Huang Y, Wang X B, Hölzel R, Becker F F, Gascoyne P R
Department of Molecular Pathology, University of Texas M D Anderson Cancer Center, Houston 77030, USA.
Phys Med Biol. 1995 Nov;40(11):1789-806. doi: 10.1088/0031-9155/40/11/002.
Electrorotation (ROT) spectra of Friend murine erythroleukaemia DS19 cells were measured in the frequency range 10 kHz-100 MHz as a function of suspension osmolality and cell differentiation treatment with hexamethylene bisacetamide (HMBA). A minimization program was employed to curve-fit the measured spectra using a single-shell dielectric model, allowing the derivation of cellular interior conductivity and permittivity (valid for the frequency range 10-100 MHz) and the cytoplasmic membrane capacitance (its dependence on the cell differentiation state and suspension osmolality having been reported earlier). Following HMBA treatment, DS19 cells exhibited a slight increment in average interior permittivity and a decrement in interior conductivity, although the changes were not statistically significant. For both untreated and HMBA treated samples, the average interior conductivity increased and permittivity decreased with increasing suspension osmolality. Of significance was that the average permittivity of cell interiors was larger than that of pure water. The electrorotation spectra of freshly prepared cell nuclei were measured, and the derived nuclear dielectric parameters were employed in numerical simulations to investigate the effects of nuclei on the ROT spectra of intact cells. Other cellular internal structures such as mitochondria were also analysed using theoretical simulations. It was concluded that the derived large permittivity values did not result from cell nuclei or mitochondria, and, instead, we suggest that they may arise from the combined effects of several cytoplasmic organelles.
在10 kHz至100 MHz频率范围内，测量了弗氏小鼠红白血病DS19细胞的旋转电泳（ROT）光谱，该光谱是悬浮渗透压和用六亚甲基双乙酰胺（HMBA）进行细胞分化处理的函数。采用最小化程序，使用单壳介电模型对测量光谱进行曲线拟合，从而得出细胞内部电导率和介电常数（在10 - 100 MHz频率范围内有效）以及细胞质膜电容（其对细胞分化状态和悬浮渗透压的依赖性已在之前报道）。经HMBA处理后，DS19细胞的平均内部介电常数略有增加，内部电导率略有下降，尽管这些变化在统计学上并不显著。对于未处理和经HMBA处理的样品，随着悬浮渗透压的增加，平均内部电导率增加，介电常数降低。值得注意的是，细胞内部的平均介电常数大于纯水的介电常数。测量了新制备的细胞核的旋转电泳光谱，并将导出的核介电参数用于数值模拟，以研究细胞核对完整细胞ROT光谱的影响。还使用理论模拟分析了其他细胞内部结构，如线粒体。得出的结论是，导出的大介电常数并非由细胞核或线粒体导致，相反，我们认为它们可能是由几种细胞质细胞器的综合作用引起的。
