Simultaneous reduction of radioactive strontium, caesium and iodine retention by single treatment in rats.

The effect of a mixture of calcium alginate, iron (III) ferrocyanide and potassium iodide added to rat diet on 85Sr, 137Cs and 131I metabolism and health was investigated in female rats after four weeks of treatment. The retention of these radioisotopes was determined in the whole body and critical organs six days after 85 Sr and 137CS and one day after 131I oral administration. The health effect of the mixture was evaluated by measuring body weights, haematological parameters, concentrations of iron, zinc and manganese in the kidneys, liver and femur, bone parameters (femur composition and morphometry) and by a histopathological examination. The mixture reduced 85Sr retention in the femur 11 times, 137Cs retention in the thigh muscle 102 times and 131I retention in the thyroid 134 times. Treated animals were in good health and the only differences found between the control and experimental rats were slightly lower haemoglobin values in the blood and a slightly lower iron concentration in the liver. It is concluded that the mixture was very efficient for decreasing body retention of three important fission products and that it can be used over long periods without causing adverse health effects.

The influence of age on the efficiency of delayed therapy with Ca-DTPA for cerium in rats.

The influence of age on the effectiveness of chelation therapy starting 24 h after cerium administration was studied in 2- and 6-week-old rats. 141Ce was administered IP, followed after 24 and 48 h by IP administration of trisodium calcium diethylenetriaminepentaacetate (Ca-DTPA). The whole body and organ retention of 141Ce was determined 6 days after its administration. The chelation therapy significantly reduced cerium retention in both age groups but was more efficient in older animals. This age-related effect was, however, less pronounced than after immediate treatment with DTPA observed in our previous experiments, indicating that age as one of the factors which influence the efficacy of chelation treatment is probably more important in conditions of early than in conditions of delayed therapy.

Effect of milk on mercury absorption and gut retention in rats.

The retention of 203Hg was studied six days after a single oral or intraperitoneal administration to six week old female albino rats fed rat's diet or milk. After oral administration rats on milk diet had a two times higher retention of mercury in the gut-free carcass and a 23 times higher retention in the gut than animals on rat's diet. Changes in diet had very little influence on mercury retention after intraperitoneal administration. The higher gut and carcass rentions of mercury in animals on milk diet could be prevented or reduced by transferring rats from milk diet to rat's diet several days after an oral dose of mercury. These results might be relevant for interpreting high gut and carcass retention after oral administration of some metals in suckling and changes which occur at weaning.