|
(057) The testosterone metabolism of Neomysis integer : how different are we from shrimp? Verslycke, Tim1, De Wasch, Katia2, Janssen, Colin1, De Brabander, Hubert2, 1 2 ABSTRACT- Both vertebrate and invertebrate species use enzymatic biotransformations for 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 under hormone control, disruption of the hormone function can lead to potential effects on enzyme function and subsequently steroid homeostasis. The testosterone metabolism has therefore been proposed as a biomarker of exposure to endocrine disruptive compounds (Baldwin and Leblanc, Environ. Toxicol. Chem., 13(7), 1013-1021, 1994). In the present study, the estuarine crustacean Neomysis integer (Crustacea, Mysidacea) was exposed to both testosterone and [14C]-testosterone. Identification and quantification of testosterone metabolites and endogenous steroids was done using TLC and LC-MSn. N. integer metabolises testosterone extensively: 8 mono-hydroxy metabolites, androstenedione, boldenone (an anabolic steroid which to our knowledge has not yet been recorded in invertebrates), dihydrotestosterone,... were identified and quantified. Strong evidence of a sex-specific metabolisation of testosterone was observed in N. integer. Endogenous vertebrate-type steroids were also identified and quantified in unexposed N. integer. Testosterone was produced by both female and male N. integer and was quantified for the first time in mysid shrimp. These new insights show an enzymatic biotransformation ability and steroid metabolism in mysid shrimp that rivals that of vertebrate species. Future research on the steroid metabolism of N. integer could result in the development of predictive biomarkers for detection of endocrine disruption in estuarine environments. These results stimulate further research on the use of invertebrates as relevant test species for the effects of endocrine disruptors. Key words: testosterone metabolism, Neomysis integer , endocrine disruption, invertebrate |
