Mobilisation of cadmium by meso- and racemic-2,3-dimercaptosuccinic acid (DMSA) in rats

A higher efficiency of cadmium binding with racemic than with meso-2,3-dime rcaptosuccinic acid (rac-DMSA; meso-DMSA) was found in an in vitro speciati on model by Fang et al. (1996). This finding has not yet been tested in viv o. This paper presents results on mobilisation of cadmium by meso- and rac- DMSA in rats. Cadmium chloride was administered as the radioactive isotope Cd-109 intraperitoneally to all animals. One group was an untreated control and two groups were treated with meso- and rac-DMSA, respectively. Treatme nt with chelators was applied twice, immediately after Cd-109 and 24 hr aft erwards intraperitoneally at the dose of 1 mmol/kg, each. Six days later ra dioactivity was measured in the liver and kidneys. Whole-body counting was carried out on days 1, 2, 3 and 6 of the experiment. At the end of the expe riment, both treatments caused a decrease in Cd-109 whole-body retention wi th lac-DMSA being more efficient (decrease from 83% in control to 74% and 6 4% in groups treated with meso- and Inc-DMSA, respectively). The same reduc tion of Cd-109 was obtained by both chelators in the liver (from 57% to abo ut 47%). In the kidney only lac-DMSA produced significant reduction of Cd-1 09 (from 5.3% to 3.5%). In conclusion, these results show modest reduction of cadmium in the body by two isoforms of DMSA with rac-DMSA being slightly more efficient than meso-DMSA.