Early detection of VEP and VTG in Cichlasoma dimerus (Perciformes, Cichlidae) exposed to octylphenol.

REGUEIRA, M.; LO NOSTRO, F. L.; DA CUÑA, R.; TRUDEAU, V.; PIAZZA, Y. G.; MAGGESE, M. C.; GRISELDA GENOVESE

Montreal

Congreso; North America 27th Annual Meeting. Society of Environmental Toxicology and Chemistry; 2006

SETAC

  There is a growing amount of industrial chemicals that are dumped into the aquatic environment and are capable of acting as endocrine disruptors. In fish exposed to estrogenic compounds, such as octylphenol (OP), feminization is commonly reported, evidenced by the detection of biomarkers such as vitelline envelope proteins (VEP) and vitellogenin (VTG) in males, which are normally expressed only by females. OP is one of several biodegradation byproducts of non-ionic surfactants commonly used in several industries. We analyzed the effects of exposure to an environmentally relevant concentration of OP during 0, 1, 3, 6, 14, 21 and 28 days in mature, male C. dimerus. At each time, surface mucus and blood samples were taken; liver and gonads were collected and processed for histology. Using SDS-PAGE and Western blot techniques, VEP and VTG were detected in plasma of males in increasing levels from day 3 onwards. Mucus samples showed the same pattern, suggesting that the skin could serve as an important accumulation organ for these proteins or as an excretory pathway, considering that they lack a depositional site in males. While no major liver alterations were observed, an abnormal predominance of spermatozoa and scarce intermediate germ cell stages were observed after 28 days of OP exposure. Therefore, a short exposure to estrogenic substances as OP, can be detected very early using VEP and VTG as biomarkers, even in surface mucus, providing a useful non-invasive tool for biomonitoring in this South American freshwater species. Funded by UBACYT X118 & PICT 14271.