Binggeli R, Weinstein R C, Stevenson D
Department of Anatomy and Cell Biology, University of Southern California School of Medicine, Los Angeles, USA.
Cancer Biochem Biophys. 1994 Oct;14(3):201-10.
Calcium ion affects ion permeability and membrane potential among many other aspects of cell function. Initial effects of increasing extracellular calcium upon membrane potential were studied in a quail fibrosarcoma (QT35) where calcium had a dose dependent effect, and normal quail fibroblasts, where there was little effect. Comparisons were then made in six different human hepatocellular carcinomas (Tong, HepG2, Hep3B, PLC/PRF/5, Mahlavu, and HA22T) in response to smaller changes in concentration. There were insignificant changes in membrane potential in two cell lines and significant elevations in four. Cytolysis by natural killer cells also declined in rough proportion to the increase in membrane potential. The less differentiated hepatocellular carcinoma cells have both higher baseline membrane potentials and a greater potential increase to increased calcium. By contrast, more highly differentiated tumor cells had paradoxically smaller membrane potentials and along with normal cells had small potential responses to calcium increases.
钙离子在细胞功能的许多其他方面影响离子通透性和膜电位。在鹌鹑纤维肉瘤（QT35）中研究了增加细胞外钙对膜电位的初始影响，在该细胞系中钙具有剂量依赖性效应，而在正常鹌鹑成纤维细胞中影响很小。然后对六种不同的人类肝癌细胞系（Tong、HepG2、Hep3B、PLC/PRF/5、Mahlavu和HA22T）进行比较，以研究较小浓度变化时的反应。在两个细胞系中膜电位变化不显著，在四个细胞系中膜电位显著升高。自然杀伤细胞的细胞溶解作用也大致与膜电位的升高成比例下降。分化程度较低的肝癌细胞具有较高的基线膜电位，并且对钙增加的电位升高幅度更大。相比之下，分化程度较高的肿瘤细胞膜电位反而较小，并且与正常细胞一样，对钙增加的电位反应较小。
