Antibody to lactate dehydrogenase III. Uptake, accumulation and specific intracellular action in malignant cells

Abstract

1. 1. Indirect fluorescent-antibody studies showed that homologous anti-lactate dehydrogenase was taken up and accumulated, in an antigenicallya active form, within rabbit Vx-2 carcinoma cells, mouse Ehrlich carcinoma cells and BW5147 leukemic cells growing in vitro . The times of entry of these antibodies correlated with the times of onset of metabolic inhibitions. Normal cells tested (rabbit leucocytes, kidney and muscle cells and mouse kidney and muscle cells) did not accumulate these antibodies. 2. 2. Guinea pig serum (containing complement) promoted the rapid entry of anti-enzymes into Ehrlich cells and permitted the use of Warburg respirometer studies on respiration and glycolysis by cell suspensions. Anti-lactate dehydrogenase inhibited aerobic glycolysis but did not affect respiration; anti-mitochondria inhibited respiration without affecting aerobic glycolysis; anti-serum protein did not affect aerobic glycolysis but stimulated respiration. 3. 3. Ehrlich cells growing in vitro , in the absence of complement, similarly showed differential inhibitions by the different antibodies but only subsequent to 24 h. Anti-lactate dehydrogenase and anti-serum protein inhibited glycolysis but stimulated respiration; anti-mitochondria inhibited respiration but stimulated glycolysis. 4. 4. The medium bathing cell cultures treated with anti-lactate dehydrogenase accumulated two abnormal products tentatively identified as pyruvic acid and glycerol. Cultures treated with anti-mitochondria accumulated three abnormal products, two of which were probably pyruvic acid and α-glycerophosphate.