title: The beta-receptor blocker metoprolol alters detoxification processes in the non-target organism Dreissena polymorpha.
abstract: Due to increasing amounts of pharmaceutically active compounds (PhACs) in the aquatic environment, their largely unknown effects to non-target organisms need to be assessed. This study examined physiological changes in the freshwater mussel Dreissena polymorpha exposed to increasing concentrations (0.534, 5.34, 53.4 and 534 microg L(-1)) of the beta-blocker metoprolol in a flow-through system for seven days. The two lower concentrations represent the environmentally relevant range. Surprisingly, metallothionein mRNA was immediately up-regulated in all treatments. For the two higher concentrations mRNA up-regulation in gills was found for P-glycoprotein after one day, and after four days for pi class glutathione S-transferase, demonstrating elimination and biotransformation processes, respectively. Additionally, catalase and superoxide dismutase were up-regulated in the digestive gland indicating oxidative stress. In all treated mussels a significant up-regulation of heat shock protein mRNA was observed in gills after four days, which suggests protein damage and the requirement for repair processes. Metoprolol was 20-fold bioaccumulated for environmentally relevant concentrations.
authors.affiliation: Dpt. Ecophysiology and Aquaculture, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 301, 12587 Berlin, Germany. contardo@igb-berlin.de
authors.forename: Valeska
authors.initials: V
authors.lastname: Contardo-Jara
authors.forename: Stephan
authors.initials: S
authors.lastname: Pflugmacher
authors.forename: Gunnar
authors.initials: G
authors.lastname: Nützmann
authors.forename: Werner
authors.initials: W
authors.lastname: Kloas
authors.forename: Claudia
authors.initials: C
authors.lastname: Wiegand
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000493:pharmacokinetics / Q000633:toxicity*; D000818:Animals; D004064:Digestive System / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D049875:Dreissena / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D054750:Ecotoxicology; D015870:Gene Expression / Q000187:drug effects; D005880:Gills / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D008668:Metallothionein / Q000235:genetics; D008790:Metoprolol / Q000493:pharmacokinetics / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics; D018336:Receptors, Aryl Hydrocarbon / Q000235:genetics; D015854:Up-Regulation; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics / Q000633:toxicity*
chemical_list: D000319:Adrenergic beta-Antagonists; D018840:HSP70 Heat-Shock Proteins; D018336:Receptors, Aryl Hydrocarbon; D014874:Water Pollutants, Chemical; D008668:Metallothionein; D008790:Metoprolol