In vitro toxicity induced by methylmercury on sympathetic neurons is reverted by L-cysteine or glutathione

Methylmercury (MeHg) is related to several deleterious effects on the vertebrate nervous system and part. of these effects are through interaction with sulfhydryl (-SH) group found in cellular proteins. We decided to characterize the dose-dependent effect of MeHg on the neurotoxicity and the neurite outgrowth induced effects on chick sympathetic neurons dissociated and purified in culture. In this model, MeHg inhibited neurite outgrowth (1-10 mu M) and induced cell death (1-10 mu M) after 48 h in culture. Since metal toxicity often generates reactive oxygen species, we tested if antioxidant compounds such as glutathione (GSH) or L-Cysteine (L-CYS) could block the deleterious effects promoted by MeHg. L-Methionine, another sulfur-containing amino acid, but without a SH group, was also used in this work. We show that GSH (10-100 mu M) and L-CYS (100 mu M), but not L-methionine (100 mu M), fully blocked neurite degeneration and sympathetic neuron cell death in culture. (C) 2007 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.