DIFFERENT SENSITIVITIES TO EXTERNAL ATP IN PASSIVE PERMEABILITY OF TRANSFORMED MOUSE CELL LINES

Abstract
External ATP causes a passive permeability change in several transformed cells but not in untransformed mouse fibroblasts. The ATP-specific permeability change was observed also in B16 melanoma and L929 [neoplastic liver fibroblast] cells. The sensitivity to external ATP of these cells increased further when the concentration of intracellular ATP was lowered by addition of a mitochondrial inhibitor. In contrast, mouse 3T3 cells transformed by murine sarcoma virus did not respond to external ATP even when the intracellular ATP was depleted. Such differences in the ATP-sensitivity were not ascribed to the different concentrations of intracellular ATP.