title: Cadmium-induced olfactory dysfunction in rainbow trout: Effects of binary and quaternary metal mixtures.
abstract: A functioning olfactory response is essential for fish to be able to undertake essential behaviors. The majority of work investigating the effects of metals on the olfactory response of fish has focused on single-metal exposures. In this study we exposed rainbow trout to cadmium, copper, nickel, zinc, or a mixture of these four metals at or below the current Canadian Council of Ministers of the Environment guidelines for the protection of aquatic life. Measurement of olfactory acuity using an electro-olfactogram demonstrated that cadmium causes significant impairment of the entire olfactory system, while the other three metals or the mixture of all four metals did not. Binary mixtures with cadmium and each of the other metals demonstrated that nickel and zinc, but not copper, protect against cadmium-induced olfactory dysfunction. Testing was done to determine if the protection from cadmium-induced olfactory dysfunction could be explained by binding competition between cadmium and the other metals at the cell surface, or if the protection could be explained by an up-regulation of an intracellular detoxification pathway, namely metallothionein. This study is the first to measure the effects of binary and quaternary metal mixtures on the olfactory response of fish, something that will aid in future assessments of the effects of metals on the environment.
authors.affiliation: Biological Sciences, University of Lethbridge, Lethbridge, Alberta T1 K 3M4, Canada; Department of Biology, Trent University, Peterborough, Ontario K9 J 7B8, Canada.
authors.forename: William A
authors.initials: WA
authors.lastname: Dew
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8 P 5C2 Canada.
authors.forename: Nik
authors.initials: N
authors.lastname: Veldhoen
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8 P 5C2 Canada.
authors.forename: Amanda C
authors.initials: AC
authors.lastname: Carew
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8 P 5C2 Canada.
authors.forename: Caren C
authors.initials: CC
authors.lastname: Helbing
authors.affiliation: Biological Sciences, University of Lethbridge, Lethbridge, Alberta T1 K 3M4, Canada. Electronic address: gregory.pyle@uleth.ca.
authors.forename: Greg G
authors.initials: GG
authors.lastname: Pyle
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002104:Cadmium / Q000633:toxicity*; D002170:Canada; D004781:Environmental Exposure; D008658:Inactivation, Metabolic / Q000235:genetics; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism; D008670:Metals / Q000633:toxicity*; D017686:Oncorhynchus mykiss / Q000502:physiology*; D012903:Smell / Q000187:drug effects*; D015854:Up-Regulation / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D002104:Cadmium; D008668:Metallothionein
keywords: Cadmium; Electro-olfactogram; Metal; Metallothionein; Mixture; qPCR