胺碘酮对Kv1.3通道电流的阻断和体外激活T淋巴细胞表型的影响研究

目的:研究胺碘酮对体外表达的Kv1.3通道的作用及对体外激活的CD3+CD4+和CD3+CD8+T淋巴细胞的作用,以阐明胺碘酮免疫调节的可能机制之一。方法:使用双电极电压钳技术记录表达于非洲爪蟾卵母细胞的Kv1.3钾通道电流,并观察胺碘酮对电流的影响。取分离的人外周血淋巴细胞分为正常未激活组、离子霉素和佛波酯激活组、激活后胺碘酮处理组,双抗体标记后流式细胞仪测定CD3+CD4+和CD3+CD8+相应比例。结果:胺碘酮可浓度依赖性阻断Kv1.3通道,阻断的半数有效浓度为3.43μmmol·L-1,阻断作用具有电压非依赖性;与正常未激活组比较,激活组CD3+CD4+/CD3+CD8+值无显著性差异(P>0.05)。与激活组比较,激活后胺碘酮处理组CD3+CD4+/CD3+CD8+值显著降低(P<0.01)。结论:胺碘酮阻断失活状态的Kv1.3通道,可能是其发挥调节免疫功能的机制之一。

Effect of Amiodarone on Blockage of Kv1.3 Channels and Expression of Phenotypic Distribution of Activated T Lymphocyte in Vitro

OBJECTIVE： To explore the possible mechanism of the immunomodulation action of amiodarone through investigating amiodarone＇ s blockade action on Kv1.3 channels and modulation effect on phenotypic distribution of activated CD3^＋CD4^＋ and CD3 ^＋CD8^＋ T lymphocyte in vitro. METHODS： The standard two-microelectrode voltage clamp techniques was applied to record the Kv1.3 potassium channel current expressed in xenopus oocytes and the blocking effect of amiodarone on Kv1.3 channels was observed. The isolated human peripheral blood lymphocytes were divided into normal nonactivated group, activated group stimulated by Ionomycin and PMA, and activated amiodarone-treated group. The ratio of CD3 ^＋CD4^ ＋ to CD3^ ＋CD8^＋ T lymphocyte was measured with flow cytometer after double- antibody labeling. RESULTS： Amiodarone showed a concentration- dependent inhibition effect on Kv1.3 channels current and the ICs0 was 3.43 μmmol ·L^-1. The blockade was voltage- independent. The ratio of CD3^ ＋CD4^＋ to CD3^＋CD8^＋ in activated control group had no significant difference compared with the normal non-activated group（P 〉 0.05）; while the ratio of CD3^ ＋CD4^ ＋ to CD3^ ＋CD8^ ＋ in activated amiodarone-treated group was significantly lower than in activated control group（P〈0.01） . CONCLUSION： Amiodarone blocking inactivated-state Kv1.3 channels is possibly one of mechanisms accountable for its immunomodulatory effect.