title: Brain cholinesterase reactivation as a marker of exposure to anticholinesterase pesticides: a case study in a population of yellow-legged gull Larus michahellis (Naumann, 1840) along the northern coast of Portugal.
abstract: Between late 2010 to early 2011, an increased mortality in gulls was observed along the northern coast of Portugal, with individuals exhibiting neurologic disorders consistent with an eventual anticholinesterase pesticide poisoning event. To clarify if this mortality was related to organophosphate (OP) and/or carbamate (CB) poisoning, chemical and spontaneous cholinesterase (ChE) reactivation was tested in the brain of the yellow-legged gull (Larus michahellis). Initial brain ChE activity in L. michahellis was 40.92 ± 5.23 U/mg of protein (average ± SE). Following chemical and spontaneous reactivation, ChE activity increased in average 70.38 ± 48.59% and 131.95 ± 92.64%, respectively. ChE reactivation was found to decrease at increasing concentrations of the oxime pyridine-2-aldoxime methochloride and dilution factor, underscoring the importance of first optimizing the assay conditions prior to its use on bird species. These results suggest that birds analysed could have been exposed to OP and CB pesticide compounds and that in most cases CB exposure appeared to be the main cause of birds poisoning. These results are an important contribution to environmental monitoring as it demonstrates the suitability of L. michaellis as sentinel species of OP and CB pesticides within an urban environment.
authors.affiliation: Department of Biology & CESAM, University of Aveiro, 3810-193, Aveiro, Portugal. catiasantos@ua.pt.|Department of Biology, Terrestrial Ecology Unit, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium. catiasantos@ua.pt.
authors.forename: Cátia S A
authors.initials: CS
authors.lastname: Santos
authors.affiliation: Department of Biology & CESAM, University of Aveiro, 3810-193, Aveiro, Portugal.
authors.forename: Marta S
authors.initials: MS
authors.lastname: Monteiro
authors.affiliation: Department of Biology & CESAM, University of Aveiro, 3810-193, Aveiro, Portugal.|Programa de Pós-Graduação em Produção Vegetal, Universidade Federal do Tocantins, Campus de Gurupi. Rua Badejós, Zona Rural, Cx. Postal 66-CEP: 77402-970, Gurupi-TO, Brasil.
authors.forename: Amadeu M V M
authors.initials: AM
authors.lastname: Soares
authors.affiliation: Department of Biology & CESAM, University of Aveiro, 3810-193, Aveiro, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Loureiro
mesh_terms: D000818:Animals; D015415:Biomarkers; D001921:Brain / Q000187:drug effects* / Q000201:enzymology; D002219:Carbamates / Q000633:toxicity; D046091:Charadriiformes / Q000378:metabolism*; D002800:Cholinesterase Inhibitors / Q000633:toxicity*; D002801:Cholinesterase Reactivators / Q000494:pharmacology* / Q000633:toxicity*; D002802:Cholinesterases / Q000378:metabolism; D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D010755:Organophosphates / Q000633:toxicity; D010575:Pesticides / Q000633:toxicity*; D011174:Portugal; D011220:Pralidoxime Compounds
chemical_list: D015415:Biomarkers; D002219:Carbamates; D002800:Cholinesterase Inhibitors; D002801:Cholinesterase Reactivators; D010755:Organophosphates; D010575:Pesticides; D011220:Pralidoxime Compounds; D002802:Cholinesterases; C028797:pralidoxime
keywords: Avian toxicity; Biomarkers; Carbamate pesticides; Chemical reactivation; Organophosphate pesticides; Spontaneous reactivation