14C leucine uptake in rat tissues at different times after irradiation

The uptake of 14C leucine administered at different intervals after irradiation, but always 4 and 8 h before the animals were killed, has been evaluated in tissues with different proliferative activity and protein synthesis. The results have demonstrated an increased uptake and a more rapid elimination of the tracer after irradiation. In the small intestine a lower amount of TCA insoluble fraction was observed when the morphologic injury was evident, while protein synthesis significantly increased during the initial phase of appearance of the injury and mainly during the recovery phase of epithelial cells. Kidney and plasma had levels higher than controls at all intervals.