Effects of uranium on reproductive function in rats exposed from fetal life to adulthood
Résumé
In the environment, uranium may be present in drinking water contaminated naturally, by military activities or by human activity in nuclear power stations, mining sites, and farmland (use of phosphate fertilizers). In epidemiological and experimental studies, few reports have clearly demonstrated the effects of environmental uranium exposure on reproductive health outcomes. Nevertheless, because uranium is a radionuclide and a heavy metal, its chemical properties are suspected to be implicated in endocrine effects at low-doses. In our study, we studied these effects on male rats after lifelong exposure to 40 and 120 mg.L-1 of depleted uranium (DU). We detected a significant content of uranium in testis, epididymis in the DU 120 mg.L-1 group and in epididymal spermatozoa in both DU groups. Despite no major testicular histological defects, intratesticular and plasma hormones were modulated and associated with modification of several genes specific to steroidogenesis and spermatogenesis. Interestingly, plasma levels of pituitary hormones (FSH, LH) were induced only in DU 120 mg.L-1. In conclusion, we show that fetal life is a critical window for chronic uranium exposure. We evidenced that the endocrine activities of low-dose uranium could disrupt steroidogenesis through the hypothalamic-pituitary-testicular axis, particularly in 120 mg.L-1 group. In order to contribute in risk assessment of uranium exposure, further experimental studies are needed to identify the effects on reproductive function and epigenetic profile on the next generations.
Origine : Fichiers produits par l'(les) auteur(s)
Licence : CC BY NC ND - Paternité - Pas d'utilisation commerciale - Pas de modification
Licence : CC BY NC ND - Paternité - Pas d'utilisation commerciale - Pas de modification