中文摘要：

目的：研究Kvβ1.3亚基和Kv1.5共表达时,对表达在非洲爪蟾卵母细胞的Kv1.5通道DPO-1的阻断作用的影响。方法：在非洲爪蟾卵母细胞上异源表达克隆Kv1.5及Kvβ1.3通道基因,用双电极电压钳技术记录全细胞电流,检测药物对Kv1.5通道及Kv1.5＋Kvβ1.3共表达通道电流的影响。结果：DPO-1以电压、频率及浓度依赖方式抑制Kv1.5＋Kvβ1.3共表达通道的电流。Kvβ1.3亚基存在时,DPO-1的阻断效应明显减弱,DPO-1阻断的IC50由（0.77士0.12）μmol/L显著增加至（47.21士5.18）μmol/L,增加了约60倍（P〈0.01）。结论：Kvβ1.3亚基显著抑制DPO-1对表达在卵母细胞上的Kv1.5通道的阻断作用,但不改变其电压、频率及浓度依赖性,可能机制是Kvβ1.3亚基与DPO-1相互竞争Kv1.5孔区内部的某些结合位点。

英文摘要：

Objective：To investigate the effects of Kvβ1.3 subnuit on block of Kv1.5 potassium channel by DPO-1 in Xenopus oocytes.Method：Kv1.5 and Kvβ1.3 cRNA channel gene were expressed in Xenopus oocytes and channel currents were recorded using standard two-microelectrode voltage clamp techniques in control condition or DPO-1 intervention.Result：DPO-1 inhibited Kv1.5＋Kvβ1.3 coexpressing channel in a voltage-,frequency-and concentration-dependent manner.The block efficacy of Kv1.5 potassium channel was diminished significantly in the presence of Kvβ1.3 subunit.The IC50 was increased remarkably from（0.77士0.12）μmol/L to（47.21士5.18）μmol/L,about 60 folds（P0.01）.Conclusion：Kvβ1.3 accessory subunit inhibited DPO-1 block of Kv1.5 potassium channel expressed in Xenopus oocytes significantly,but did not change its voltage-,frequency-and concentration-dependent manner.This effect may concern with the competition between Kvβ1.3 subunit and DPO-1 for the residues in the pore of the Kv1.5 potassium channel.