Sagi-Eisenberg R, Pecht I
J Membr Biol. 1983;75(2):97-104. doi: 10.1007/BF01995629.
The membrane potential of rat basophilic leukemia cells (RBL-2H3 cell line) has been determined by monitoring the distribution of the lipophilic [3H] tetraphenylphosphonium cation between the cells and the extracellular medium. By this method, the determined potential of these cells, passively sensitized with IgE, is -93 +/- 5 mV (mean +/- SEM, interior negative). Almost 40% of this membrane potential is rapidly collapsed upon the addition of the proton carrier, carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (FCCP). It is suggested that the FCCP-sensitive fraction of the total membrane potential results from the accumulation of this cation by the mitochondria, which maintains a negative membrane potential. Thus, the resting plasma membrane potential of these cells equals -55 +/- 6 mV. During the process of immunological stimulation by antibodies directed against cell membrane bound IgE, the membrane potential decreases. Moreover, there is a correlation between the extent of degranulation of the cells and the depolarization. It is concluded that in common with other secretory systems, depolarization of the plasma membrane is involved in the stimulus-secretion coupling of the histamine secreting RBL cells.
通过监测亲脂性的[³H]四苯基鏻阳离子在大鼠嗜碱性白血病细胞(RBL - 2H3细胞系)与细胞外培养基之间的分布情况,测定了其膜电位。用这种方法,测定的经IgE被动致敏的这些细胞的电位为 - 93±5 mV(平均值±标准误,细胞内为负)。加入质子载体羰基氰对三氟甲氧基苯腙(FCCP)后,几乎40%的这种膜电位会迅速消失。这表明总膜电位中对FCCP敏感的部分是由线粒体积累该阳离子导致的,线粒体维持着负膜电位。因此,这些细胞静息质膜电位等于 - 55±6 mV。在用针对细胞膜结合IgE的抗体进行免疫刺激过程中,膜电位会降低。此外,细胞脱颗粒程度与去极化之间存在相关性。得出的结论是,与其他分泌系统一样,质膜去极化参与了组胺分泌性RBL细胞的刺激 - 分泌偶联过程。