Murashima Y L, Yoshii M, Suzuki J
Department of Neurophysiology, Tokyo Institute of Psychiatry, Japan.
Epilepsia. 2000;41 Suppl 6:S195-9. doi: 10.1111/j.1528-1157.2000.tb01581.x.
To understand the role of nitric oxide (NO) in the regulation of seizures, we measured the extracellular levels of the NO metabolites nitrite and nitrate as indices of NO generation in the parietal cortex, hippocampus, and temporal cortex of EL mice. Furthermore, alterations of neuronal, endothelial, and inducible nitric oxide synthetase (nNOS, eNOS, and iNOS, respectively) were observed to correlate them with epileptogenesis.
EL mice of 20 weeks and 30 weeks of age (before and after the establishment of epileptogenesis, respectively) were used. Nitrite was quantified using the specific absorbancy of diazo dye. NOS isoenzymes (nNOS, iNOS, and eNOS) were also investigated in the hippocampus during development until mice were 30 weeks old. Samples (total protein, 8.33 to 8.43 microg) were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and identified by immunoblotting.
EL mice that experienced repetitive seizures showed a remarkable increase in nitrite in the hippocampus at 30 weeks of age compared with EL mice that had no experience of seizures. nNOS and iNOS were major and minor components, respectively, and both increased in parallel with the development of epileptogenesis. eNOS was not detectable.
Excess iNOS (and subsequent increase in harmful NO) and deficient eNOS (and subsequent decrease in NO identified as an endothelium-derived relaxing factor) may work together to form a focus complex.
为了解一氧化氮（NO）在癫痫发作调控中的作用，我们测量了EL小鼠顶叶皮质、海马体和颞叶皮质中NO代谢产物亚硝酸盐和硝酸盐的细胞外水平，以此作为NO生成的指标。此外，观察了神经元型、内皮型和诱导型一氧化氮合酶（分别为nNOS、eNOS和iNOS）的变化，以将它们与癫痫发生相关联。
使用20周龄和30周龄的EL小鼠（分别在癫痫发生确立之前和之后）。利用重氮染料的特异性吸光度对亚硝酸盐进行定量。在发育至30周龄的小鼠海马体中也研究了NOS同工酶（nNOS、iNOS和eNOS）。样品（总蛋白，8.33至8.43微克）通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分离，并通过免疫印迹进行鉴定。
与未经历癫痫发作的EL小鼠相比，经历重复性癫痫发作的30周龄EL小鼠海马体中的亚硝酸盐显著增加。nNOS和iNOS分别是主要和次要成分，两者均随着癫痫发生的发展而平行增加。未检测到eNOS。
过量的iNOS（以及随后有害NO的增加）和缺乏的eNOS（以及随后被鉴定为内皮源性舒张因子的NO的减少）可能共同作用形成一个焦点复合体。
