The results obtained in PhD student Maria Hultman’s work have shown indication of similarities between the two hepatic exposure models, in vivo (whole fish exposures) and in vitro (primary liver cells) when using fish. The main focus has been on characterizing and understanding the estrogen responses in the two experimental models (in vitro and in vivo) when exposed to estrogenic compounds. The results have shown that key biomarker genes are similarly induced in both models, thus suggesting a well-functioning estrogen cellular response, but the in vitro methods does not seem to accommodate the complexity of endocrine regulation in vivo.
Maria’ s work is a part of NIVA`s effort to implement the 3R’s (Replacement, reduction and refinement) in ecotoxicological testing of both single chemicals (alterREACH) and mixtures of chemicals (MixTox).
Neus' main contribution has been focused on ensuring an efficient strategy for the selection of chemicals for in vitro testing with regard to acute and chronic toxicities and bioaccumulation.
Firstly, a compilation of experimental (in vivo) data for bioaccumulation was made from publicly and privately available databases. Appropriate information was identified to form a global database, where the selection of a subset of chemicals will be made according to established criteria. The aim of this selection is to conduct two in vitro methods (rt S9 and rt hepatocytes cells) to determine bioconcentration of chemicals including metabolic biotransformation information. Finally, in vivo-in vitro data integration will be made to pursue the implementation of non-animal testing methods to determine bioconcentration potential of the chemicals.