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(80-85) Multi Xenobiotic Resistance related transport in two mussel species at different temperatures and contamination situations. Köhler, Angela*,1, Einsporn, Sonja1, 1 Alfred Wegener Institute for Polar and Marine Research, Department of Ecotoxicology and Ecophysiology, Am Handelshafen 12, 27570 Bremerhaven, Germany ABSTRACT- MXR transport activity related to the transmembrane P-glycoprotein was measured in living gills of mussel with a specific fluorogenic substrate Calcein-AM (Molecular Probes) and quantified by computerised image analysis. Mytilus edulis were sampled at Fjord sites of the North Atlantic (Norway) and the North Sea (Island of Sylt). Mytilus galloprovincialis were obtained from a Mediterranean aquaculture company (La Spezia, Italy). In order to interpret the data obtained from Mytilus species inhabiting different climate zones we tested whether various temperature conditions influence the transport activity of the P-gp drug efflux pump. For this purpose, the 2 mussel species were pre-adapted to 0oC, 5oC, 15oC and 25oC water temperature for 12h. Mytilus edulis from a reference site in the Northern hemisphere transported best at lower water temperatures between 0oC and 5oC while Mytilus galloprovincialis from the southern hemisphere showed no significant temperature preference. Yet, transport efficiency in Mytilus galloprovincialis was significantly better than that of Mytilus edulis from the NA and the North Sea. In the frame of the development of novel biomarkers in BEEP it was a further relevant aim to test the MXR activity assay for rapid application in individuals collected from differently polluted sites. MXR activity in gills of Mytilus edulis sampled in Norwegian fjords showed significant inhibition of drug transport at the site of high PAH, Aluminium and Iron input (sum PAHs 31320 ug/kg w w; Aluminium 585mg/kg ww; Iron 3546 mg/kg ww) while at a site of high copper input alone no effects on xenobiotic efflux was noted. We conclude that further information on inhibitory and inducing effects of single compounds in addition to the effects of abiotic factors such as temperature and salinity are needed to identify the role of this very important defence mechanism in invertebrates and its applicability as biomarker of pollutant effects. Key words: MXR transport assay, temperature and contamination, Mytilus edulis and M. galloprovincialis, biomarker |
