大鼠脊髓损伤后神经细胞凋亡及相关调控蛋白Caspase-3表达的时空分布

目的 观察大鼠脊髓损伤（SCI）后神经元细胞凋亡和相关调控蛋白Caspase-3表达的时间、空间分布规律。方法 SD大鼠50只，分为假手术组和SCI组,钳夹法建立SCI模型，用结晶紫（CV）染色法、TUNEL法和免疫组织化学方法观察SCI后6h、12h、24h、3d和7d损伤中心到头端0～5.00mm空间范围内脊髓神经细胞存活、凋亡以及相关调控蛋白Caspase-3的表达状况。 结果 CV染色发现，SCI后6h～7d在0～0.50mm空间范围内均未发现存活的神经细胞，在1.00～3.50mm距离内，存活的神经细胞数逐渐增加，4.00mm处达峰值；TUNEL结果发现，SCI后6h～7d在1.05～4.55mm范围内，神经细胞出现凋亡，3d时在2.55mm处，细胞凋亡达高峰，7d时显著减少；免疫组织化学结果发现，SCI后6h～7d在1.10～4.60mm范围内，神经元细胞出现Caspase-3阳性表达，3d在3.10mm处Caspase-3表达达到高峰，7d显著减少。 结论 SCI后，凋亡的神经细胞及其相关调控蛋白Caspase-3的表达有一定的时空分布规律。

Temporal and spatial expression pattern of apoptosis and its associated protein in neurons after spinal cord injury in rats

Objective The purpose of this study is to evaluate temporal and spatial expression pattern of neuron apoptosis and its associated protein in neurons after spinal cord injury in rats. Methods Fifty SD rats were divided into a sham operated and a spinal cord injury group, 25 rats per group. SCI model was made by clamps methods. The expression profiles were evaluated by counting the cresyl violet-stained surviving cells and the number of TUNEL-positive neurons. Caspase-3 expression was determined by immunohistochemical analysis in sections 0-5.00 mm rostral to the epicenter at 6,12,24 hours, 3 and 7 days after injury. Results Neurons continued to disappear over 7 days after injury and neuronal loss extended to the areas far away from the epicenter over times except 0-0.50mm. TUNEL-positive and Caspase-3 positive neurons in gray matter appeared after 6 hours, gradually increased to a peak level after 3 days at 2.55mm and 3.10mm, and declined by 7 days postinjury in the section 1.10-4.60mm rostral to the epicenter. Conclusion Temporal and spatial distribution of neurons apoptosis and Caspase-3 protein expression after spinal cord injury are regulated.