In utero exposure to DBP stimulates release of GnRH by increasing the secretion of PGE2 in the astrocytes of the hypothalamus in the offspring mice.

Abstract

Di-n-butyl phthalate (DBP), the most commonly used plasticizer and typical endocrine disrupting chemicals (EDCs), has shown its characteristics of causing reproductive and developmental toxicity in males, while the neuroendocrine toxicity induced by DBP exposure in utero and the mechanism beneath still remain unclear. Here, the pregnant mice were treated with corn oil (control) or DBP at three different doses by oral gavage during gestational days (GD) 12.5-21.5. The results showed that in utero exposure to DBP induced a significant increase of gonadotropin releasing hormone (GnRH) content in serum, as well as activation and proliferation of astrocytes in the hypothalamus of offspring male mice on postnatal day (PND) 22. However, in in vitro study, mono-n-butyl phthalate (MBP), the metabolite of DBP, could not increase the release of GnRH after GnRH neurons were exposed to MBP. Further studies identified that MBP-mediated activation and proliferation of astrocytes resulted in increased secretion of prostaglandin E2 (PGE2), which might be responsible for the increased release of GnRH from GnRH neurons. This study highlights the neuroendocrine toxicity of current plasticizer DBP exposure, laying the foundation for identifying potential molecular targets for related diseases.