METHYLMERCURY POISONING INDUCES OXIDATIVE STRESS IN THE MOUSE-BRAIN

CS7BL/6J mice were intoxicated by injection of 2.5 mg/kg body wt of me thylmercuric chloride (MMC) daily for 3, 7, and 14 days, and the relat ive concentrations of superoxide and hydrogen peroxide and the specifi c activity of superoxide dismutase (SOD) were determined in various ce llular fractions of the brain. High brain levels of Hg were associated with significantly increased amounts of superoxide and hydrogen perox ide by Days 3, 7, and 14 and with markedly reduced SOD activity by Day s 7 and 14. Such a rise in the levels of reactive oxygen species indic ates the induction of oxidative stress within brain tissue. This sugge sts that suppression of antioxidant activity, including that of SOD an d glutathione, together with disturbances in the mitochondrial electro n transport chain, may contribute to the induction of oxidative stress in the mouse brain following MMC poisoning. (C) 1994 Academic Press, Inc,