Identification and characterization of uptake systems for cystine and cysteine in cultured astrocytes and neurons: Evidence for methylmercury-targeted disruption of astrocyte transport

Maintenance of appropriate intracellular glutathione (GSH) levels is crucia l for cellular defense against oxidative damage. A suggested mechanism of m ethylmercury (MeHg) neurotoxicity implicates the involvement of oxygen radi cal formation and a decrease in cellular levels of GSH. Astrocytes play an important role in providing GSH precursors to neurons, and as will be discu ssed in this review, altered GSH homeostasis likely leads to impairment of astrocytic handling of glutamate, and neuronal energy metabolism. The revie w summarizes recent observations on transport systems for cysteine and cyst ine, precursors of GSH, in primary cultures of astrocytes and neurons, and their sensitivity to MeHg treatment. (C) 2001 Wiley-Liss, Inc.