Lower efficiency of DTPA in reducing cadmium retention in suckling rats.

The influence of age on the effectiveness of chelation therapy in enhancing cadmium elimination was studied in 1-, 2-, 8-, and 26-week-old rats. 115mCd was administered intraperitoneally, followed immediately and after 24 hr by an intraperitoneal injection of trisodium calcium diethylenetriaminepentaacetate (DTPA) (600 mumole/kg body wt). The whole body retention determined on the second, fourth, and sixth days of the experiment showed that DTPA greatly decreased cadmium retention in all age groups being about four times more effective in older than younger animals. Determination of 115mCd retention in the gut and organs also revealed that effectiveness of DTPA was lowest for the youngest age group and increased with increasing age. This effect of DTPA was more pronounced in the liver than in the kidney and brain in all age groups. These results indicate that age greatly influences chelation of cadmium and that age might be an important factor in chelation therapy in general.