周围神经适应缓慢牵伸的机制研究——兔胫后神经血-神经屏障及束膜屏障观察

A study on the adaptive mechanism of peripheral nerve to gradual limb lengthening:observation on the perineurial barrier and vascular permeability

目的观察缓慢牵伸胫骨延长对兔胫后神经束膜屏障及毛细血管屏障的影响。方法取兔胫骨延长 10％、 20％、 30％及 40％的四组动物各 4只行胫后神经电镜观察，再各取 4只行束膜屏障及毛细血管屏障测试。结果随着肢体延长幅度增加，神经束膜变薄、平直，束膜内线粒体增多，并出现大量空泡，但束膜的连续性始终保持完整，束内毛细血管连接紧密，血－神经及束膜屏障完好。结论与急性牵伸不同，缓慢牵伸过程中，神经的屏障功能始终完整，为神经的再生修复提供了良好的微环境。

Objective To evaluate the effect of limb lengthening on the perineurial barrier and vascular permeability of peripheral nerve. Methods Thirty-two rabbits with limb lengthening of 10％ , 20％ , 30％ and 40％ were used in this study; 8 animals were allocated in each group. Sixteen were employed for the electron microscopic(EM) observation and the others for the investigation of perineurial barrier and vascular permeability of the tibial nerves. Results Even if the elongation reached 40％ of the original length of the tibia, both the perineurium and inner membrane of capillary was still intact, the perineurial barrier and vascular permeability maintained normal; however, EM examination revealed increase of a large number of vacuoles and the increase of the number of mitochondria in the cell of the perineurial membrane. Conclusion It is the gradual limb lengthing of < 1 mm per day that keeps normal perineurial barrier and vascular permeability, which helps to preserve a constant and favorable introfascicular micro environment for nerve regeneration.