目的探讨钾离子通道Kv4.2、KV4.3及其相互作用蛋白KChIP1在杏仁核电点燃模型中的表达变化及可能的作用。方法刺激SD大鼠右侧杏仁核7d以建立电点燃模型,提取杏仁核总RNA进行RT—PCR。研究致痫后KChIP1、Kv4.2和Kv4.3在mRNA水平表达变化;同时提取杏仁核全细胞蛋白进行Western印迹,观察KChIP1和Kv4.2在蛋白水平表达变化。结果在mRNA表达水平,双侧杏仁核KChIP1在模型组[包括Racine分级的高发作级别组(47.0±3.6)和低发作级别组(41.3±10.2)]明显高于假手术组(20.0±10.6)(P高=0.000,P低=0.001),Kv4.2和Kv4.3在模型组亦升高,在高发作级别组有升高更明显倾向。双侧KChIP1和Kv4.2的蛋白表达水平变化与mRNA表达变化相似。各组点燃刺激侧与非刺激侧相比mRNA及蛋白表达差异均无统计学意义。结论Kv4.2、Kv4.3及KChIP1在电点燃癫痫模型双侧杏仁核都有不同程度的升高(KChIP1升高更明显。Kv4.2和Kv4.3的变化在发作级别高时升高较明显),这提示钾通道的改变不是癫痫灶点燃的原因,而可能是机体对发作的保护性反应。
Objective To investigate the changes of the potassium channels voltage gated potassium channel (Kv) 4. 2, Kv4. 3, and Kv interacting protein 1 ( KChIP1 ) during the process of amygdala kindling epilepsy and possible role thereof. Methods Thirty-two SD rats were randomly divided into sham operation group (n = 12, receiving the implantation of bipolar electrode into the right amygdala only), and kindling model group which was re-divided into 2 subgroups: low grade seizure subgroup ( n = 8, undergoing stimulation 40 times a day for 7 days so as to induce seizure of stage 1 - 3 according to Racine grading) and high grade seizure subgroup ( n = 2, undergoing stimulation 40 times a day for 7 days so as to induce seizure of stage 4 - 5 ) The rats were killed in 7 days and their bilateral amygdalae were taken out. RT-PCR was used to examine the mRNA expression of Kv 4. 2, Kv4. 3, and KChIP1 and Western blotting was used to detect the protein expression of Kv 4. 2, Kv4. 3, and KChIP1. Result The mRNA expression of KChIP1 in the high and low grade seizure subgroups were ( 47.0 ± 3.6 ) and ( 41.3 ± 10. 2 ) respectively, both significantly higher than that of the sham operation controls ( 20. 0 ± 10. 6) ( Ph = 0. 000 and P1 = 0. 001 ). The expression levels of Kv4.2 and Kv4. 3 of the 2 kindling epilepsy subgroups were also both significantly higher compared with the sham operation controls. No significant differences were found in the mRNA and protein expression of Kv 4. 2, Kv4. 3, and KChIP1 between left and right amygdalae in any groups. Condnsion Changes of Kv4. 2, KV4. 3 and KChIP1 are not the causes of kindling of the epileptic foci. The increased levels of Kv4. 2, KV4. 3, and KChIP1 are more likely to be a protective reaction to seizures.