THE EXPRESSION OF BCL-2, BAX AND CASPASE-3 IN NEURON OF THE SPINAL CORD ANTERIOR HORN AFTER CAUDA EQUINA ACUTE COMPRESSION

Objective To explore the influence of the acute cauda equina compression on the iumbosacral spinal cord; To clarify the pathologic change of the motor neuron after acute cauda equina compression. Methods 27 canis familiaris were randomly divided into 9 groups （3 in each） ： one for normal group, one for control group, and seven for compression groups. The control group and compressed groups was given operation and the sac made of silica gel was placed under the lamina of L5-6. Water was injected into the sac until their posterior legs paralysis in compressed groups, the animals had been compressed for 4, 8, 12, 24, 48, 72, 168 hours. The control group were not injected water. Cells apoptosis was investigated with the technology of TdT-mediated biotin dUTP nick end-labeling （TUNEL） staining. The Bcl-2 Bax and Caspase-3 protein was investigated by immunohistochemical method. Results TUNEL staining cells in anterior horn presented after compressed 8-12 hours, and at 72 hours the number of positive cells got to maximum, it decreased subsequently after 168 hours. The protein of Bax, Bcl-2 expressed a little in normal motor neuron. The caspase-3 protein didn＇t express in normal ceil. They all reached the peak at 72 hours after compression. Conclusion The apoptosis of motor neuron occurred earlier after eauda equina acute compression. Bax protein restrained Bcl-2 protein then active caspase-3 and conduced apoptosis of motor neuron.     

家犬腰椎牵拉损伤引起马尾神经功能改变的实验研究

设计了椎间松解及椎体外固定器固定的动物模型 ,通过调整外固定器长度 ,造成椎管内马尾神经牵拉损伤。当外固定器长度增大 2 cm时 ,马尾诱发电位( CESEP)的 N2 波幅度降低。动物清醒后出现 :1后肢运动与感觉障碍 ,神经功能评分明显降低。随牵拉强度增加 ,N2 波幅度逐渐降低并伴 CESEP图形畸变 ,直至最终消失。 2双后肢运动及痛觉丧失。神经功能评分减至 0分。故通过调整外固定器长度 ,可动态改变脊柱牵拉损伤程度 ,损伤程度与 CESEP及动物神经功能评分一致。该模型还有可排除 SEP假阴性或假阳性之突出优点。     

Apoptosis of lumbar spinal cord neurons in cauda equina syndrome rats

Objective To explore the law of apoptosis of lumbar spinal cord neurons in cauda equina syndrome (CES). Methods Cauda equina of rats was compressed by a piece of silica gel stick. From day 1 to day 28, the lumbar spinal cord specimens were harvested and assessed by Nissl's staining and TUNEL staining. Results Compression of cauda equina caused lesion and apoptosis of neurons in lumbar spinal cord, and the extent of apoptosis reached the peak on 7th day after compression. Conclusion Apoptosis of neurons in lumbar spinal cord might be one of the reasons why patients with CES get poor prognosis.