MONOISOAMYL MESO-2,3-DIMERCAPTOSUCCINATE AS A DELAYED TREATMENT FOR MERCURY REMOVAL IN RATS

Monoisoamyl meso-2,3-dimercaptosuccinate (Mi-ADMS) was found to be sup erior to meso-2,3-dimercaptosuccinic acid (DMSA) in decreasing the bod y burden of Hg-203 in rats under conditions of early treatment. in thi s experiment Mi-ADMS was used as late treatment for mercury removal. A lbino rats aged 6 weeks and 7-day-old sucklings received a single intr aperitoneal injection of Hg-203 (as nitrate). Two weeks later they wer e treated with DMSA or Mi-ADMS (0.25 mmole/kg bw) on two consecutive d ays. The radioactivity in the carcass (whole body after removal of the gastrointestinal tract), liver, kidneys and brain was determined by s olid crystal gamma scintillation counting six days after chelation the rapy administration (3 weeks after Hg-203 application). Both chelators reduced the body burden of mercury compared to controls. The effect o f Mi-ADMS was superior to DMSA treatment in older rats for decreasing carcass and kidney retention, and in suckling rats for decreasing carc ass, liver, and kidney retention. They were equally effective in decre asing brain retention in older rats and had no effect on brain retenti on in sucklings. The efficiency of Mi-ADMS in reducing the body burden of mercury was generally higher than the efficiency of the DMSA treat ment. Therefore, Mi-ADMS deserves further attention as a late treatmen t for mercury removal.