大鼠机械性脑干损伤早期延脑网状结构的超微病理研究

Ultrastructural studies on reticular formation of medulla oblongata in the early stage of brain stem mechanical injury in rats.

目的 探讨脑干损伤早期延脑网状结构的超微病理变化。方法 将实验大鼠分为创伤组和对照组，透射电镜观察大鼠机械性脑干损伤早期（１０ｍｉｎ，０ ．５ｈ，１ｈ ，３ｈ） 延脑网状结构的超微病理变化。结果 脑干损伤１０ｍｉｎ 即可见神经微丝（ｎｅｕｒｏｆｉｌａｍｅｎｔ， ＮＦ） 排列紊乱、疏密不均，ＮＦ 臂的缺失，髓鞘层面分离，轴膜内皱，与髓鞘间形成空隙，微血管周围基质密度降低以及线粒体肿胀等超微病变。脑干伤后存活时间延长，上述病变更为显著。本文就上述超微病变的形成机制及病理学意义进行了探讨。结论 脑干机械性损伤能够明显引起延脑网状结构的超微病理学变化。

Objective To study the ultrastructural changes of reticular formation of medulla oblongata following the early stage of brain stem mechanical injury in rats. Methods Experimental rats were divided into trauma and control groups. Samples of brain stem in two groups were collected at post trauma of 10min, 30min, 60min and 180min. The reticular formation of medulla oblongata were ultrastructurally observed by transmission electron microscopy. Results In control group, neurofilament (NF) was regularly arranged with relative space of NF side arms, myelin sheath showed normally laminar shape. In trauma group, NF was irregularly and loosely arranged, (lose of NF side arm) was often seen. Most of laminas of myelin sheath were separated so that forming intra myelinic space. Swollen mitochondria was frequently found, degenerated capillary with low density of matrix were observed. These pathological changes can demonstrate as early as 10min of post trauma, the severity of pathological changes in brain stem were more prominent with prolonging survival intervals. Conclusion Mechanical injury of brainstem can induce obviously pathological changes in reticular formation of medulla oblongata in the early stage, which could increase susceptibility to rapid individual death and immunohistochemical stain.