PARENT SESSION

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

(WEP/94) Endocrine disruption in the nematode Caenorhabditis elegans.

Weltje, Lennart¹, Höss, Sebastian², van Doornmalen, Jacco¹, Markert, Bernd¹, Oehlmann, Jörg³, ¹ International Graduate School (IHI), Zittau, Germany, Germany² Ecossa, Munich, Germany, Germany³ J.W. Goethe University, Frankfurt, Germany, Germany

ABSTRACT- The nematode Caenorhabditis elegans was used to assess the endocrine disrupting potential of twelve substances in water. It concerns: 17-ethynylestradiol, tamoxifen, cyproterone acetate, 17-methyltestosterone (pharmaceuticals), vinclozolin, precocene II, fenarimol, methoprene (pesticides), butylbenzylphtalate, 4-n-octylphenol (industrial chemicals), and two naturally-occurring compounds: luteolin and 20-hydroxyecdysone. Nematodes were exposed at concentrations ranging from 0.1 to 1,000 nM at 20°C for 96 h. The endpoints determined were fertility (percentage of gravid adults), reproduction and growth. All animals were gravid, but reproduction and growth showed distinct differences between substances. Reproduction was stimulated by eight substances, while the other four substances had values comparable to those of the control. Five substances reduced growth significantly and six substances had no effects on growth. Only in the case of precocene II, a significant stimulation of growth was observed at low concentrations, whereas growth was reduced at higher concentrations. Often an exchange between growth and reproduction was found, which suggests that the nematodes in our test system had a limited energy budget at their disposal. It appears that stimulation of reproduction is a suitable endpoint for the detection of estrogenic or anti-androgenic effects.

Key words: endocrine disruption, Caenorhabditis elegans, reproduction, growth