Comparative effects of Ca-ethylenediaminetetraacetic acid (EDTA), ZnEDTA, and ZnCaEDTA in mobilizing lead.
Male Long-Evans rats weighing approximately 240 g were given (Pb) at 14 mg/kg as the acetate by slow iv infusion 17 days prior to chelate treatment. The chelating agents were administered by continuous iv infusion at either 1 mmol/kg over 6 hr or 6 mmol/kg over 24 hr or at 0.16 mmol/kg/day by sc injections. ZnEDTA was 60% and ZnCaEDTA 76% as effective as CaEDTA in promoting urinary Pb excretion at 1 mmol/kg over 6 hr, iv. At 6 mmol/kg/24 hr, iv, ZnEDTA was 76% and ZnCaEDTA 98% as effective as CaEDTA. Mean urinary Pb excretion for each chelate via the sc route and the lowest iv route of administration was the same. Blood delta-aminolaevulinic acid dehydratase (ALAD) activity (an indicator of Pb toxicity) was enhanced approximately twofold by CaEDTA, two and one-half-fold by ZnCaEDTA, and fivefold by ZnEDTA treatment. It is suggested that the safety of EDTA can be markedly enhanced if administered as a ZnCaEDTA chelate without appreciably diminishing its efficacy in promoting urinary Pb excretion.
D000818:Animals; D003300:Copper / Q000652:urine; D004353:Drug Evaluation, Preclinical; D004492:Edetic Acid / Q000627:therapeutic use*; D007263:Infusions, Parenteral; D007279:Injections, Subcutaneous; D007501:Iron / Q000652:urine; D007854:Lead / Q000652:urine; D007855:Lead Poisoning / Q000188:drug therapy*; D008297:Male; D008345:Manganese / Q000652:urine; D000623:Porphobilinogen Synthase / Q000097:blood / Q000378:metabolism; D051381:Rats; D013054:Spectrophotometry, Atomic
D007854:Lead; D008345:Manganese; D003300:Copper; D004492:Edetic Acid; D007501:Iron; D000623:Porphobilinogen Synthase