Lead amplifies glutamate-induced oxidative stress.

Lead markedly amplified L-glutamate-induced oxidative stress, that is, increased L-glutamate-induced production of reactive oxygen species, decreased cellular glutathione, and induced cytotoxicity in human neuroblastoma cells. It was notable that oxidative burst induced by L-glutamate alone was observed only when neuronal glutathione was depleted. A role of protein kinase C (PKC) in glutamate-induced production of reactive oxygen species is likely because it was blocked by a PKC inhibitor. We suggest here that the mechanism whereby lead causes its neurotoxicity may be through the amplification of glutamate-induced oxidative stress, possibly through PKC activation.