[Changes of potassium channels Kv4.2, Kv4.3 and Kv channel interacting protein 1 in amygdala kindling epilepsy: experiment with rats].

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 approximately 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 approximately 5) The rats were killed in 7 days and their bilateral amygdala 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) (P(h) = 0.000 and P(l) = 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 amygdala in any groups. CONCLUSION: 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.