Di-n-butyl phthalate causes antiestrogenic effects in female murray rainbowfish (Melanotaenia fluviatilis)

Di-n-butyl phthalate (DnBP) is an industrial pollutant with antiandrogenic effects reported in male mammals and fish. Little research has been done on the endocrine effects of DnBP in female fish. The present study investigated the changes in ovarian histology and serum vitellogenin concentrations in adult Murray rainbowfish (Melanotaenia fluviatilis) after exposure to 125 mu g/L, 250 mu g/L, 500 mu g/L, and 1000 mu g/L DnBP for 7 d. Treatment at 125 mu g/L to 1000 mu g/L DnBP for 7 d had no significant effect on the survival, condition factor, gonadosomatic index, hepatosomatic index, and developmental stage of the fish. Based on the histological investigation, the sizes of the previtellogenic oocytes in the fish treated at 250 mu g/L to 1000 mu g/L were found to be significantly higher than in the corresponding control fish (p 0.05). The early vitellogenic oocytes in the fish treated at 1000 mu g/L were significantly smaller relative to those in the unexposed fish (p 0.05). Histological changes like chorion folding, shrunken ooplasm, impaired yolk production, granulomatous inflammation, and interstitial fibrosis were observed in the ovaries of the fish treated with DnBP. The circulating levels of plasma vitellogenin were significantly lower in the fish exposed to 500 mu g/L and 1000 mu g/L DnBP (p 0.05). These data show that a continuous exposure to subacute concentrations of DnBP for 7 d can cause antiestrogenicity in female adult Murray rainbowfish. Environ Toxicol Chem 2013;32:2335-2344. (c) 2013 SETAC