title: Estrogenic effect of propylparaben (propylhydroxybenzoate) in rainbow trout Oncorhynchus mykiss after exposure via food and water.
abstract: The estrogenic effect of propylparaben was investigated in a rainbow trout Oncorhynchus mykiss test system. Propylparaben was administered orally to sexually immature rainbow trout every second day for up to 10 days in doses between 7 and 1830 mg kg(-1) 2 d(-1) and in the water at 50 and 225 microg l(-1) for 12 days. Plasma vitellogenin was measured before and during the exposures and the concentrations of propylparaben in liver and muscle were determined at the end of experiments. Increases in average plasma vitellogenin levels were seen at oral exposure to 33 mg propylparabenkg(-1) 2 d(-1); the most sensitive fish responded to 7 mg kg(-1). The ED(50) values for increase in vitellogenin synthesis were 35, 31 and 22 mg kg(-1) 2 d(-1) at day 3, 6 and 11, respectively. Exposure to 225 microg propylparabenl(-1) increased vitellogenin synthesis, but exposure to 50 microg l(-1) did not. Propylparaben showed little tendency to bioaccumulation in rainbow trout; less than 1 per thousand of the total amount of propylparaben administered orally at 1830 mg kg(-1) 2 d(-1) over the 10-d experimental period was retained in muscle and liver 24 h after the end of the experiment. Exposure to 225 microg propylparabenl(-1) for 12 d led to concentrations of 6700 and 870 microg propylparabenkg(-1) liver and muscle, respectively. Half lives for propylparaben were 8.6 h in liver and 1.5 h in muscle.
authors.affiliation: Institute of Biology, University of Southern Denmark, Odense, Campusvej 55, DK-5230 Odense M, Denmark. poul@biology.sdu.dk
authors.forename: Poul
authors.initials: P
authors.lastname: Bjerregaard
authors.forename: Dorthe N
authors.initials: DN
authors.lastname: Andersen
authors.forename: Knud L
authors.initials: KL
authors.lastname: Pedersen
authors.forename: Søren N
authors.initials: SN
authors.lastname: Pedersen
authors.forename: Bodil
authors.initials: B
authors.lastname: Korsgaard
mesh_terms: D000284:Administration, Oral; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004968:Estrogens, Non-Steroidal / Q000008:administration & dosage*; D005260:Female; D006207:Half-Life; D007700:Kinetics; D008099:Liver / Q000737:chemistry; D008297:Male; D018482:Muscle, Skeletal / Q000737:chemistry; D017686:Oncorhynchus mykiss / Q000502:physiology*; D010226:Parabens / Q000008:administration & dosage*; D014819:Vitellogenins / Q000097:blood; D014867:Water / Q000008:administration & dosage*
chemical_list: D004968:Estrogens, Non-Steroidal; D010226:Parabens; D014819:Vitellogenins; D014867:Water; C006068:propylparaben