IMPEDANCE ANALYSIS OF A TIGHT EPITHELIUM USING A DISTRIBUTED RESISTANCE MODEL
IMPEDANCE ANALYSIS OF A TIGHT EPITHELIUM USING A DISTRIBUTED RESISTANCE MODEL
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DOI：
10.1016/s0006-3495(79)85250-9
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发表时间：
1979-01-01
影响因子：
3.4
通讯作者：
DIAMOND, JM
中科院分区：
文献类型：
--
作者：
CLAUSEN, C;LEWIS, SA;DIAMOND, JM
本文提出了用交流阻抗法对致密上皮进行等效电路分析的技术，并在家兔膀胱上进行了试验。该方法包括测量跨上皮阻抗和直流分压器的比例与微电极和提取值的电路参数通过计算机拟合的数据的等效电路模型。上皮细胞常用的等效电路模型与阻抗数据存在显著的不匹配，因为这些模型（所谓的集总模型）不正确地表示了与长而窄的空间（如侧向细胞间隙（LIS））相关的分布电阻。一个新的分布式模型的上皮开发考虑到这些结构，从而获得更好的适合的数据。提取的参数包括顶端和基底侧细胞膜的电阻和电容、串联电阻和LIS的横截面积与长度的比率。电容值产生顶侧和基底侧膜的真实的面积的估计。因此，阻抗分析可以独立于EM产生关于活组织的形态信息（LIS的配置和真实的膜区域）。转运调节剂如阿米洛利和制霉菌素的作用可以通过在应用该剂之前和期间从阻抗运行中提取参数值来与它们对特定电路元件的作用相关。通过独立的电生理和形态学测量验证计算的参数值。
Techniques for equivalent circuit analysis of tight epithelia by alternating-current impedance measurements were developed and tested on rabbit urinary bladder. The approach consists of measuring transepithelial impedance and the DC voltage-divider ratio with a microelectrode and extracting values of circuit parameters by computer fit of the data to an equivalent circuit model. The commonly used equivalent circuit models of epithelia give significant misfits to the impedance data, because these models (so-called lumped models) improperly represent the distributed resistors associated with long and narrow spaces such as lateral intercellular spaces (LIS). A new distributed model of an epithelium is developed to take account of these structures and thereby obtain much better fits to the data. The extracted parameters include the resistance and capacitance of the apical and basolateral cell membranes, the series resistance and the ratio of the cross-sectional area to the length of the LIS. The capacitance values yield estimates of real area of the apical and basolateral membranes. Thus, impedance analysis can yield morphological information (configuration of the LIS, and real membrane areas) about a living tissue independently of EM. The effects of transport-modifying agents such as amiloride and nystatin can be related to their effects on particular circuit elements by extracting parameter values from impedance runs before and during application of the agent. Calculated parameter values were validated by independent electrophysiological and morphological measurements.