Molecular Remodeling of Kv4.3 Potassium Channels in Human Atrial Fibrillation

DOI Web Site Web Site 被引用文献5件

抄録

<jats:p>Repolarizing Potassium Currents in Atrial Fibrillation, <jats:italic>introduction:</jats:italic> Atrial fibrillation (AF) is associated with important alterations in cardiac ion channels that cause shortening and impaired rate adaptation of atrial repolarization. The mechanisms underlying potassium current remodeling in human AF are not clear. We investigated the effects of AF on the gene expression of the Kv4.3, Kv1.4, and Kv1.5 potassium channel subunits and correlated the findings with the transient outward (I<jats:sub>10</jats:sub>) and the sustained outward (I<jats:sub>sus</jats:sub> or I<jats:sub>kur</jats:sub>) potassium current.</jats:p><jats:p> <jats:italic>Methods and Results:</jats:italic> Semiquantitative reverse transcription‐polymerase chain reaction was used to evaluate mRNA expression, and ion currents were studied with the patch clamp technique in right atrial appendages from patients in AF and compared with those from patients in stable sinus rhythm (SR). The presence of AF was associated with a 61% reduction in Kv4.3 mRNA expression (P < 0.001 vs SR), which was paralleled by a reduction in I<jats:sub>to</jats:sub> current densities in this group of patients (i.e., at ± 50 mV: 7.44 ± 0.76 pA/pF in SR and 1.24 ± 0.28 pA/pF in AF; P < 0.001 vs SR). mRNA levels of Kv 1.4 were identical in the two groups. AF did not affect either the gene expression of Kv 1.5 or the current densities of I<jats:sub>sus</jats:sub>.</jats:p><jats:p> <jats:italic>Conclusion:</jats:italic> Chronic AF in humans reduces I<jats:sub>to</jats:sub> by transcriptional down‐regulation of the Kv4.3 potassium channel. Altered gene expression is an important component of the electrical remodeling process and may contribute to repolarization abnormalities in AF.</jats:p>

収録刊行物

被引用文献 (5)*注記

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ