Substrate utilization by Ehrlich mouse ascites carcinoma cells.

Abstract

With the use of the Ehrlich mouse ascites carcinoma cell (a variant of the Ehrlich breast carcinoma), a washed tumor cell system was obtained which could be employed for chemical and biological studies. 1. The oxidative metabolism of this system was not appreciably influenced by wide changes in total ionic strength or by variations in ionic pattern. The metabolism was, however, adversely affected by a lowering of the pH below 7.4, and irreversible enzyme damage was apparent above pH 7.4. 2. The quantity of cells in the system could be determined by direct count, by packed cell volume measurement, or by dry weight determination, the latter two being better criteria for quantitation. 3. The washed tumor cell system had a lowered concentration of exogenous substrates and, after 1 hour of respiration, showed a lowered oxygen consumption. The “endogenous” respiration could be markedly stimulated by adding glutamate, lactate, pyruvate, oxalacetate, malate, succinate, α-ketoglutarate, citrate, aspartate, or alanine. 4. The addition of small amounts of glucose to the cell system stimulated, whereas large quantities inhibited, oxidation. Glucose was utilized at a rate of about 0.96 mg/hour/0.04 ml (17 × 105) tumor cells. 5. Lactate was utilized at a rate of about 0.13–0.27 mg/hour/0.04 ml cells. The higher rate was found when glucose was the substrate—this in spite of the diminished oxidative metabolism.