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4119679 
Journal Article 
Effects Of Chelating Agents On Oral Uptake And Renal Deposition And Excretion Of Cadmium 
Engstrom, B 
1984 
Yes 
Environmental Health Perspectives
ISSN: 0091-6765
EISSN: 1552-9924 
NIOSH/00144407 
54 
219-232 
Gastrointestinal absorption, transport, tissue deposition, and excretion of cadmium (7440439) were investigated in mice after single or repeated exposure with or without chelating agents. Male CBA-mice received a single oral 60 milligrams/kilogram (mg/kg) dose of cadmium-109 in combination with a single 600mg/kg dose of nitrilotriacetic-acid (139139) (NTA), sodium-tripolyphosphate (7758294) (STP), or 60 or 600mg/kg ethylenediaminetetraacetic-acid (60004) (EDTA). Animals were observed, and blood cadmium concentrations followed, from 5 minutes to 21 days before dissection and tissue analysis. Female CBA-mice received a single oral 15 micrograms/kg dose of radioactive cadmium in combination with cadmium and 50 or 500 parts per million (ppm) of these chelating agents in their drinking water and were observed for 18 months. Acute cadmium toxicity was reduced in mice given cadmium in combination with EDTA. At all times from 5 minutes to 5 hours after dosing blood cadmium concentrations were lowest in mice exposed to cadmium plus STP. Almost all cadmium in kidneys of mice exposed to cadmium and EDTA at the higher doses was bound in the cadmium complex, while at the lower dose of EDTA part of the cadmium was bound to high molecular weight proteins. Cadmium 24 hour elimination was increased from 20 percent with cadmium alone to 45 percent with the higher and 35 percent with the lower dose of EDTA. Whole body retention at 21 days was 4.4 percent with cadmium alone, 2 percent with NTA and 5.5 percent with STP. With repeated exposure no substantial differences in whole body or organ retention of cadmium were seen after treatment with different chelating agents. Chelating agents did not affect mortality over 18 months. The author concludes that the effects of different chelating agents on acute cadmium toxicity and metabolism are produced by change in the stability of the chelate complexes and the availability of metal binding ligands in-vivo.