The metabolism of labeled lactate and pyruvate by three strains of Ehrlich ascites tumor cells, H, HL, and W, was studied. The major products from the acids were CO2, amino acids (mainly alanine), and acetate. HL-cells are characterized by a high 14C yield in amino acids, and W-cells are characterized by their large acetate production. The rate of lactate and pyruvate oxidation was equal in H- and HL-cells, but W-cells oxidized pyruvate faster than lactate. Phenazine methosulfate stimulated lactate oxidation in W-cells but not in the other two strains. Aminooxyacetate (2 mm) depressed 14C yields in amino acids by 80 to 90%. It had no effect on lactate oxidation in H- and HL-cells, but depressed it in the W-cells by about 40%. The results suggest that the oxidation of cytosolic reduced nicotinamide adenine dinucleotide is rate limiting in the oxidation of lactate by W-cells but not the H- and HL-cells.
Supported by USPHS Grants 5R01AN 1260405 and RR 05468.