Effect of long-term sodium selenite supplementation on levels and distribution of mercury in blood, brain and kidneys of methyl mercury-exposed female mice.

Female Balb/c CA mice were supplemented for seven weeks with 0, 0.6 and 3 p.p.m. Se in tap water and were then exposed to a single oral dose of Me203Hg (2 mumol/kg). Se supplementation continued for 56 days after MeHg dosage. Supplemented animals showed enhanced activity of glutathione peroxidase in the blood. Twenty-four hr after MeHg dosage, the level and distribution of Hg in blood, blood cells, and kidneys were not influenced by Se exposure. However, in the brain the Hg accumulation was increased and Hg distribution was altered by Se supplementation. Fifty-six days after MeHg dosage, 70% to 80% of the dose had been eliminated from the body, and the brain of the 3 p.p.m. group still had a higher Hg level than the control group. Otherwise, there was no consistent effect of Se supplementation on retention of Hg in the animals. It is indicated that Se influences tissue accumulation and intracellular distribution of Hg through tissue-specific mechanisms rather than through a more general effect on Hg sequestration and transport in the blood.