In vivo and in vitro exposure of carps to graded concentrations of endocrine disrupting chemicals

This study is a part of a project aiming to screen peptides not yet or not completely related to (anti)-oestrogenic and (anti-androgenic) chemicals to identify and characterise new biomarkers of endocrine disrupting chemicals in aquatic species. Specific aim was to correlate morphological and biochemical alterations in exposed fish to obtain support data for the successive study. K2 carps were exposed for 2 weeks to graded concentrations of ethynil-oestradiol, Tamoxifen, methyldihydrotestosterone and Flutamide. Fish were sampled at starting exposure (T0) and ending time (T15). Gonads and liver were fixed for histological and histochemical analyses, or immediately deep frozen for biomolecular studies. Plasma aliquots were stored at –80°C for biomarker and sex steroid measurements. In parallel, isolated follicular cells (FC) and testis fragments were simply incubated at room temperature or exposed to scalar dilutions of the above four chemicals in presence or absence of carp pituitary homogenate and 25-hydroxycholesterol. Media were analysed for sex steroids. Morphological alteration in gonads and liver are described and related to biomarker expression and endogenous steroidogenesis.