COMPARATIVE-EVALUATION OF CHELATING-AGENTS ON THE MOBILIZATION OF CADMIUM - A MECHANISTIC APPROACH

A comparative evaluation of chelating agents, namely, diethyl dithioca rbamate (DDC) dimethyl dithiocarbamate (DMDC) 1,4,8,11-tetraazacyclote tradecane (CYCLAM) 1,4,8,12-tetraazacyclopentadecane (TACPD) 2,3-dimer captosuccinic acid (DMSA) and 2,3-dimercapto-1-propane sulfonate (DMPS ) was conducted to assess their efficacy against acute cadmium (Cd) to xicity. DMSA and DMPS appeared to be most effective in reducing mortal ity as well as Cd burden of liver, kidneys, and brain in cadmium intox icated mice. DMDC reduced Cd levels only in liver and kidneys, while D DC significantly enhanced its level in brain. CYCLAM and TACPD signifi cantly increased the Cd level in liver and kidneys and were ineffectiv e in brain. The therapeutic index as well as therapeutic efficacy was highest for DMSA followed by DMPS and DMDC. A fair degree of correlati on was found to exist between (I) stability constant of Cd chelates an d percent survival (r = .438), (2) stability constant and percent tran sport (r = .479), and (3) percent survival and percent transport (r = .447). However, the lipophilicity did not show any appreciable correla tion with percent survival and stability constant of Cd chelates.