Publication Abstract

Two exposure scenarios to a mixture of endocrine disrupting chemicals using the three-spined stickleback

I. Katsiadaki*, G. Stentiford*, M. Sanders*, Y. Allen*, A.P. Scott*

The use of the stickleback as a model species in ecotoxicology and in particular chemical endocrine disruption is increasing. The stickleback offers two unique tools for the study of endocrine disrupting chemicals (EDCs), the androgen-regulated protein spiggin and the well-documented reproductive behaviour. In addition it is one of the few recognised species for testing whilst inhabiting marine environments. 

Here we describe histopathological and biomarker (vitellogenin, spiggin) responses in adult fish that were exposed over a six-month period to a model oestrogen and a model antiandrogen alone and in combination. The experiment was conducted twice. The design between the two exposures was similar but the first followed an episodic/pulse exposure whilst the second followed the more usual constant concentration exposure. During the episodic exposure the fish were initially treated with a high concentration of EDCs, which was subsequently reduced to below measured environmental levels, whilst all the concentrations used in the constant exposures were environmentally relevant and stable over time. 

The responses between the two exposure scenarios were dramatically different both in terms of biomarker data and gonadal histopathology. In addition there were signs of synergism between the two model chemicals used; fish treated with the binary mixture were more feminised than fish treated with the oestrogen alone. The findings are discussed in terms of risk assessment of endocrine active compounds in the marine environment with particular emphasis on the high antiandrogenic activity present in the oilfield produced water.

Reference

I. Katsiadaki*, G. Stentiford*, M. Sanders*, Y. Allen*, A.P. Scott*  (2009) Two exposure scenarios to a mixture of endocrine disrupting chemicals using the three-spined stickleback. PRIMO 15