中文摘要：

目的：探讨蛛网膜下腔注射脂多糖（lipopolysaccharide,LPS）后,肿瘤坏死因子（TNF-α）在脊髓组织内表达水平的动态变化及其在神经细胞内的定位。方法：SD大鼠蛛网膜下腔注射LPS后,采用ELISA法检测大鼠脊髓组织匀浆内TNF-α含量;脊髓组织切片经神经丝（NF）和TNF-α免疫荧光双染色后,在荧光显微镜下观察TNF-α在脊髓神经细胞内的定位。结果：脊髓组织内的TNF-α于蛛网膜下腔注射LPS后1 h开始升高,6 h达到第一个高峰,随后下降,至24 h降至最低但仍高于正常水平,而后又开始上升,在第5天时达到第二个高峰后再逐渐下降,到第14天仍略高于正常水平。结论：脊髓组织内的细胞受LPS刺激后,可产生大量的TNF-α,介导神经组织的炎症反应;脊髓灰质内的神经细胞是LPS的主要靶细胞,可能具有调节脊髓损伤局部炎症反应的生物学功能。

英文摘要：

Objective： To explore the expression of TNF-α in spinal cord after the injection of LPS in subarachnoid cavity. Methods： SD rats were divided into 12 groups. One group served as normal control. The rest received injection of LPS in subarachnoid cavity and were killed respectively at 1 h, 2 h, 4 h, 6 h, 12 h, 24 h, 3 d, 5 d, 7 d, and 14 d. The extract of spinal cord tissue was obtained and assessed with the method of ELISA to define the concentration of TNF-α in different groups. Results： The expression of TNF- α started to increase at the 1 st hour after injection of LPS and reached to the peak at the 6th hour. Then, the level decreased quickly and came to the normal level at the 24th hour. The level increased again on the 3rd day after injection and increased to the second peak on the 5th day. During the 7th to the 14th day after injection, the expression of TNF-α decreased to the normal level step by step. The TNF-α was mainly located in the neurons. Conclusion： After the injection of LPS in subarachnoid cavity, TNF-α may play a pivotal role as an immunomodulatory cytokine in inflammatory reactions.