Distribution of methylmercury and inorganic mercury in neonate hamsters dosed with methylmercury during fetal life

The study of the effects of methylmercury (MeHg) contamination has intensif ied since the MeHg outbreaks in Japan and Iraq. However, most of these stud ies used high doses of MeHg to obtain its most severe effects. This work id entified the MeHg targets in neonate hamsters after administration of two d ifferent single oral doses of radiolabeled methylmercury chloride ((MeHgCl) -Hg-203) to two groups of pregnant hamsters. The low-dose group received 0. 05 mug of Hg-203 as (MeHgCl)-Hg-203 p,, gram of body weight and the radioac tivity was 6.6 x 10(3) Bq. The high-dose group received 0.55 mug of Hg-203 as (MeHgCl)-Hg-203 per gram of body weight with 2 x 10(4) Bq. In the first day of life, the brain was the organ with the highest (MeHg)-Hg-203 concent ration, followed by the liver, kidneys, and intestines. However, these valu es of (MeHg)-Hg-203 decreased at different rates in all organs until 12 day s of life, whereas total Hg-203 in the body did not change during the same period. This suggests an age-dependent (MeHg)-Hg-203 body distribution inst ead of an elimination of (MeHg)-Hg-203 from the body. (C) 2001 Acaaemic Pre ss.