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(T/MF208) Multigeneration study with an aromatase inhibitor: the effects on reproduction and sex differentiation of medaka. Ruymen, Vanessa1, Ollevier, Frans1, 1 ABSTRACT- There is a growing concern on possible, harmful consequences of exposure to xenobiotic compounds that are modulating the endocrine system. Most studies have however overwhelming focussed on the detection and effects of environmental estrogens. There are other chemicals, like aromatase inhibitors, which are non estrogenic but can potentially disrupt the endocrine system. The aromatase enzyme mediates the conversion of androgens to estrogens. Recent field and laboratory studies indicate that the suppression of aromatase enzyme activity can lead to increased testosterone levels and masculinisation of female organisms. Sexual mature medakas (F0) were exposed in a flow-through system for 28 days to 0.5, 5, 50 or 500 ppb fadrozole. F1 eggs and fry were thereafter exposed in the parental concentrations and reared till sexual maturity and reproduction. Studied endpoints were egg production, fertilisation rate, hatching rate, survival, sex differentiation and plasma 11-KT and VTG levels. Results of 2 generations exposure will be discussed. Key words: aromatase inhibition, medaka, multigeneration, reproduction |
