大鼠实验性变态反应性脑脊髓炎中一氧化氮的变化

目的　观察外周和中枢一氧化氮 (NO)在大鼠实验性变态反应性脑脊髓炎 (EAE)中的动态变化 ,探讨EAE大鼠发病的相关生物学机制。方法　 采用免疫组化法和硝酸还原酶法 ,观察豚鼠全脊髓匀浆诱导的Wistar大鼠EAE的过程中 ,脊髓内表达iNOS胶质细胞与外周NO代谢物NO 2 和NO 3的变化。 结果　 对照组脊髓内未发现表达iNOS阳性细胞 ,表达iNOS的CNS胶质细胞可能是小胶质细胞 ,而且它的变化与EAE大鼠的病情一致 ,评分 2分和 3分EAE大鼠脊髓表达iNOS的小胶质细胞比评分 1分大鼠明显增多 (P <0 .0 1) ,恢复期EAE大鼠表达iNOS的小胶质细胞明显减少 (P <0 .0 1)。EAE大鼠外周血清NO值随症状程度加重而升高 ,但在EAE恢复期时仍保持较高水平。未发病大鼠血清NO值明显增高 ,与对照组之间具有显著性差异 (P <0 .0 1)。 结论　 小胶质细胞产生的NO可能在急性期EAE大鼠的发病中起重要作用

Kinetic changes of nitric oxide in experimental allergic encephalomyelitis in rats

Objective To observe the kinetic changes of nitric oxide in experimental allergic encephalomyelitis (EAE) in rats, and to explore the mechanism of EAE. Methods EAE was induced by guinea pig spinal cord homogenate (GPSCH) and the expression of iNOS in cords was examined by using polyclonal antibody to iNOS with the method of immunohistochemistry, and nitric oxide in plasma were examined by nitric acid redox at various stages. Results In control group, there was no iNOS-positive cell detected in cords. The glia expressing iNOS in CNS was activated microglia, the number of microglia expressing iNOS paralleled with the process of EAE rats, in score 2 or 3 rats , the amount of microglia expressing iNOS was greater than in score 1 rats( P <0.001). In rats at recovery stage, the number of positive cell was less than those in score 2 and 3 rats( P <0.001). The level of NO in serum gradually increased with the aggravation of clinical symptom, however, the level of serum NO remained elevated at recovery stage. The level of serum NO in rats without neurological signs were more significant elevated than in control group( P <0.001). Conclusion NO produced by the microglia cells might play a role during acute stage of EAE in rats.