title: Oxidative stress responses in relationship to persistent organic pollutant levels in feathers and blood of two predatory bird species from Pakistan.
abstract: To date, knowledge of persistent organic pollutant (POP) mediated oxidative stress responses in avian species is rather limited. We therefore investigated whether exposure to polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs) in two predatory bird species, namely black kite (Milvus migrans) and spotted owlet (Athene brama), was associated to activities of antioxidant enzymes, such as glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GR) and catalase (CAT), or expression of GPx and superoxide dismutase (SOD) genes. As part of this investigation, we evaluated whether feathers were suitable to reflect internal body burdens and their associated oxidative stress effects. p,p'-DDE was unanimously recorded with highest concentrations in feathers and blood of both species. In general, the non-significant associations reflect that feathers are not always a suitable indicator for internal body burdens of POPs, depending on the feather type and the age of the bird. The activity of GST and GR was significantly higher in spotted owlet whereas GPx and CAT was higher (albeit not significant) in spotted owlet and black kite respectively. In comparison, mRNA expression of GPx, SOD and Cu,ZnSOD was significantly higher in black kite. Regression analysis showed that the activity of GST and GR was significantly associated with p,p'-DDE in blood of spotted owlet. Similarly, activity of CAT and GR was significantly correlated with BDE-100 in feathers of spotted owlet. In comparison, mRNA expression of SOD was found significantly associated with ∑PBDEs in blood of spotted owlet as well as p,p'-DDE in feathers of black kite. Significant associations of various POPs with biological responses may suggest that POP exposure may be contributing to oxidative stress in the studied bird of prey species. This first investigation indicates the necessity for further research on cause-effect relationships between POP exposures and changes in general health of free ranging birds.
authors.affiliation: Environmental Biology and Ecotoxicology Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan.
authors.forename: Naeem Akhtar
authors.initials: NA
authors.lastname: Abbasi
authors.affiliation: Environmental Toxicology, Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: Augustine
authors.initials: A
authors.lastname: Arukwe
authors.affiliation: Environmental Toxicology, Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway. Electronic address: veerle.jaspers@ntnu.no.
authors.forename: Veerle L B
authors.initials: VLB
authors.lastname: Jaspers
authors.affiliation: Department of Bioscience, Aarhus University, Frederiksborgvej 399, P.O. Box 358, 4000 Roskilde, Denmark.
authors.forename: Igor
authors.initials: I
authors.lastname: Eulaers
authors.affiliation: Department of Veterinary Sciences, University of Pisa, Italy.
authors.forename: Elvira
authors.initials: E
authors.lastname: Mennilo
authors.affiliation: Department of Zoology and Environmental Biology, University of Calabar, Nigeria.
authors.forename: Oju Richard
authors.initials: OR
authors.lastname: Ibor
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, UPEC, Paris 7, CNRS, INRA, IRD, Institut d'Ecologie et des Sciences de l'Environnement de Paris, F-75005 Paris, France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Frantz
authors.affiliation: Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
authors.forename: Adrian
authors.initials: A
authors.lastname: Covaci
authors.affiliation: Environmental Biology and Ecotoxicology Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan. Electronic address: r_n_malik2000@yahoo.co.uk.
authors.forename: Riffat Naseem
authors.initials: RN
authors.lastname: Malik
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D004785:Environmental Pollutants / Q000009:adverse effects*; D046093:Falconiformes / Q000097:blood*; D005241:Feathers / Q000737:chemistry*; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D055768:Halogenated Diphenyl Ethers / Q000009:adverse effects*; D018384:Oxidative Stress; D010154:Pakistan; D020305:Strigiformes / Q000097:blood*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D004785:Environmental Pollutants; D055768:Halogenated Diphenyl Ethers; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005982:Glutathione Transferase
keywords: Black kite; Enzyme activity; Gene expression; Non-destructive; Spotted owlet