PARENT SESSION

2L - Immunotoxicity - genotoxicity - ED
Poster Hall
8:30 AM - Wednesday, 30 April 2003
Chair: Hansen, P.D.¹, ¹

(WEP/124) Endocrine disruption in the hermaphroditic freshwater pondsnail Lymnaea stagnalis.

Weltje, Lennart¹, Scholz, Conny¹, van Doornmalen, Jacco¹, Markert, Bernd¹, Oehlmann, Jörg², ¹ International Graduate School (IHI), Zittau, Germany² J.W. Goethe University, Frankfurt am Main, Germany

ABSTRACT- The common freshwater pondsnail Lymnaea stagnalis was exposed to pharmaceuticals (17-ethynylestradiol, tamoxifen, cyproterone acetate and 17-methyltestosterone) and fungicides (vinclozolin and fenarimol); chemicals known for their potential to disrupt endocrine functions in organisms. Since L. stagnalis is a simultaneous hermaphrodite, i.e. both sexual functions are active at the same time, targets for both (anti-)estrogenic and (anti-)androgenic substances are present within one organism. This presents an interesting challenge, because the possibility of masking subtle effects of a substance is apparent. Different exposure regimes were used to assess if the chosen substances induced endocrine effects in the snails. Concentrations in the nanomolar range were applied to freshly laid eggs and the time it took for a juvenile to emerge from the egg was recorded. Furthermore, freshly hatched juvenile snails were exposed until adulthood was reached and their subsequent egg production was recorded. Also, the viability of the produced eggs was assessed. It appeared that fenarimol, as well as certain combinations of pharmaceuticals, exposed over the entire lifetime of the snail, delayed the onset of egg production and lowered the egg production rate.

Key words: pharmaceuticals, pesticides, freshwater, invertebrate