脊髓伤后早期NOS活性变化及其组织细胞来源

Dynamical changes of nitric oxide synthase activity in injured spinal cord tissue after spinal cord injury and its cell derivation

目的：探讨脊髓伤后早期伤段脊髓组织一氧化氮合酶（ＮＯＳ）活性动态变化的规律及其组织细胞来源。方法：检测伤段脊髓组织中３Ｈ标记的精氨酸转化生成３Ｈ－瓜氨酸的量，了解脊髓压迫伤后０～６０ｍｉｎ伤段脊髓组织ＮＯＳ的活性变化；并应用免疫组织化学方法研究其细胞定位。结果：脊髓压迫伤后，ＮＯＳ活性明显增加，伤后５ｍｉｎ达最高点，后又迅速下降，于伤后１ｈ恢复至正常水平。免疫组化可见脊髓灰质中间外侧细胞柱、中央管周围及背角和腹侧角有大量的ＮＯＳ－Ⅰ型阳性细胞，而未见ＮＯＳ－Ⅲ型阳性细胞。结论：在脊髓伤后１ｈ内，伤段脊髓组织ＮＯＳ活性迅速而短暂升高；

Objective: To explore dynamical changes of nitric oxide synthase (NOS) activity in damaged spinal cord tissue at early phase of spinal cord injury and its cell derivation. Methods: NOS activity was determined by the rate of conversion of 3H arginine to 3H citrulline in damaged spinal cord tissue from 0 to 60 min after spinal cord compression, and immunohistochemistry was applied to study NOS derivation. Results: The NOS activity increased sharply after spinal cord compression injury, reached the highest at 5 min, and then decreased rapidly to normal level in 1 h. NOS Ⅰ immunoreactive interneurons were identified mainly in the intermediolateral cell column, around the central canal and in dorsal and ventral horn, but there were no cells with NOS Ⅲ immunoreaction in spinal cord tissue. Conclusion: There is a sharp transient increase in NOS activity during the first hour of spinal cord compression, the derivation is mainly interneurons in spinal cord.