DISTRIBUTION OF MERCURY IN RABBITS SUBCHRONICALLY EXPOSED TO LOW-LEVELS OF RADIOLABELED METHYL MERCURY

The metabolism of methyl mercury (MeHg) has been studied in rabbits administered Hg-203-labeled methyl mercuric chloride, 0.125-mu-mol/kg body weight, twice a week for 9 weeks, by intravenous injection. Twelve weeks after cessation of treatment, about 54% of the administered dose had been excreted in faeces and 5% in urine. After one week, the highest concentration of Hg-203 was found in fur (8.6 nmol Hg/g). Substantially lower concentrations were found in kidney (2.5 nmol/g), liver (0.9 nmol/g), brain (0.4 nmol/g), muscle (0.3 nmol/g) and blood (0.1 nmol/g). The rate of elimination of Hg-203 from brain, muscle and blood was faster (t1/2 about 12 days) than that from kidney and liver (t1/2 about 28 days). The relative amount of inorganic Hg in kidney and liver increased with time after cessation of treatment. The highest fractions were 85 and 70%, respectively. In brain, no significant demethylation of MeHg could be detected.