兔实验性蛛网膜下腔出血后脑血管超微结构的病理特征与动态变化

目的探讨蛛网膜下腔出血（SAH）后脑血管的超微结构特征与动态变化，以圾这种改变在迟发性脑血管痉挛（CVS）中的作用机制。方法对日本大耳白家兔采用枕大池二次注血法制做SAH模型。动物随机分为SAH组、盐水对照组、穿刺对照组和正常组，于注血后1h、第3天、第5天、第7天、第10天灌注固定，留取基底动脉标本，在光镜和电镜下动态观察基底动脉的病理和超微结构的改变。结果光镜下SAH模型组的主要表现是血管壁增厚，管腔狭窄，内皮细胞变性、肿胀，染色质不均，空泡形成；内弹力膜迂曲皱褶或断裂。电镜下超微结构的主要表现是基底动脉内皮细胞间紧密连接消失，胞膜部分或完全脱落，胞质内线粒体肿胀、嵴紊乱、溶解呈空泡，致密颗粒增多，细胞核内染色质边集、浓缩，异染色质增多；平滑肌细胞变形、核扭曲、染色质不均匀，肌丝排列疏松紊乱，出现断裂或溶解，胞浆内可见大量空泡形成，线粒体增多、肿胀、嵴紊乱或溶解；血管外膜神经纤维肿胀、结构模糊。光镜下基底动脉的结构变化趋势与电镜下基底动脉的结构变化趋势相类似，均在SAH后1h时可发现结构的微小改变，从第3天开始明显的结构改变，在第5天至第7天结构变化最明显。结论SAH后脑血管的超微结构会发生损害，并在病程发展中呈明显的动态改变；血管内皮细胞的损害是导致迟发性CVS的重要因素之一。

The ultrastructural pathological characteristics and dynamic changes of brain vessel after subarachnoid hemorrhage in experimental rabbits

Objective To discuss the ultrastructural pathological characteristics and dynamic changes of brain vessel after subarachnoid hemorrhage(SAH),and the mechanism of these changes in delayed cerebral vasospasm.Methods SAH model was made by infusing blood twice into the cistern magna of Japanese rabbits.The animals were divided randomly into SAH group,saline group,puncture group and blank group,at 1 h,3 d,5 d,7 d and 10 d after the first infusion the animals were perfused and basilar artery was harvested.Ultrastructural changes were observed under light microscope and electron microscope.Results Under the light microscope,the vessel wall became thick,the vessel cavity became narrow,the endothelia cells became swollen,vacuoles could be found in the chromatin,inner elastic membrane became reductus and broke.Under the electron microscope,the close connection between the endothelial cells disappeared,the membrane of the cells fell off,and the mitochondria became swollen,vacuoles could be seen,the chromatin became concentrated,heterochromatin could be seen,smooth muscle became deformed,chromatin became uneven, myofilament had derangement and fragmentation and dissolved,vacuolus could be seen in the kytoplasm,mitochondrion became swollen.The structural change of basilar artery under the light microscope got similar to that under the electron microscope;slight change was observed right after 1 h of SAH,significant change was observed at 3 d,and most obvious change was observed between 5 d and 7 d.Conclusion Ultrastructural changes were observed in the basilar artery after SAH,and significant dynamic changes were observed in the progress.The damage of endothelia cells may be the important factors which cause delayed cerebral vasospasm.