次声作用后鼠脑超微结构与血脑屏障改变

Changes of cerebral utrastructure and blood brain barrier permeability after infrasound damage

目的 探讨次声作用后脑超微结构与血脑屏障(bloodbrainbarrier,BBB)通透性改变及意义。方法 40只SD大鼠随机分为正常对照、次声作用1次、7次及14次四组。采用本校研制的次声压力仓。次声作用组用8Hz、120dB的次声按规定次数,每次作用2h。硝酸镧心脏灌注法固定鼠脑,透射电镜下观察脑超微结构与BBB改变。结果 随次声作用次数增加,脑超微结构损害愈重;BBB改变,次声作用1次与7次组相似,均有紧密连接开放,血管基膜外以至组织间隙内存在硝酸镧颗粒;至14次组愈加严重,可见大量硝酸镧颗粒经BBB进入组织间隙,与1、7次两组比较差异有显著性(P<0.05)。结论 次声作用可直接破坏脑超微结构与BBB;在相同强度的次声作用下,作用次数的多少与BBB及脑损害程度直接相关。

Objective To study the changes and significance of cerebral ultrastructure and blood brain barrier(BBB) permeability after infrasound damage to the rats so as to probe into the mechanism of infrasonic biologic effects.Methods 40 SD rats were randomized into four groups control, infrasound damage 1 time, 7 times and 14 times,8 Hz,120 dB infrasound was applied to infrasonic damage groups for 2 h once according to the planned schedule. Lanthanum nitrate blending liquid was used for the brain fixation through heart. Under electronic microscope the changes of cerebral ultrastructure and BBB permeability were observed.Results With increase in the times of infrasonic damage, cerebral ultrastructure became more aggravated. 1 and 7 time group shared the same changes of BBB permeability in which close junction opened and Lanthanum nitrate particles passed BBB into the brain tissue. Compared with that of 1 and 7 time group,14 time group had more radical changes in which a great deal of Lanthanum nitrate particles exist ed in the brain tissue(P< 0.05 ).Conclusion Infrasound can directly damage the function and structure of cerebral ultrastructure and BBB.In the same degree, the extent of brain damage was closely related to the times of infrasonic injury. It is suggested that infrasound plays a pivotal role in brain damage through increasing BBB permeability and brain injury.