Heterogeneous expression of repolarizing, voltage-gated K+ currents in adult mouse ventricles
Heterogeneous expression of repolarizing, voltage-gated K+ currents in adult mouse ventricles
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DOI：
10.1113/jphysiol.2004.063347
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发表时间：
2004-08-15
影响因子：
5.5
通讯作者：
Nerbonne, JM
中科院分区：
文献类型：
--
作者：
Brunet, S;Aimond, F;Nerbonne, JM
先前的研究已经证明了四种动力学上不同的电压门控K+（Kv）电流I-to、I-f、I-to、I-s、I-K、I-slow和I-ss在小鼠心室肌细胞中的表达，并且证明了I-to、I-f和I-to、I-s在左心室心尖部和室间隔中的差异表达。在此进行的实验是为了检验以下假设：在成年雄性和雌性（C57 BL 6）小鼠心室中，Kv电流或编码这些电流的Kv亚基（Kv4.2、Kv4.3、KChIP 2、Kv1.5、Kv2.1）的表达存在进一步的区域差异。全细胞电压钳记录显示，平均（+/- S.E.M.）从右心室（RV）分离的细胞的外向钾电流峰值和Ito，f密度显著（P < 0.001）高于左心室（LV）。在左心室内，心尖部细胞外向钾电流峰值和I-to、I-f密度显著高于基底部细胞（P < 0.05）。此外，I-to、I-f和I-K、I-slow密度在从心内膜（Endo）分离的细胞中低于LV壁的心外膜（Epi）表面。重要的是，与LV尖细胞类似，在RV、LV基底、LV外膜或LV内膜肌细胞中未检测到I-to、I-s。成年雄性和雌性小鼠的RV和LV细胞的K+电流密度或特性没有明显的可测量的差异，尽管I-to、I-f、I-to、I-s、I-K、I-slow和I-ss密度显著（P
Previous studies have documented the expression of four kinetically distinct voltage-gated K+ (Kv) currents, I-to,I-f, I-to,I-s, I-K,I-slow and I-ss, in mouse ventricular myocytes and demonstrated that I-to,I-f and I-to,I-s are differentially expressed in the left ventricular apex and the interventricular septum. The experiments here were undertaken to test the hypothesis that there are further regional differences in the expression of Kv currents or the Kv subunits (Kv4.2, Kv4.3, KChIP2, Kv1.5, Kv2.1) encoding these currents in adult male and female (C57BL6) mouse ventricles. Whole-cell voltage-clamp recordings revealed that mean (+/- S.E.M.) peak outward K+ current and Ito,f densities are significantly (P < 0.001) higher in cells isolated from the right (RV) than the left (LV) ventricles. Within the LV, peak outward K+ current and I-to,I-f densities are significantly (P < 0.05) higher in cells from the apex than the base. In addition, I-to,I-f and I-K,I-slow densities are lower in cells isolated from the endocardial (Endo) than the epicardial (Epi) surface of the LV wall. Importantly, similar to LV apex cells, I-to,I-s is not detected in RV, LV base, LV Epi or LV Endo myocytes. No measurable differences in K+ current densities or properties are evident in RV or LV cells from adult male and female mice, although I-to,I-f, I-to,I-s, I-K,I-slow and I-ss densities are significantly (P