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

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 ( Oryzias latipes ). 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 ( chgH ) and vitellogenin ( vtg ) 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 ( kiss ), gonadotropin-releasing hormone ( gnrh ), and follicle-stimulating hormone beta ( fshβ ) 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.