Protective effect of an inhibitor of nitric oxide synthase on sulphur mustard toxicity in vitro

Although sulphur mustard is one of the oldest chemical warfare agents, its mechanism of toxic action is still not understood and as a consequence, no antidotes exist that are effective against this agent. Pretreatment of chick embryo neuron cultures with the well-known nitric oxide synthase (NOS) inhibitor L-nitroarginine methyl ester (L-NAME) was found to confer significant protection against sulphur mustard-induced cell death. However, these protective effects were not mediated through the inhibition of NOS. These findings may provide clues to the eventual understanding to sulphur mustard toxicity, and also suggest that L-NAME has significant novel pharmacological effects other than the inhibition of NOS.