Action of misonidazole on L5178Y-R and L5178Y-S cells. I. Comparison with antimycin A and potassium cyanide under aerobic conditions.

Effects of treatment with misonidazole under aerobic conditions were examined in L5178Y-R and L5178Y-S cells. These cells slightly differ in susceptibility to the drug, however, the effects of treatment are similar: 1. slowing down growth without affecting viability at low doses; 2. cell lethality at higher doses with rapid elimination of dead cells from the population and resuming normal growth; 3. decrease in 3H-thymidine incorporation. These effects of misonidazole were strikingly similar to those of antimycin A (1 microgram/ml) and KCN (1 mM). It seems that the common cause of the described manifestations of cellular damage inflicted by all three chemicals is energy depletion due to disturbances in the function of mitochondrial electron transport.