Effects of combined treatment with diethyldithiocarbamate and diethylenetriaminepentaacetate on organ distribution and excretion of cadmium

Diethyldithiocarbamate (DDTC) and diethylenetriaminepentaacetate (DTPA) were assessed to determine if combination treatment with these two chelators of different chemical classes would enhance mobilization and excretion of metallothionein-bound cadmium (Cd) from selected organs of mice which had earlier received 0.03 mg of CdCl2 . 2.5 H2O along with 1.0 microCi of 109Cd. In addition to measuring individual organ radioactivity after seven and after 13 injections of each compound individually as well as in combination, whole body Cd burden was measured, and the routes and rates of Cd excretion were determined. When used alone, DDTC was effective in mobilizing Cd from kidney, liver, intestine, and spleen. The DTPA when used alone was not consistently effective in reducing Cd burdens in any of the organs assessed. Coadministration of DDTC and DTPA promoted an enhancement of Cd mobilization from liver, kidney, spleen, and intestine over that which was observed with DDTC alone. When DTPA was administered with DDTC, it did not prevent accumulation of Cd in lung and brain which was observed upon treatment with DDTC alone. Combined treatment did produce a more marked depletion of total body 109Cd burden than did the administration of DDTC alone. A more rapid rate of both fecal and urinary excretion of Cd was observed when the chelators were coadministered. It was concluded that at least an additive or possibly supraadditive effect may be obtained by combining a dithiocarbamate chelator with one of the aminocarboxylate class in total body Cd decorporation.