The Reproductive Effects in Rats after Chronic Oral Exposure to Low-dose Depleted Uranium

This two-generation study evaluated the effects of depleted uranium (DU) on reproduction in rats. Across two generations, Wistar rats (30/sex/group) were maintained on feed containing DU at dose levels of 0 (control group), 4 (DU₄ group), or 40 (DU₄₀ group) mg kg⁻¹ day⁻¹ for 4 months prior to mating. After 4 months of exposure, the pregnancy rate, normal labour rate, and survival rate of offspring produced by F₁ rats were all significantly decreased as compared to the control group, and especially in the DU₄₀ group, these parameters fell by half to two-thirds, while no adverse effects were evident in F₀ rats. The uranium content in the testes and ovaries of F₁ rats in the DU₄ and DU₄₀ groups was significantly higher than that found in F₀ rats. The levels of sex hormone in the serum were disorder in both generations. The enzymes related to spermiogenesis were also significantly different between generations, and the damage was more severe in F₁ rats. In conclusion, the reproductive effects in F₀ rats were slight after chronic oral exposure to DU, while the effects were obvious in F₁ rats.