Wanshan mercury mine is the largest mercury deposit in Guizhou Provinc e of China, but there were few reports on mercury toxic effect in the mining are a. In order to study the neurotoxicity of food from Wanshan mercury mine area an d probe into the effect of food from Wanshan mercury miner area on the changes o f brain oxidative damage and expression of c-fos gene. The rats were exposed to mercury contaminated food for 20 d. The content of malondialdehyde (MDA), supero xide dismutase (SOD), GSH-peroxidase (GSH-px) and Glutathione (GSH) in rat brain was measured, and the effect of mercury contaminated rice on the expression of c-fos mRNA in rat brain and the expression of c-FOS protein in cortex, hippocamp us were observed using reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemical methods. The results showed the levels of GSH, MDA, SOD a nd of GSH-dependent enzymes in the rat brain changed between exposure groups and control group; The mercury polluted rice induced significantly the expression o f c-fos mRNA; the c-FOS positive cells in hippocampus and cortex of exposure gro ups were significant different from control group (P<0.01). It could be conclude d that oxidative stress signals could contribute to the induction of immediate e arly genes (IEGs); free radicals and their by-products might not only cause oxid ative damage, but also influenced gene expression; IEGs c-fos participated in th e toxicity process of brain injury by mercury polluted food.
