EFFECT OF CHELATION ON THE FATE OF INTRAVENOUSLY ADMINISTERED CADMIUM IN RATS

Rats were injected i.v. with 15 nmol of 109Cd-labelled CdCl2 or cadmium chelates, and cadmium accumulation in blood, kidney, liver and gastrointestinal tract was measured for up to 30 min after injection. Cd given as CdCl2 accumulated predominantly in the liver (60 to 70 per cent of the dose) with less in the gastrointestinal tract (GIT) and kidney (2 per cent and 12 per cent respectively). Cd cysteine (d and l), Cd histidine, Cd penicillamine and Cd glutathione, gave patterns similar to that of CdCl2, but Cd EDTA and Cd BAL differed. After Cd EDTA, liver, kidney and skeletal muscle 109Cd concentrations were similar at about 20 per cent of the dose, but GIT concentrations were low. Cd EDTA persisted longer than any of the other complexes in the blood. Cd BAL accumulated predominantly in the liver (90 per cent); there was virtually no accumulation in the kidney (0·5 per cent). These studies suggest that the Cd cys, Cd GSH, Cd His and Cd penicillamine complexes were unstable in vivo, and dissociated to release the free cation. The results also indicate that BAL and EDTA altered the distribution pattern in very different manners and may thus alter Cd toxicity. © 1979.