Distribution of nanomole quantities of 235U in young and adult Japanese quail and in the F1 generation. Comparison with 153Gd.

Enriched uranium, 93.16% for 235U, served as a tracer of uranium deposition in an avian species, the Japanese quail. A second label, 153Gd, provided for monitoring of procedures and for estimation of the 235U content of live eggs. Depositions of 235U were greater than for 153Gd in all tissues except the yolk sac and the liver. Skeletal levels for 235U were age- and sex-dependent. Feathers contained only 0.11% of the 235U tracer in contrast to 50% of the endogenous uranium. The results show that 235U provides for tracing uranium metabolism in small animals, since in quail the tracer increased the uranium burden of the body by only 1-8%.