[Effect of ammonia on the Crabtree effect of 2 strains of Ehrlich ascites tumor]

Some features of energy metabolism in two strains of Ehrlich ascites tumor cells are presented in this paper. A correlation between malignancy and activity of aerobic glycolysis was observed. In the Roma strain, ammonium ions (1-10 mM) enhance the aerobic glycolysis and the Crabtree effect induced by 5 mM glucose. In spite of the activation of glycolysis, the total amount of pyruvate and lactate decreased in the presence of ammonium, because a drain of pyruvate takes place through the pyruvate dehydrogenase complex. Ammonium ions fail to modify the Crabtree effect or the aerobic glycolysis in CBM strain. In these cells, NH4+ did not affect the pyruvate and lactate produced from glucose. It is suggested that ammonium effect on the aerobic glycolysis in Roma strain could be adventageous for tumor growth, because there is an increase in the availability of carbon skeleton from glucose to account for the assimilation of NH4+ and consequently for the synthesis of aminoacids.