Protection against misonidazole-induced toxicity in vitro by non-steroidal anti-inflammatory agents.

Overnight exposure of Chinese hamster cells, V-79-753B, to certain non-steroidal anti-inflammatory agents (NSAIA) including indomethacin (5 x 10(-5)M), benoxaprofen (5 x 10(-5)M) or aspirin (10(-4)M) protected against misonidazole-induced toxicity both in air and in hypoxia at 37 degrees C. In no instance was the radiosensitivity of cells affected by these treatments nor was there any effect on the amount of acute hypoxic cell radiosensitization produced by 1.0 mM misonidazole. There was no protection against misonidazole-induced toxicity when cells were pretreated with theophylline (10(-3)M). Protection against misonidazole-induced toxicity by benoxaprofen was not reversed by the addition of 1 microgram/ml prostaglandin E1 or F1 alpha. The results are discussed in terms of possible mechanisms.