Influence of phthalate and non-phthalate plasticizers on reproductive endocrine system-related gene expression profiles in Japanese medaka ().

Plasticizers containing phthalates have the potential to alter endocrine function in vertebrates. While non-phthalate plasticizers were previously considered to be environmentally friendly and safe, our research team discovered that bis-(2-ethylhexyl) adipate (DEHA) and acetyl tributyl citrate (ATBC) disrupt thyroid hormones in Japanese medaka (). We assessed reproductive- and estrogen-responsive gene expression patterns in Japanese medaka to determine whether the phthalate plasticizers bis-(2-ethylhexyl) phthalate (DEHP, positive control) and the non-phthalate plasticizers DEHA and ATBC disrupt endocrine signaling. The results showed that the levels of choriogenin H () and vitellogenin () genes increased after exposure to DEHP and ATBC, suggesting that these plasticizers may have estrogenic activity. Exposure to DEHP and DEHA resulted in the upregulation of kisspeptin (), gonadotropin-releasing hormone (), and follicle-stimulating hormone beta () genes, suggesting that these plasticizers may interfere with reproductive function. To the best of our knowledge, this is the first study to demonstrate that the non-phthalate plasticizers DEHA and ATBC can disrupt reproduction-related hormonal activity in fish.