Pacemaker current in single cells and in aggregates of cells dissociated from the embryonic chick heart.
Pacemaker current in single cells and in aggregates of cells dissociated from the embryonic chick heart.
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单细胞和从胚胎鸡心脏分离的细胞聚集体中的起搏器电流。
DOI：
10.1113/jphysiol.1992.sp019276
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
A. Shrier
中科院分区：
文献类型：
--
作者：
R. Brochu;J. Clay;A. Shrier
1. 我们用全细胞膜片钳技术测量了从小鸡胚胎心脏分离的单个细胞或两个或三个细胞组成的小细胞簇的起搏器电流I(f)，用双微电极电压钳技术测量了分离细胞的多细胞重聚集体的起搏器电流I(f)。2. 我们观察到来自心室细胞聚集体的时间依赖性电流（I(f)）在- 90至- 60 mV范围内，正如我们之前从该制备中获得的结果一样，我们之前将其归因于钾离子电流机制IK2。我们还在单个心房细胞和心房细胞群中观察到I(f)。3. 心房制剂中I(f)的激活范围为- 120至- 90 mV（单细胞或聚集体）。心室细胞中I(f)的激活范围也为- 120至- 90 mV，与心室细胞聚集的I(f)激活范围负约30 mV。心室准备中I(f)移位的原因尚不清楚。4. 在胚胎发育的第一周，在心室心脏细胞聚集中观察到的I(f)成分明显是自发起搏器去极化的基础。然而，I(f)并不是心房制剂自发活动的重要因素。这些细胞中的起搏器电流是一个净向内背景分量，其振幅随着发育而显著降低，心室中的I(f)分量也是如此。
1. We have measured the time‐dependent pacemaker current, I(f), in single cells, or small clusters of two or three cells dissociated from embryonic chick hearts with the whole‐cell patch clamp technique, and in multicellular reaggregates of dissociated cells with the two‐microelectrode voltage clamp technique. 2. We observed time‐dependent current (I(f)) in the ‐90 to ‐60 mV range from aggregates of ventricular cells, as in our earlier results from this preparation, which we previously attributed to the potassium ion current mechanism, IK2. We also observed I(f) in single atrial cells and aggregates of atrial cells. 3. The range of activation of I(f) was ‐120 to ‐90 mV in atrial preparations (either single cells or aggregates). The activation range of I(f) in ventricular cells was also ‐120 to ‐90 mV which is approximately 30 mV negative to the I(f) activation range in ventricular cell aggregates. The reasons for this shift of I(f) in ventricular preparations are unknown. 4. The I(f) component clearly underlies the spontaneous pacemaker depolarization which is observed in ventricular heart cell aggregates during the first week of embryonic development. However, I(f) is not a significant factor underlying spontaneous activity in atrial preparations. The pacemaker current in these cells is a net inward background component, which is significantly reduced in amplitude with development, as is the I(f) component in the ventricle.
DOI：
10.1113/jphysiol.1983.sp014691
发表时间：
1983
期刊：
The Journal of physiology
影响因子：
--
作者：
Cohen,IS;Falk,RT;Mulrine,NK
通讯作者：
Mulrine,NK