Linear electrical properties of passive and active currents in spherical heart cell clusters.
Linear electrical properties of passive and active currents in spherical heart cell clusters.
复制标题
球形心脏细胞簇中被动和主动电流的线性电特性。
DOI：
10.1016/s0006-3495(81)84725-x
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发表时间：
1981
影响因子：
3.4
通讯作者：
Johnson,EA
中科院分区：
文献类型：
--
作者：
Mathias,RT;Ebihara,L;Lieberman,M;Johnson,EA
对组织培养中生长的胚胎鸡心脏细胞的小球形簇进行阻抗研究。每个合胞体簇都被两个微电极刺穿；一个注入低幅度随机电流，另一个记录由此产生的细胞内电位扰动。将电流和电位记录数字化，分解为其正弦分量，并确定簇的频域阻抗。将阻抗数据与球形合胞体中的电流理论进行比较，并导出描述组织膜和细胞间裂的参数值。这些簇会自发活动，但当被两个电极刺穿时通常会暂时静止。电位稳定在接近-30 mV 的值。在这种去极化电位下，可能存在于心脏动作电位中的主动慢电流对线性阻抗有显着贡献，在 1-3 Hz 频率下产生阻抗幅度的谐振峰值。这些电流的线性阻抗函数在河豚毒素 (TTX) 和 D-600 存在和不存在的情况下进行表征。 TTX 对阻抗没有明显影响，但 D-600 基本上消除了有功电流。尽管这些电流的离子基础尚不清楚，但频域分析似乎是研究心肌慢电流的可行技术。
Impedance studies were performed on small spherical clusters of embryonic chick heart cells grown in tissue culture. Each syncytial cluster was impaled with two microelectrodes; one injected low amplitude stochastic current and the other recorded the resulting perturbation of intracellular potential. The current and potential records were digitized, decomposed into their sinusoidal components, and the frequency domain impedance of the cluster was determined. The impedance data were compared with a theory for current flow in a spherical syncytium and values were derived for parameters describing the membranes and intercellular clefts of the tissue. The clusters were spontaneously active but usually became temporarily quiescent when impaled with two electrodes. The potential stabilized at a value close to -30 mV. At this depolarized potential, active slow currents, presumably present in the cardiac action potential, contributed noticeably to the linear impedance, producing a resonant peak in the magnitude of the impedance at a frequency of 1–3 Hz. The linearized impedance functions for these currents were characterized in the presence and absence of tetrodotoxin (TTX) and D-600. TTX had no noticeable effect on the impedance but D-600 essentially abolished the active currents. Although the ionic basis of these currents is not known, frequency domain analysis appears to be a viable technique for studying slow currents in heart muscle.