Di-(2-ethylhexyl) phthalate (DEHP) interferes with male reproductive endocrine system in mammals, however its effects on fish reproduction are largely unknown. We evaluated sperm quality and investigated reproductive endocrine system in mature goldfish (Carassius auratus) exposed to nominal 1, 10, and 100μg/L DEHP. To examine DEHP estrogenic activity, one group of goldfish was exposed to 17β-estradiol (5μg/L E2) for comparison. Following 30d of exposure, sperm production was decreased and suppressed in DEHP and E2 treated goldfish, respectively. Sperm motility and velocity were decreased in goldfish exposed to 100 and 10μg/L DEHP at 15s post-sperm activation, respectively. Compared to control, 11-ketotestosterone (11-KT) levels were decreased at 10 and 1μg/L DEHP at day 15 and 30, respectively. In E2 treated goldfish, 11-KT levels were decreased compared to control during the period of exposure. E2 levels were increased in goldfish exposed to E2, but remained unchanged in DEHP treated goldfish during the period of exposure. StAR mRNA levels encoding regulator of cholesterol transfer to steroidogenesis were decreased in DEHP and E2 treated goldfish following 15 and 30d of exposure, respectively. Luteinizing hormone (LH) levels were decreased in DEHP and E2 treated goldfish following 15 and 30d of exposure, respectively. In DEHP treated goldfish, gnrh3, kiss1 and its receptor (gpr54) mRNA levels did not change during the experimental period. In E2 treated goldfish, gnrh3 mRNA levels were decreased at day 7, but kiss1 and gpr54 mRNA levels were increased at day 30 of exposure. The mRNA levels of genes encoding testicular LH and androgen receptors remained unchanged in DEHP and E2 treated goldfish. In contrast to E2 treated goldfish, vitellogenin production was not induced in DEHP treated goldfish and mRNA levels of genes with products mediating estrogenic effects remained unchanged or decreased. In conclusion, DEHP interferes with testis and pituitary hormonal functions to reduce sperm quality in goldfish and does not exhibit estrogenic activity.

Department of Ichthyobiology and Fisheries University of Agriculture Kraków Poland

Department of Marine Sciences Polytechnic University of Marche Ancona Italy

Department of Veterinary Sciences Faculty of Agrobiology Food and Natural Resources Czech University of Life Sciences Prague Czech Republic; Research Institute of Fish Culture and Hydrobiology South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses Faculty of Fisheries and Protection of Waters University of South Bohemia Vodňany Czech Republic

National Institute of Aquatic Resources Technical University of Denmark Charlottenlund Denmark

Research Institute of Fish Culture and Hydrobiology South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses Faculty of Fisheries and Protection of Waters University of South Bohemia Vodňany Czech Republic

Research Unit Animal and Functionalities of Animal Products University of Lorraine Nancy France

Veterinary Biomedical Sciences Department Western College of Veterinary Medicine University of Saskatchewan Saskatoon Saskatchewan Canada; Research Institute of Fish Culture and Hydrobiology South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses Faculty of Fisheries and Protection of Waters University of South Bohemia Vodňany Czech Republic

References provided by Crossref.org

A Review on Environmental Contaminants-Related Fertility Threat in Male Fishes: Effects and Possible Mechanisms of Action Learned from Wildlife and Laboratory Studies