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(W/EH033) Evaluation of the potential hazard of the contaminants in a German river using a combination of chemical and biological methods: IV. Embryotoxicity, teratogenicity and estrogenicity. Pfluger, Paul1,2, OŽBrien, Evelyn1,2, Prietz, Anke2, Schmid, Tobias1, Heussner, Alexandra1, Dietrich, Daniel1,2, 1 2 ABSTRACT- Many xenobiotics regularly detected in river water are known to negatively affect aquatic species, e.g. by a dysregulation of the hormone system or by direct embryo- or larvae-toxicity. Especially natural and synthetic hormones have demonstrated a strong endocrine activity in several in vitro test systems (Wasserrab et al. (2000), SETAC Europe, Brighton, UK). Furthermore, various ubiquitously present compounds, e.g. diclofenac, nonylphenol, are embryotoxic in test systems e.g. DRETA (Dietrich et al (1998), Toxicol. Sci. 42(1-S): 259; Dietrich and Prietz (1999), Toxicol. Sci. 48(1-S): 151). However, to date the main part of the information available handles the effects of single chemicals rather than the potential effects of complex chemical mixtures as they are found in water samples. Therefore, the aim of this study was to investigate the estrogenic activity and embryotoxicity of 7 consecutive daily water samples. In addition, general toxicity was tested using the Daphnia sp. acute immobilization test (OECD (1984), Guideline 202). Embryotoxicity was determined by DRETA and FETAX (Frog Embryo Teratogenesis Assay Xenopus). Here, early life-stages of fish and frog were exposed to the water samples for 96h and subsequent determination of length, mortality and malformation. None of the tested water samples displayed significant embryotoxicity in either DRETA or FETAX systems, nor toxicity in the Daphnia sp. immobilization test. Estrogenicity was examined in rainbow trout (Oncorhynchus mykiss) and carp (Cyprinus carpio), using two in vitro test systems: the competitive estrogen receptor binding assay (CERBA) and the stimulation of vitellogenin and estrogen receptor at protein level (ELISA) and mRNA-level (RT-PCR) in primary hepatocytes. Key words: Embryotoxicity, Teratogenesis, Estrogen, Endocrine |
