The lead-chelating effects of substituted dithiocarbamates

The effectiveness of certain substituted dithiocarbamates in mobilizing lead from preexposed rats was investigated. The animals received 10 mg Pb/kg/day, intragastrically, for 8 weeks and were treated thereafter with 400 mumol/kg, intraperitoneally, of morpholine dithiocarbamate, tetraammonium ethylenediamine diacetic acid dithiocarbamate (EDDTC), ammonium diethanolamine dithiocarbamate (ADDTC), sodium diethyldithiocarbamate, N-benzyl-D-glucamine dithiocarbamate (NBGDTC), or dimercaptosuccinic acid, daily for 5 days. All the chelating agents were effective in lowering the hepatic and renal burden of Pb. ADDTC, EDDTC, and NBGDTC were also able to lower the long bone Pb content. The lowering of Pb burden had no relationship to restoration of Pb-induced hematopoietic alterations. The relatively lower lipophilicity of substituted dithiocarbamates, owing to the presence of hydrophilic groups, seems to be advantageous in preventing passage of metal chelate into the brain. None of the substituted dithiocarbamates caused excessive excretion of urinary Cu and Zn. ADDTC and EDDTC appear to be promising in the management of Pb poisoning.