光化学局灶性颈髓缺血损伤诱导大鼠NOS的表达

Expression of NOS after phochemically induced focus cervical spinal cord ischemia in rats

目的 :建立局灶性颈髓缺血损伤大鼠模型及探讨NOS表达在损伤中的作用机制 .方法 :95只SD大鼠分成两大组 :①对照组 2 0只 ;②实验组 75只 .实验组按照射时间分成5 ,1 0和 1 5min 3小组 ,每小组又按存活时间分为 1 ,3,7,1 4和 2 1d 5组 .应用光化学方法制造局灶性颈髓缺血损伤 ,用改良Menzies法评价大鼠行为学 ,以及应用NADPH染色和中性红复染技术 ,观察大鼠行为学改变 ,颈髓组织学改变 ,以及NOS表达的变化 .结果 :对照组及 5min组未见病灶及行为异常 ,可见后角及中央导水管周围少量NOS样阳性神经细胞 ;1 0min组可见局部色素沉着 ,神经功能中度缺损 ,可见缺血侧脊髓前角运动神经元及中间带神经元大量NOS样阳性神经元 ,而且有时间依赖性 ,缺血损伤 3d后出现 ,7d达到高峰 ,1 4d减退 ,2 1d基本消失 ;1 5min组可见脊髓组织明显塌陷及空腔形成 ,神经功能重度缺损 ,缺血侧可见少许NOS样阳性神经元 .结论 :光化学颈髓损伤是一种较理想的局灶性颈髓缺血损伤大鼠模型 。

AIM: To study the NOS expression after focal cervical spinal cord ischemia in rats. METHODS: Ninty five SD rats were divided into two large groups: control group ( n =20) and experimental group ( n =75). The latter was divided into three subgroups according to the time of irradiation and each subgroup was further divided into five small groups according to the time points of survival. The model of the cervical spinal cord ischemia was made by photochemical method, the behaviors of the rats by Menzies’ method, the expression of NOS was observed by NADPH d histochemistry, and the histology of cervical spinal cord by counterstaining with neutral red. RESULTS: The focus injury and behavioral abnormity were not found in control group and the 5 minute group. In the 10 minute group, the score of nerve functional loss was moderate, the local pigmentation and a vast amount of NOS like positive neurons were found in the ventral motoneuron and intermediate zone, which were time dependent: Appearing at the third day, peaking in the first week, reducing in the second week and disappearing in the third week. In the 15 minute group, the spinal cord sunk apparently and the score of nerve functional loss was severe, with only a few NOS like positive neurons, which was probably due to necrocytosis and neuron dropping. CONCLUSION: The photochemical method is satisfactory for the establishment of the model of focus cervical spinal cord ischemia in rats. Spinocervical spondylosis may be related to the NOS expression.