In vitro effects of Uranium on human fetal germ cells.

Uranium (U) is found in the environment and its use in industrial or military activities has led to concerns about its potential toxicity. The reprotoxicity of this heavy metal has been established in adult animals; however, no studies have examined its effect on human fetal gonads. Using an organ culture system, we investigated the effects of uranyl acetate on human gonads during the first trimester of gestation (7-12 weeks), which is a critical step in the development of a functional reproductive system. In human fetal ovaries, 0.05 mM U significantly decreased germ cell density by increasing their apoptosis rate. In human fetal testes, 0.1mM U similarly reduced the number of germ cells. The human fetal germ cells are more sensitive to U than mouse germ cells in the same experimental conditions. This is the first evidence that U may impair the development of the human gonads.