Huang Y, Wang X B, Gascoyne P R, Becker F F
Department of Molecular Pathology, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030,
Biochim Biophys Acta. 1999 Feb 4;1417(1):51-62. doi: 10.1016/s0005-2736(98)00253-3.
Human peripheral blood T-lymphocytes, normally resting at the G0 phase, were stimulated with phytohemagglutinin (PHA) and interleukin-2 (IL-2) to induce the cell division cycle. The cells were examined at 24-h intervals for up to 96 h by flow cytometry to determine cell cycle distributions and by electrorotation to determine dielectric properties. The average membrane specific capacitance was found to vary from 12 (+/-1.5) mF/m2 prior to stimulation to 10 (+/-1.5) and 16 (+/-3.5) mF/m2 at 24 and 48 h after stimulation, respectively, and to remain unchanged up to 96 h after stimulation. Scanning electron microscopy studies of the cells revealed an increased complexity in cell membrane morphology following stimulation, suggesting that the observed change in the membrane capacitance was dominated by the alteration of cell surface structures. The average electrical conductivity of the cell interior decreased from approximately 1.1 S/m prior to stimulation to approximately 0.8 S/m at 24 h after stimulation and showed little change thereafter. The average dielectric permittivity of the cell interior remained almost unchanged throughout the course of the cell stimulation. The percentage of T-lymphocytes in the S and G2/M phases increased from approximately 4% prior to stimulation to approximately 11 and approximately 34% at 24 and 48 h after stimulation, respectively. The large change in membrane specific capacitance between the 24 and 48 h time period coincided with the large alteration in the cell cycle distribution where the S and G2/M populations increased by approximately 23%. These data, together with an analysis of the variation of the membrane capacitance during the cell cycle based on the cell cycle-dependent membrane lipid accumulation, show that there is a correlation between membrane capacitance and cell cycle phases that reflects alterations in the cell plasma membrane.
人外周血T淋巴细胞通常处于G0期静止状态，用植物血凝素（PHA）和白细胞介素-2（IL-2）刺激以诱导细胞分裂周期。通过流式细胞术每隔24小时检查细胞，持续96小时，以确定细胞周期分布，并通过电旋转确定介电特性。发现平均膜比电容在刺激前为12（±1.5）mF/m2，在刺激后24小时和48小时分别变为10（±1.5）和16（±3.5）mF/m2，并且在刺激后96小时内保持不变。对细胞的扫描电子显微镜研究显示，刺激后细胞膜形态的复杂性增加，这表明观察到的膜电容变化主要由细胞表面结构的改变所致。细胞内部的平均电导率从刺激前的约1.1 S/m降至刺激后24小时的约0.8 S/m，此后变化不大。细胞内部的平均介电常数在细胞刺激过程中几乎保持不变。处于S期和G2/M期的T淋巴细胞百分比分别从刺激前的约4%增加到刺激后24小时的约11%和48小时的约34%。在24小时至48小时期间膜比电容的大幅变化与细胞周期分布的大幅改变相一致，此时S期和G2/M期群体增加了约23%。这些数据，连同基于细胞周期依赖性膜脂质积累对细胞周期中膜电容变化的分析，表明膜电容与细胞周期阶段之间存在相关性，这反映了细胞质膜的改变。
