Kvβ1.3亚基显著影响DPO-1对表达在卵母细胞上的Kv1.5通道的阻断作用  

Kvβ1.3 accessory subunit affects block of Kv1.5 potassium channel by DPO-1 in Xenopus oocytes significantly

作　　者：赵宁[1] 杜以梅[1] 夏程琨[2] 高明[1] 邹安若[1] 廖玉华[1] 

机构地区：[1]华中科技大学协和医院心内科离子通道病研究中心,武汉430022 [2]华中科技大学协和医院心外科,武汉430022

出　　处：《临床心血管病杂志》2010年第3期171-174,共4页Journal of Clinical Cardiology

基　　金：国家重点基础研究发展计划(973计划)资助(项目编号2007CB512000;课题编号2007CB512005);国家自然科学基金(No:30971243)

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。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.

关 键 词：Kvβ1·3亚基 DPO-1 卵母细胞 Kv1·5通道 

分 类 号：R541.7[医药卫生—心血管疾病]