Distribution of uranium in rats inhaled with depleted uranium aerosols

Objective: To investigate the distribution of uranium in rats after inhalation with depleted uranium aerosols. Methods: The depleted uranium aerosols were inhaled by Wistar rats. At 30, 90, 180, 270, 360, and 540 d after inhalation, the rats were sacrificed and tissue samples were collected. The contents of uranium in lung, kidney, liver, heart, brain, thighbone, spleen and thymus were measured by laser time- dependent spectroscopy analysis. Results: The uranium contents of lung increased in the high-dose and low- dose groups [(499 833.3 ± 14 214.8) ng/g and (25 424.0 ± 6193.4) ng/g, respectively] after inhalation, and significantly differed from the control (28.8 ± 13.9)ng/g, (P<0.05). At 30 d after inhalation, the contents of uranium in lung, kidney and thighbone were higher than those of control, and then decreased time-dependently. At 60 d, the contents of uranium in liver, heart, brain, spleen and thymus were higher than those of control. Curve of the contents were biphasic, which went up first, reached at peak value and then went down. The contents of uranium were high in lung, thighbone, brain and thymus. Conclusions: After inhalation of depleted uranium aerosols, lung and thighbone are the primary reservoirs for uranium redistributed, and accumulations in brain and thymus suggest other two organs for unanticipated injury by depleted uranium. (authors)