Abstract
The experiment was performed in order to investigate the intestinal retention and absorption of radiocerium in juvenile beagles and the result was compared with that obtained previously in the rat. 141Ce given orally was retained in the whole-body for more prolonged time by suckling than by weanlings or adults. Distribution study showed that the 141Ce was associated with the intestinal tract and a little was transferred to the organs other than the intestine. The present result was in accord with that in rats qualitatively. However, there are important differences of the 141Ce metabolism between beagles and rats which affects the intestinal dose calculation. The retention curve of 141Ce for beagle sucklings can be described exponentially and the levelling off of whole-body 141Ce retention occurs before the time of weaning, while the curve for rat sucklings has a so-called shoulder and the levelling off takes place at about weaning.
