Evaluation of micromotion of vascular endothelial cells with estrogen in electrical cell-substrate impedance sensing (ECIS) method using a mathematical model cell-to-cell distance and cell-to-substrate distance

We proposed a mathematical model for the micro-dynamics of cultured cells measured with ECIS (Electrical Cell-substrate Impedance Sensing system. Our mathematical model is composed of culture medium impedance between cells (Z/sub sol/), cell impedance (Z/sub c/), and polarization impedance of the electrode (Z/sub p/). It was found that whether cell-to-cell or cell-to-substrate gaps caused the changes in the impedance could be determined based on the changes in the total resistance and reactance (capacitance). Cell-to-cell gaps mainly affects the total resistance value. Cell-to-substrate gaps mainly affects total capacitance value. Based on these results, when the cultured endothelial cells (HUVEC) were stimulated with estrogen for 40 hours, it was proved that the cell-to-cell distances decreased, even though the cell-to-substrate distances slightly increased. This result suggests that the barrier function of endothelium is fortified by estrogen.