Publication Abstract

Simultaneous assessment of oestrogenic and (anti)-androgenic effects using the three-spined stickleback

Ioanna Katsiadaki

We have previously shown that exposure to exogenous androgens causes female sticklebacks (Gasterosteus aculeatus) to produce the glue protein, spiggin, in their kidneys. This protein can be quantified by an enzyme-linked immunosorbent assay (ELISA), which was developed and validated in CEFAS. More recently we reported the development of a procedure for quantifying the oestrogen-induced egg yolk protein (vitellogenin, VTG), in either whole body, heart or liver extracts of the stickleback. The results of two experiments in which sticklebacks were exposed to several different doses of ethinyl oestradiol indicated that the procedure can be used to evaluate the effects of oestrogenic endocrine disrupters in the aqueous environment. The simultaneous exposure of female stickleback to a model androgen, 17a-methyltestosterone (at 0.5µg/l), and environmental anti-androgens resulted in total inhibition or lower spiggin production, when compared female fish solely exposed to the model androgen. All fish were exposed over a period of 21 days under semi-static conditions. The assay detected the anti-androgenic activity of flutamide, vinclozolin (both used at 250µg/l), linuron (at 150µg/l) and fenitrothion (at 15µg/l and 150µg/l). These results provide the first evidence of in vivo anti-androgenic activity of both linuron and fenitrothion in teleosts. In addition, the results suggest the three-spined stickleback is more sensitive than other proposed test species in detecting the antiandrogenic activity of flutamide and vinclozolin. Although there are many other fish species that can be used for this purpose, the stickleback is the only widely-available species in which it is now possible to study both oestrogenic and (anti)-androgenic endpoints in the same individual. Furthermore, the species is endemic and ubiquitous in Europe and possesses many ecological traits that make it better suited than other potential species for field research into endocrine disruption

Reference:

Ioanna Katsiadaki. 2004. Simultaneous assessment of oestrogenic and (anti)-androgenic effects using the three-spined stickleback. UK-Japan Workshop on endocrine disrupters, 19 February 2004, Kumamoto, Japan