Effects of D-penicillamine and Ca-DTPA on Removal of Radiocobalt in Rats

Based on a medical treatment schedule for humans, the effects of D-penicillamine and Ca-DTPA on the removal of radiocobalt were examined in rats. Rats were pre-injected with radiocobalt and then treated with D-penicillamine alone via oral route, Ca-DTPA alone via intraperitoneal injection, or both compounds at the same time at doses equivalent to the daily recommended human dose. The compounds were administered for 3 days, beginning with or 1h after radiocobalt injection at the first day. The radioactivity levels of the whole body of rat, urine and feces were measured at intervals of 24h. On day 4, the rats were sacrificed in order to obtain blood and organs. When D-penicillamine was administered with and 1h after injection of radiocobalt, the whole body activity was reduced to 9.6 and 79.0% of that of the control, respectively, in the Ca-DTPA-alone groups and to 54.8% in the group in which both compounds were administered 1h after radiocobalt. In the D-penicillamine-alone groups, the activity levels were reduced to 33.6 and 56.6% with and 1h after radiocobalt injection, respectively. In conclusion, the results of this study indicate that D-penicillamine is useful in treating a person contaminated with radiocobalt in an accident.