MOBILIZATION OF LEAD BY CALCIUM VERSENATE AND DIMERCAPTOSUCCINATE IN THE RAT

1. Calcium disodium ethylenediaminetetraacetate (CaNa2 EDTA) and meso- 2,3-dimercaptosuccinic acid (DMSA) individually and in permutation-com bination in various doses (0.1, 0.2 and 0.4 mmol/kg bodyweight) were i nvestigated for their efficacy to mobilize lead from vital tissues int o urine and faeces and to restore the lead-sensitive biochemical param eters in lead pre-exposed rats with a view to develop the most accepta ble treatment regimen for lead poisoning with a minimal loss of endoge nous essential elements. 2. The combined therapy was more effective th an a single chelator treatment. 3. The combination of 0.2 mmol/kg CaNa (2)EDTA + 0.4 mmol/kg DMSA caused a lower depletion of zinc, calcium a nd iron but possessed almost equal capability to that of 0,4 mmol/kg C aNa(2)EDTA + 0.4 mmol/kg DMSA to produce urinary as well as faecal exc retion of lead, to reduce the tissue burden of lead, including that of the brain, and to reverse lead-induced biochemical alterations. 4. Th e combination of 0.2 mmol/kg CaNa(2)EDTA + 0,4 mmol/kg DMSA has shown a definite improvement over previously reported combinations in terms of removal of lead from tissues, particularly the brain, restoration o f urinary delta-aminolevulinic acid levels and a decrease in the loss of body zinc and is, therefore, recommended for the treatment of lead intoxication.