title: Cerium oxide nanoparticles exhibit minimal cardiac and cytotoxicity in the freshwater fish Catostomus commersonii.
abstract: Metal oxide nanomaterials can cause oxidative, cardiorespiratory, and osmoregulatory stress in freshwater fish. In contrast, cerium oxide nanoparticles (nCeO2) can have antioxidant effects but their aquatic toxicity has not been fully characterized. Heart rate and heart rate variability were followed in white sucker (Catostomus commersonii) acutely exposed to 1.0 mg L(-1) nCeO2 for 25 h. Malondialdehyde (MDA) was measured to assess oxidative tissue damage, and plasma cortisol, glucose, lactate, and osmolality were assessed as indicators of physiological and osmoregulatory stress. There was no MDA accumulation in gill or heart of fish exposed to nCeO2 and heart function was unchanged over the 25 h treatment. Plasma cortisol increased 6-fold but there was no change in plasma glucose or lactate. Cellular osmoregulatory toxicity was studied using an isolated red blood cell (RBC) model. In vitro exposure to 1.0 mg L(-1) nCeO2 for 1h had no effect on cell morphological parameters and did not sensitize RBCs to hemolysis under hypotonic stress. Overall, there were no indications of oxidative, cardiorespiratory, or osmoregulatory stress following acute exposure to nCeO2. Elevated plasma cortisol levels suggest that nCeO2 may exert mild toxicity to tissues outside of the cardiorespiratory system.
authors.affiliation: Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada.
authors.forename: Amanda
authors.initials: A
authors.lastname: Rundle
authors.affiliation: Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada.
authors.forename: Anne B
authors.initials: AB
authors.lastname: Robertson
authors.affiliation: Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada.
authors.forename: Alexandra M
authors.initials: AM
authors.lastname: Blay
authors.affiliation: Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada.
authors.forename: Kathryn M A
authors.initials: KM
authors.lastname: Butler
authors.affiliation: Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada.
authors.forename: Neal I
authors.initials: NI
authors.lastname: Callaghan
authors.affiliation: Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Dieni
authors.affiliation: Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB E4L 1G8, Canada. Electronic address: tmaccormack@mta.ca.
authors.forename: Tyson J
authors.initials: TJ
authors.lastname: MacCormack
mesh_terms: D000818:Animals; D002563:Cerium / Q000633:toxicity*; D003531:Cypriniformes / Q000502:physiology*; D004912:Erythrocytes / Q000187:drug effects*; D005618:Fresh Water; D005880:Gills / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006854:Hydrocortisone / Q000097:blood; D008315:Malondialdehyde; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D002563:Cerium; D008315:Malondialdehyde; C030583:ceric oxide; D006854:Hydrocortisone
keywords: Heart rate variability; Nanotoxicology; Osmoregulation; Oxidative stress