红藻氨酸诱导癫痫发作小鼠脑组织中 NO_2^- 与硫代巴比妥酸反应物浓度测定

Colorimetric determination of concentration of nitrite and thiobarbituric acid reactive substances in mouse brain during kainic acid induced seizures

了解活性介质一氧化氮（ＮＯ）与癫痫发作的关系。方法用比色法检测红藻氨酸（ＫＡ）诱导ＢＡＬＢ／ｃ小鼠癫痫发作后，不同时点脑匀浆上清液中亚硝酸根（ＮＯ２－）与硫代巴比妥酸（ＴＢＡ）反应物的含量。结果ＮＯ２－浓度与ＴＢＡ反应物含量的多少与ＫＡ诱导的癫痫发作时程有关。在发作初期，ＮＯ２－随发作持续而增多，但发作后期又迅速减少。ＮＯ２－浓度的升高与减低受Ｌ－精氨酸（Ｌ－Ａｒｇ）及其硝基衍生物ＮＧ位硝基左型精氨酸（Ｌ－ＮＮＡ）的影响。同时对ＮＯ２－检测标本做ＴＢＡ反应物检测，发现ＮＯ２－的减少与ＴＢＡ反应物增多相关，在癫痫发作初期ＴＢＡ反应物含量较低，但随着发作时间的延长明显增多，ＴＢＡ含量的变化同样可受Ｌ－Ａｒｇ与Ｌ－ＮＮＡ的影响。结论Ｌ－Ａｒｇ－ＮＯ途径可能参与了癫痫发作的起动、传播和继发性脑损害的全过程，在发作后期，过量生成的ＮＯ可能有神经兴奋毒性作用。

Objective The study was to explore the implication of nitric oxide (NO) pathway in epilepsy.Methods The concentrations of the nitrite (NO 2 -) and thiobarbituric acid reactive substances (TBARSs) in the brain homogenate of BALB/c mice were determined with the colorimetric methods. Results Both the production of NO 2 - and TBARSs were related to the different stages of epileptic seizures induced by kainic acid (KA). NO 2 - was highly increased but TBARSs were kept at low levels at the early seizure stage ( P <0.01). Along with the seizure lasting, NO 2 - decreased but TBARSs increased rapidly ( P <0.01). The concentration variations of both NO 2 - and TBARSs were influenced by L arginine ( P <0.01) and N G nitro L arginine ( P <0.05). Conclusion The L Arg NO pathway was definitely involved in the KA seizure. During the epileptic seizures, NO might firstly act as a homeostasis agent and thereafter it might insult the brain.