Dietary treatment for decreasing 141Ce body burden in immature rats.

The purpose of this work was to evaluate the effect of prolonged (immediate or delayed) administration of dietary additives to suckling rats on the absorption and retention of radioactive cerium in the body. The experiment was performed on 6-day-old suckling rats. According to dietary treatment the animals were divided into three groups. Each group was artificially fed over 8 h for 6 or 12 days on one of the diets: the first group of animals was fed milk, the second group was given ingredients of rat diet and the third received milk during the first 2 days of the experiment and the ingredients of rat diet afterwards. At the end of the artificial feeding period the pups returned to their mothers and suckled overnight. On the 1st day of the experiment the food was labelled with 141Ce. Whole body radioactivity was determined in a double crystal scintillation counter every 48 h over a 12-day period. Half of the animals from each group were killed 6 days after 141Ce administration and the other half after 12 days. At these intervals retention was determined in the gut, liver, kidneys and femur. The early and delayed administration of rat diet ingredients--fish meal, sunflower meal, alfalfa, cane molasses and premix--greatly reduced whole body retention. The early treatment was more efficacious than the delayed one. The reduction was mostly due to decreased gut retention but organ retentions were also lower. The results obtained indicate that by prolonged (immediate or delayed) administration of some dietary means the retention of radioactive cerium in sucklings can be significantly decreased.