Glutamate is an excitatory transmitter released from neurons. It communicates information rapidly by

Glutathione (GSH; L- -glutamyl-L-cysteinl-glycine) plays an important role in the prevention of radical mediated injury to the body. It does so as a radical scavenger and by supplying GSH to the antioxidant enzymes described in Chapter 29 . In conjunction with superoxide dismutase (SOD), which converts superoxide anions into hydrogen peroxide (H2 02 ), glutathione peroxidase (GSHPx) converts H2 02 , into water (1 ). As a result of the second conversion, GSH is oxidized to glutathione disulfide (GSSG). In this way, GSH acts as a cofactor in the removal of toxic radicals from the body. During oxidative stress, GSH levels decline and GSSG increases, which can influence signal transduction by stimulating NF-kB activation (2 ). GSH is also thought to be a donor of glutamyl groups in amino-acid transport (3 ).