Zebrafish, a promising model to screen for environmental exposure

Oral/Poster ZEBRAFISH, A PROMISING MODEL TO SCREEN FOR ENVIRONMENTAL EXPOSURE Didima De Groot1*, Roderick Slieker1, Celine De Esch1, Marlies Otto1, Cor Snel1, Aswin Menke1, Andre Wolterbeek1, Jan Langenberg2 1 2

TNO, Zeist, The Netherlands TNO, Rijswijk, The Netherlands

Practical and reliable screening methods for unknown toxicity of chemical compounds in vivo are not available for ‘field work’; e.g. environmental disaster or battle field objectives, where advanced laboratories are not available and information about risks to environmental exposure is urgently required. So far, for complex endpoints like reproduction and developmental toxicology animal-free in vitro models are limited and cover only a restricted part of the reproductive cycle. Various characteristics warrant Zebrafish (embryos and/or larvae) an ideal non-mammalian whole organism model that could bridge gaps between in vitro (stem) cell systems and complex reproduction studies in vivo in mammals, e.g. small size, ease of obtaining a high number of progeny, external fertilization, transparency and rapid development of the embryo, and a basic understanding of its gene function and physiology. Here we look at the zebrafish as a model for the purposes mentioned. Hereto, we administered five toxic model compounds in different concentrations: CuSO4, ZnSO4, MeHg, DCP and permetrin and looked at embryotoxicity, hepatotoxicity and motor activity. The usefulness of the parameters obtained from motor activity were questioned and, therefore, we looked at the value of these parameters for toxicity testing in this study. Results demonstrate that the zebrafish is a practical and reliable screening model for the intended use. In embryotoxicity EC50s were calculated and increased number of unhatched eggs was observed together with dose dependent increase in coagulation and other abnormalities. Regarding motor activity, the duration of movements and velocity appeared to be inaccurate measures. The distance moved appeared to be more sensitive to detect toxic effects. In distance moved, hypoactivity was observed in the CuSO4, DCP, ZnSO4 treated zebrafish in a significant dose dependent manner (ANOVA, p