Lo C M, Keese C R, Giaever I
Department of Physiology, University of Massachusetts Medical School, Worcester, Massachusetts, 01605, USA.
Exp Cell Res. 1999 Aug 1;250(2):576-80. doi: 10.1006/excr.1999.4538.
Transepithelial resistance (TER) measurement has often been used to study the paracellular transport properties of epithelia grown on permeable filters, especially the barrier function of tight junctions. However, the TER value includes another source, the resistance caused by cell-substrate contact, that may give rise to a high TER value if cell-substrate separation is small. In this study we use electric cell-substrate impedance sensing (ECIS) to measure both paracellular resistance and the average cell-substrate distance of MDCK (II), HEp-2, and WI-38 VA13 cells. Comparing ECIS data with those from TER measurements of cell layers cultured on polycarbonate filters, we can obtain the approximate extra resistance resulting from cell-substrate contact for each cell type. The value of cell-substrate resistance was also estimated by two theoretical calculations that bracket the true values. Our results demonstrate that cell-substrate contact substantially influences the TER data measured using polycarbonate filters and that the extra resistance due to cell-substrate spaces depends on both cell type and filter property.
跨上皮电阻（TER）测量经常被用于研究生长在可渗透滤膜上的上皮细胞的细胞旁转运特性，尤其是紧密连接的屏障功能。然而，TER值包含另一个来源，即细胞与底物接触所产生的电阻，如果细胞与底物的分离较小，该电阻可能导致TER值较高。在本研究中，我们使用电场细胞-底物阻抗传感（ECIS）来测量MDCK（II）、HEp-2和WI-38 VA13细胞的细胞旁电阻以及平均细胞-底物距离。通过将ECIS数据与在聚碳酸酯滤膜上培养的细胞层的TER测量数据进行比较，我们可以获得每种细胞类型因细胞-底物接触而产生的近似额外电阻。细胞-底物电阻值还通过两种理论计算进行了估算，这两种计算结果框定了真实值。我们的结果表明，细胞-底物接触对使用聚碳酸酯滤膜测量的TER数据有显著影响，并且由于细胞-底物间隙产生的额外电阻取决于细胞类型和滤膜特性。
