SODIUM FLUORESCEIN ACCUMULATION IN CULTURED-CELLS

The mechanism of intracellular fluorescein accumulation was investigat ed by studying fluorescein accumulation kinetics in individual cells i n culture. The experiments were done with K562 human erythroleukemia c ell culture and a primary culture of human embryonic skin fibroblasts. Various experimental conditions were used by varying pH and ion compo sition of the external media, and/or temperature. All the experimental results obtained axe in support of the proposed theoretical model des cribing fluorescein accumulation in cells along the pH gradient. In ad dition, we could show that fluorescein molecules are bound to some int racellular macromolecules. Fluorescein accumulation in the cells studi ed does not depend on their malignant nature. It. is therefore reasona ble to conclude that fluorescein accumulation observed in clinical inv estigations of human gastric cancer is governed by the pH gradient bet ween the cells and the extracellular fluid; this gradient is much grea ter in the tumor than in normal tissues.