Kainic acid (KA) induced epileptic seizures in mice is a commonly used experimental model of epilepsy. Previous studies have suggested the roles of various neurotransmitters and oxidative stress in KA-induced seizures. An important role of hypothyroidism has also been suggested in epilepsy. Thiamazole (TZ) is an anti-hyperthyroid drug with antioxidant property. This study reports the effect of TZ on KA-induced epileptic seizures in mice, produced by intraperitoneal (IP) injection of KA (18 mg/kg). Prior to KA injection, the animals were treated with TZ (12.5, 25 and 50 mg/kg IP). Our results showed that in KA alone group, about half of the animals developed seizures. Pre-treatment of mice with TZ significantly increased the frequency of seizures in dose-dependent manner. Administration of TZ significantly reduced the latency time and aggravated the severity of seizures. TZ also increased the mortality in KA-treated mice. Striatal dopamine and serotonin levels were markedly increased in KA alone treated mice, which were not significantly affected by TZ treatment. Among the indices of oxidative stress, we observed a significant reduction in cerebral vitamin E whereas the levels of cerebral malondialdehyde and conjugated dienes were significantly increased in animals with high severity of seizures. In conclusion, TZ potentiated the frequency and severity of experimental seizure in mice. There is a possibility of altered metabolism of KA in presence of TZ that might have potentiated the toxicity of KA. These findings suggest a caution while administering anti-hyperthyroid drugs in epileptic seizures.

海藻酸（KA）诱导的小鼠癫痫发作是癫痫的一种常用实验模型。先前的研究表明各种神经递质和氧化应激在KA诱发的癫痫发作中的作用。甲状腺功能减退症在癫痫病中也有重要作用。噻唑（TZ）是一种具有抗氧化特性的抗甲状腺功能亢进药物。这项研究报告了TZ对小鼠腹膜内（IP）注射KA（18 mg / kg）产生的KA诱发的癫痫发作的作用。在KA注射之前，用TZ（12.5、25和50mg / kg IP）治疗动物。我们的结果表明，仅KA组，约有一半的动物出现癫痫发作。TZ小鼠的预处理以剂量依赖的方式显着增加了癫痫发作的频率。TZ的使用显着减少了潜伏时间，并加剧了癫痫发作的严重性。TZ还增加了KA治疗小鼠的死亡率。在单独用KA治疗的小鼠中，纹状体多巴胺和5-羟色胺水平显着增加，而TZ治疗对它们没有显着影响。在氧化应激的指标中，我们观察到癫痫严重程度较高的动物中脑维生素E的显着降低，而脑丙二醛和共轭二烯的水平显着增加。总之，TZ增强了小鼠实验性癫痫发作的频率和严重性。存在TZ时，KA的代谢可能发生改变，这可能会增强KA的毒性。这些发现提示在癫痫发作中服用抗甲状腺功能亢进药物时要谨慎。