COMBINED CHELATION TREATMENT FOR POLONIUM AFTER SIMULATED WOUND CONTAMINATION IN RAT

Contaminated puncture wounds were simulated in rat by intramuscular in jection of Po-210. The aim of the study was to determine the effective ness of chelation treatment as a function of time, dosage, and route o f chelate administration. Ten newly synthesized substances containing vicinal sulphydryl and carbodithioate groups were used and their effec t was compared with that of chelators clinically applicable in man-BAL (2,3-dimercaptopropane-1-ol), DMPS (2,3-dimercaptopropane-1-sulphonat e), DMSA (meso-2,3-dimercaptosuccinic acid), and DDTC (sodium diethyla mine-N-carbodithioate). The results indicate first that complete remov al of Po-210 from the injection site is achieved by only two local inj ections of DMPS, beginning as late as 2 h after injection of Po-210. S econd, many of the substances used merely induce translocation of Po-2 10 from the injection site into other tissues. Third, a combined local treatment at the injection site with DMPS plus repeated systemic, sub cutaneous, treatments with HOEtTTC roxyethyl)ethylenediamine-N,N'-bisc arbodithioate), a derivative of DDTC, results after 2 weeks in a reduc tion of the estimated total body retention of Po-210 to about one-thir d of that in untreated controls. In the latter case the cumulative exc retion of Po-210 increased from 8 to 54%, mainly via the faeces.