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(18-35) The testosterone metabolism of Neomysis integer: the quest continues... Verslycke, Tim*,1, De Wasch, Katia2, Janssen, Colin1, De Brabander, Hubert2, 1 Laboratory of Environmental Toxicology and Aquatic Ecology, Ghent, -2 Laboratory of Chemical Analysis, Merelbeke, - ABSTRACT- Both vertebrate and invertebrate species use enzymatic biotransformations for the detoxication and elimination of xenobiotics. Testosterone has been used as a substrate to study the multiplicity of these enzymes. Since many of these enzymes are hormonally controlled, disruption of the hormone function can lead to potential effects on enzyme function and steroid homeostasis. The testosterone metabolism has therefore been proposed as a biomarker of exposure to endocrine disruptive compounds. Neomysis integer (Crustacea; Mysidacea) not only metabolises testosterone extensively, we also reported the first study on the endogenous production of testosterone, dihydrotestosterone, androstenedione and other steroids in this species. Furthermore, the sex-specific production of vertebrate-type steroids was quantified (Verslycke et al., Gen. Comp. Endocrinol., accepted). The use of liquid chromatography coupled with multiple mass spectrometry allows a unique quantification of both endogenously produced and in vivo produced metabolites in single mysid. Quantitative changes in the biotransformation profile of testosterone were evaluated after exposure to endocrine disruptors (e.g. tributyltin). The results of these experiments provided us with new insights in the use of metabolic studies as predictive biomarkers for endocrine disruption, but also led to new questions regarding a possible function of vertebrate-type steroids in mysids. Key words: testosterone metabolism, Neomysis integer, endocrine disruption, invertebrate |
