实验组、治疗组,使用放射免疫法(RIA)测定蛛网膜中透明质酸(HA)、层黏连蛋白(LN)、Ⅲ型前胶原氨基端肽(PⅢNP)、Ⅳ型胶原的含量.应用电镜观察蛛网膜细胞的形态及蛛网膜胶原纤维分布情况.结果 RIA 测量的4种细胞外基质中,PⅢNP在出血后增高最明显,LN与HA也明显升高,而Ⅳ型胶原变化不明显.应用地塞米松治疗后PmNP明显降低.电镜下发现蛛网膜细胞在出血后其生物活性增强,蛛网膜下腔的胶原纤维在1周左右开始明显增多,持续3周以上,地塞米松治疗后蛛网膜细胞线粒体密度相对较低,蛛网膜胶原纤维较稀疏.结论 蛛网膜下腔出血后细胞外基质明显增加,参与蛛网膜纤维化.地塞米松可减轻蛛网膜下腔出血后蛛网膜纤维化,为防治蛛网膜下腔出血后脑积水提供新的思路.

Arachnoidal fibrosis after subarachnoid hemorrhage

Objective To study the mechanism of arachnoidal fibrosis after subarachnoid hemor- rhage. Methods Rats were divided into control group, experiment group and treatment group. Radioim- munoassay (RIA) was employed to detect the levels of hyaluronic acid, laminin,type Ⅲ precollagen and type Ⅳ collagen in the arachnoid membrane. In the meantime, arachnoid cell's morphology and collagen distribution in the subarachnoid space were investigated by electron microscope. Results Results of RIA detection showed increase of Type Ⅲ precollagen level (peak at the second week), obvious higher levels of LN and HA but insignificant change of type IV collagen after subarachnoid hemorrhage. However, dexam- ethasone treatment decreased type Ⅲ precollagen level. Electron microscope found that arachnoid cells pres- ented accentruated bioactivity after subarachnoid hemorrhage, with significant increase of arachnoidal colla- gen fibers from one week after suharachnoid hemorrhage, continuing for 3 weeks. Dexamethasone treatment resulted in low density of mitochondria and sparsed arachnoidal collagen fibers. Conclusions Extracellu- lar matrix (ECM) increases in arachnoid membrane after subarachnoid hemorrhage and participates in a- rachnoid fibrosis. Dexamethasoue can relieve arachnoidal fibrosis after subarachnoid hemorrhage, as pro- rides fresh way for prevention and treatment of post hemorrhagic hydrocephalus.