title: Effects of in vivo chronic exposure to pendimethalin on EROD activity and antioxidant defenses in rainbow trout (Oncorhynchus mykiss).
abstract: Pendimethalin, an herbicide active substance frequently used in terrestrial systems, has detected in European aquatic ecosystems. Reliable indicators still need to be found in order to properly assess the impact of pesticides in fish. After an in vivo chronic exposure to pendimethalin, the detoxification process and the antioxidant defense system were assessed in 120 adult rainbow trout, Oncorhynchus mykiss. Four nominal exposure conditions were tested: control (C), 500 ng L(-1) (P500), 800 ng L(-1) (P800) and the commercial formulation Prowl(®) at 500 ng L(-1) (Pw500). Fish samples were made after a 28 day exposure period (D28) and after a fifteen day recovery period in clean fresh water (D43). At D28, ethoxyresorufin-O-deethylase (EROD) activity was not activated in liver in spite of the pendimethalin uptake in fish. At D43, EROD activity in fish exposed to the commercial product was lower than in control fish, which may be explained by the high presence of herbicide in fish (613±163 ng g bile(-1)). Furthermore, antioxidant defense responses were set up by trout in gills and liver following chronic exposure to 800 ng L(-1) of pendimethalin concentration. While the glutathione content (GSH) decreased in gills, it increased in liver associated with higher activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD). These disturbances could lead to reactive oxygen species production and oxidative stress in the vital organs in fish. After fifteen days in clean water, while the SOD activity was restored, the GSH content and GPx activity were still significantly disturbed in fish exposed to pendimethalin in comparison with control. These significant differences between treatments in antioxidant defenses parameters measured, attesting to the irreversibility of the effects.
authors.affiliation: ANSES, Ploufragan-Plouzané Laboratory, Unit of Viral Pathology in Fish, Technopôle Brest-Iroise, 29280 Plouzané, France; Université Européenne de Bretagne, France. Electronic address: morgane.danion@anses.fr.
authors.forename: Morgane
authors.initials: M
authors.lastname: Danion
authors.forename: Stéphane
authors.initials: S
authors.lastname: Le Floch
authors.forename: François
authors.initials: F
authors.lastname: Lamour
authors.forename: Claire
authors.initials: C
authors.lastname: Quentel
mesh_terms: D000814:Aniline Compounds / Q000633:toxicity*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D004781:Environmental Exposure; D004789:Enzyme Activation / Q000187:drug effects; D005880:Gills / Q000187:drug effects* / Q000201:enzymology; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D006540:Herbicides / Q000378:metabolism / Q000494:pharmacology; D008099:Liver / Q000187:drug effects*; D017686:Oncorhynchus mykiss / Q000378:metabolism / Q000502:physiology*; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000814:Aniline Compounds; D000975:Antioxidants; D006540:Herbicides; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D005979:Glutathione Peroxidase; D019363:Cytochrome P-450 CYP1A1; D013482:Superoxide Dismutase; D005978:Glutathione; C030856:pendimethalin
keywords: EROD; GPx; GSH; Oncorhynchus mykiss; Pendimethalin; SOD