WP9 Endocrine Disruption: Fish Estrogenicity
Room 12A/B, Level 4
2:10 PM - 5:30 PM, Wednesday, 12 November 2003
Chair: Janz, David ,
Co-chair: Foran, Christy ,
(475) A non-spawning fish assay to detect (anti-)androgens and aromatase inhibitors.
Panter, G1, Hutchinson, T1, Hurd, K1, Sherren, A2, Stanley, R1, Tyler, C3, 1 AstraZeneca Global SHE, Brixham, Devon, UK2 Shell Global Solutions, Chester, Cheshire, UK3 Exeter University, Exeter, Devon, UK
ABSTRACT- Screening assays have been successfully developed for the detection of (anti-)oestrogenic substances in several fish species, including the fathead minnow (Pimephales promelas). However, a validated screen for detecting environmental (anti-)androgens and other endocrine active substances (EACs) is lacking. Previous work suggested that non-spawning fathead minnows might provide an appropriate window for detecting these EACs. Therefore, sub-adult fathead minnows, in which their phenotypic sex could be determined, were exposed in flow-through systems to three reference substances for up to 21 days, at 25°C. Male and female fish were held in separate tanks. The chemicals chosen were dihydrotestosterone (androgen), flutamide (anti-androgen) and fadrozole (aromatase inhibitor). After 14 and 21 days exposure, fish from each treatment were sampled and evaluated for secondary sexual characteristics (SSC), gonadosomatic index (GSI) and whole-body vitellogenin (VTG) concentrations (determined by an enzyme linked immunosorbent assay). Evaluation of SSC appeared to be a rapid and sensitive endpoint for measuring (anti-)androgen exposure. Exposure to the androgen (dihydrotestosterone) induced the number of nuptial tubercles (male charactersitic) in both males (more abundant) and females. In male fish exposed to flutamide, a decline in nuptial tubercles was observed. Changes in GSI and VTG appeared to be sensitive endpoints for detecting fadrozole exposure. Fadrozole lowered female GSI but increased male GSI, this was complimented by an inhibition and induction, respectively, in plasma VTG concentrations. These data also show that fathead minnows (measuring SSC, GSI and VTG) can be used to screen for these classes of endocrine disrupting chemicals.
Key words: (anti-)androgens, fathead minnow, aromatase inhibitor