title: Dietary sodium protects fish against copper-induced olfactory impairment.
abstract: Exposure to low concentrations of copper impairs olfaction in fish. To determine the transcriptional changes in the olfactory epithelium induced by copper exposure, wild yellow perch (Perca flavescens) were exposed to 20 μg/L of copper for 3 and 24h. A novel yellow perch microarray with 1000 candidate genes was used to measure differential gene transcription in the olfactory epithelium. While three hours of exposure to copper changed the transcription of only one gene, the transcriptions of 70 genes were changed after 24h of exposure to copper. Real-time PCR was utilized to determine the effect of exposure duration on two specific genes of interest, two sub-units of Na/K-ATPase. At 24 and 48 h, Na/K-ATPase transcription was down-regulated by copper at olfactory rosettes. As copper-induced impairment of Na/K-ATPase activity in gills can be ameliorated by increased dietary sodium, rainbow trout (Oncorhynchus mykiss) were used to determine if elevated dietary sodium was also protective against copper-induced olfactory impairment. Measurement of the olfactory response of rainbow trout using electro-olfactography demonstrated that sodium was protective of copper-induced olfactory dysfunction. This work demonstrates that the transcriptions of both subunits of Na/K-ATPase in the olfactory epithelium of fish are affected by Cu exposure, and that dietary Na protects against Cu-induced olfactory dysfunction.
authors: Department of Biology, Lakehead University, Thunder Bay, Ontario P7B 5E1, Canada.
authors: Ali
authors: A
authors: Azizishirazi
authors: Department of Biology, Brandon University, Brandon, Manitoba R7A 6A9, Canada; Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada.
authors: William A
authors: WA
authors: Dew
authors: Institut National de la Recherche Scientifique, Centre INRS Eau Terre et Environnement, 490, rue de la Couronne, Québec City, Québec G1K 9A9, Canada.
authors: Berenice
authors: B
authors: Bougas
authors: Département de biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec City, Québec G1V 0A6, Canada.
authors: Louis
authors: L
authors: Bernatchez
authors: Department of Biology, Lakehead University, Thunder Bay, Ontario P7B 5E1, Canada; Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada. Electronic address: gregory.pyle@uleth.ca.
authors: Greg G
authors: GG
authors: Pyle
mesh_terms: D000818:Animals; D003300:Copper / Q000633:toxicity*; D005786:Gene Expression Regulation / Q000187:drug effects; D005880:Gills / Q000187:drug effects*; D017686:Oncorhynchus mykiss / Q000235:genetics / Q000502:physiology; D010471:Perches / Q000235:genetics / Q000502:physiology; D020011:Protective Agents / Q000494:pharmacology; D012903:Smell / Q000187:drug effects; D012982:Sodium, Dietary / Q000494:pharmacology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D020011:Protective Agents; D012982:Sodium, Dietary; D014874:Water Pollutants, Chemical; D003300:Copper; D000254:Sodium-Potassium-Exchanging ATPase
keywords: Copper; Electro-olfactogrphy; Microarray; Olfaction; Olfactory toxicity; Real-time PCR