Effect of hyperbaric oxygen on the cytotoxicity of adriamycin and nitrogen mustard in cultured Burkitt's lymphoma cells.

The effects of hyperbaric oxygen (HPO) exposure on the cytotoxicity of Adriamycin (ADM) and nitrogen mustard have been examined in Burkitt's lymphoma cells (P3J) in vitro. Exposure of cells to 3 atmospheres of pressure HPO for 2 hr produces inhibition of DNA synthesis and mitosis. Simultaneous exposure to HPO and ADM results in decreased cytotoxicity compared to drug treatment alone. However, exposure to ADM (0.15 microgram/ml) 2 to 8 hr before or after HPO produces an increase in drug effect. There is no potentiation of lower ADM concentrations. Cytotoxicity is increased when cells are exposed to HPO during, before, or after exposure to nitrogen mustard (NSC 762) (0.15 and 0.25 microgram/ml). Lower nitrogen mustard (NSC 762) concentrations are not potentiated. HPO potentiation of antineoplastic agents appears to depend upon the agent studied, the concentration of the agent, and the scheduling of the drug and HPO exposure.