[The cytostatic action of the K+/H+ antiporter nigericin]

A decrease in pH in Ehrlich ascites carcinoma cells to 6.3 leads to intracellular DNA synthesis inhibition. The inhibitory effect was achieved in the course of incubation of cells at pH 6.2 as well as by the addition of low-dose K+/H+ antiporter antibiotic nigericin. DNA synthesis inhibition by nigericin was not associated with significant decrease in ATP level or mitochondrial membrane potential. The effect was mediated by a decrease in intracellular pH rather than by a decrease in intracellular potassium level or elevation in that of intracellular sodium which accompanied nigericin treatment.