| Summary: | Bisphenol A (BPA), a known endocrine disrupting chemical (EDC), was administered by diet to gilthead sea bream (<i>Sparus aurata</i>) in order to study its effects on the endocannabinoid system (ECS) and gonadal steroidogenesis. 2-year-old male gilthead sea bream were fed with two different concentrations of BPA (LOW at 4 and HIGH at 4000 µg/kg body weight for 21 days during the reproductive season. Exposure to 4000 µg BPA/kg bw/day (BPA HIGH) reduced sperm motility and altered the straight-line velocity (VSL) and linearity (LIN). Effects on steroidogenesis were evident, with testosterone (T) being up-regulated by both treatments and 11-ketotestosterone (11-KT) down-regulated by BPA HIGH. Plasma levels of 17β-estradiol (E<sub>2</sub>) were not affected. The Gonadosomatic Index (GSI) increased in the BPA HIGH group. Interestingly, the levels of endocannabinoids and endocannabinoid-like compounds were significantly reduced after both treatments. Unpredictably, a few changes were noticed in the expression of genes coding for ECS enzymes, while the receptors were up-regulated depending on the BPA dose. Reproductive markers in testis (leptin receptor (<i>lepr</i>), estrogen receptors (<i>era</i>, <i>erb</i>), progesterone receptors (<i>pr</i>) and the gonadotropin releasing hormone receptor (<i>gnrhr</i>)) were up-regulated. BPA induced the up-regulation of the hepatic genes involved in oogenesis (vitellogenin (<i>vtg</i>) and zona pellucida 1 (<i>zp1</i>)).
|
|---|
