Inorganic ion concentrations in Ehrlich ascites carcinoma cells and fluid.

The concentrations of sodium, potassium, magnesium, cal cium, chloride, and phosphate were determined in Ehrlich ascites tumor cells and fluid after 5, 7, 9, and 12 days of growth. Material obtained after the 12th day showed peculiar intra cellular ion patterns, presumably related to the near-terminal condition. Material drawn after 5-9 days of growth represented viable cells. The intracellular ion values of these cells were com pared to published values for erythrocytes and muscle cells, and to their own developmental stage. The tumor cells more closely resembled erythrocytes with respect to the concentra tions of sodium, potassium, and chloride, but had in common with muscle much inorganic phosphate. The 5-day-old cells, which represented a population in the latter phases of rapid multiplication, had less intracellular potassium and phosphate, but more sodium than 7or 9-day-old cells. It is suggested that these findings reflect the greater energy requirements of the dividing cells. The extracellular ion concentrations were similar to that ex pected for blood plasma, with the following exceptions: a gen erally low but variable sodium level after 5 days of growth; a very high potassium level; and a high level of chloride after 12 days of growth. The possible reasons for these deviations are discussed.