We examined the acute toxicity of depleted
uranium (DU) after
subcutaneous injection as a simulated
wound model (experiment I), and the effects of a
chelating agent, catechol-3,6-bis(methyleiminodiacetic acid) (
CBMIDA), on the removal and damages caused by
uranium by local treatment for
wounds in rats (experiment II). Experiment I: To examine the initial behavior and toxicity of
uranium of different chemical forms, male Wistar rats were subcutaneously injected with 4 and 16 mg kg-1 DU in a
solution of pH 1 and 7. The rats were killed 1, 3, 6, and 24 h after DU injection. The DU (pH 1) injection site on the skin was altered markedly by
acid burn, and the
chemical action of
uranium compared with that of DU (pH 7). After the injection of 4 mg kg-1 DU (pH 1), about 60% of the
uranium was retained 1-3 h at the injected sites and then decreased to 16% at 24 h. However, the concentration of
uranium in the injected site after 16 mg kg-1 DU (pH 1) injection did not change significantly. Urinary excretion rates of
uranium (pH 1) increased in a time-independent manner after the injection. Depositions of
uranium in the liver, kidneys and femur were found at 1 h after DU injection, and the results of serum and urinary examinations indicated that severe damage in the organs, including the kidney, was induced. The results of the DU (pH 7) were useful for estimating the chemical toxicity of
uranium. Experiment II: The effects of
CBMIDA by local treatment for
wounds with DU were examined.
CBMIDA (480 mg kg-1) was infused into the DU-injected site 0, 10, 30, 60, 120 min, and 24 h after the
subcutaneous injection of 4 mg kg-1 DU (pH 1 and 7). The
uranium at the injected sites decreased to 4-17% of that at 24 h in the DU (pH 1) group without
CBMIDA treatment in experiment I, when it was administered within 120 min after DU injection. In addition,
CBMIDA had excellent efficacy in excreting the
uranium in urine and feces and decreasing the concentrations of
uranium in the kidneys and femur. However, there were no distinct effects of
CBMIDA for DU (pH 7). In conclusion, the results indicated that the subcutaneous injected
uranium acutely induced severe damage in the DU-injected sites and organs by chemical toxicity within a very short time after DU intake, despite the chemical forms of
uranium used, and the local treatment of
CBMIDA for
wounds contaminated with DU was effective in decreasing the acute toxicity of
uranium if carried out within 120 min after DU administration.