神经生长因子对大鼠脊髓损伤后一氧化氮合成酶含量的影响

Effeets of nerve growth factor on NOS after spinal cord injury in rats

探讨神经生长因子（ＮＧＦ）对脊髓损伤保护作用的机制。方法采用Ａｌｉｅｎ’ｓ法以２５ｇｃｍ致伤大鼠Ｔ８脊髓，经蛛网膜下腔导管分别于术后即刻、３０分钟、１、２、３、４、８、１２、２４小时各注入ＮＧＦ溶液，并与生理盐水组和正常对照组作对照。采用放射强度测定法测定一氧化氮合成酶（ＮＯＳ）含量。结果与正常组相比较，ＮＯＳ含量在伤后１０分钟、１、２、４、８小时均显著升高（Ｐ＜０．０１），ＮＧＦ治疗组与生理盐水组相比较，在伤后１０分钟、１、２、４、８小时ＮＯＳ活性明显下降（Ｐ＜０．０１）。结论ＮＧＦ通过抑制脊髓损伤后ＮＯＳ的升高效应，抑制了一氧化氮（ＮＯ）的神经毒性作用，从而保护了神经组织。

Objective To investigate the protective mechanisms of nerve growth factor (NGF)on spinal cord injury. Method The spinal cord injury (SCI) of Wistar rats was performed by a 10g×2.5 cm impact on the posterior TS spinal cord. The experimental animals received NGF liquid by subarachnoids space tube. The content of nitric oxide synthase (NOS) were determined by radioactive way.Result NOS activity was significantly increased 8 h after the injury as compared with that in controlgroup (P<0.01). The level of NOS in NGF group were obviously lowered as compared with that innormal saline group & h after the injury (P<0. 01). Conclusion NGF can protect spinal cord againstinjury in vivo. One of mechanisms is that NGF prohibits neurotoxicity of the nitric oxide.