Effect of chelating agent structure on the mobilization of cadmium from intracellular deposits.

An examination of the efficacy of several structural types of chelating agents in the removal of cadmium from its intracellular deposits in mouse liver and kidneys reveals that of the structural types examined, only dithiocarbamates and a vicinal dithiol were able to mobilize cadmium from such intracellular sites. Esters of L-cysteine, a macrocyclic thioether, and a disulfide of a dithiocarbamate were unable to cause any appreciable decrease in either renal or hepatic cadmium levels. Charged groups such as carboxylic acid groups reduce the efficacy as well as the toxicity of the structural types that can otherwise mobilize such cadmium. It was also found that the administration of a cadmium-binding polymer ip leads to only a very slight net excretion of cadmium, while the po administration of this polymer leads to no net additional cadmium excretion. Of the compounds newly reported here, some are approximately equal in cadmium-mobilizing efficacy to the most effective of previously reported compounds.