Combined Chelation Treatment for Polonium after Simulated Wound Contamination in Rat

Abstract

Contaminated puncture wounds were simulated in rat by intramuscular injection of ²¹⁰Po. The aim of the study was to determine the effectiveness of chelation treatment as a function of time, dosage, and route of chelate administration. Ten newly synthesized substances containing vicinal sulphydryl and carbodithioate groups were used and their effect was compared with that of chelators clinically applicable in man—BAL (2,3-dimercaptopropane-1-ol), DMPS (2,3-dimercaptopropane-l-sulphonate), DMSA (meso-2,3-dimercaptosuccinic acid), and DDTC (sodium diethylamine-N-carbodithioate). The results indicate first that complete removal of ²¹⁰Po from the injection site is achieved by only two local injections of DMPS, beginning as late as 2 h after injection of ²¹⁰Po. Second, many of the substances used merely induce translocation of ²¹⁰Po from the injection site into other tissues. Third, a combined local treatment at the injection site with DMPS plus repeated systemic, subcutaneous, treatments with HOEtTTC (NN'-di-(2-hydroxyethyl)ethylenediamine-NN'- biscarbodithioate), a derivative of DDTC, results after 2 weeks in a reduction of the estimated total body retention of ²¹⁰Po to about one-third of that in untreated controls. In the latter case the cumulative excretion of ²¹⁰Po increased from 8 to 54%, mainly via the faeces.