The Behaviour of Uranium-233 Oxide and Uranyl-233 Nitrate in Rats

Summary

²³³UO₂ and ²³³UO₂(NO₃)₂ in aqueous suspension have been administered to rats by pulmonary intubation. The ²³³U associated with the fraction of the ²³³UO₂ less than 4 nm in diameter translocates from lungs to blood at the same rapid rate as ²³³U from ²³³UO₂ (NO₃)₂. Identical reactions with blood plasma and lung fluid were observed whether the ²³³U was administered as <4nm ²³³UO₂ particles or ²³³UO₂(NO₃)₂. It is suggested that oxidation of UO₂ to UO₃ occurs followed by the formation of uranyl ion. In blood plasma, approximately 50 per cent of the ²³³U is bound to transferrin, 25 per cent to citrate and 25 per cent on bicarbonate.