title: Degradation, residual determination, and cholinesterase activity of triclorfon in Piaractus mesopotamicus Holmberg (PACU) 1887.
abstract: The aim of this study was to determine the no-observable-adverse-effect concentration (NOAEC) for trichlorfon, an antiparasitic agent used in aquaculture, in Piractus mesopotamicus (pacu) using acetylcholinesterase (AChE) activity as an end point. Fish were exposed 24 h/d for 15 d to different concentrations of trichlorfon in tanks of water for which a curve of dissipation was previously determined. Analysis of trichlorfon in water and fish plasma using gas chromatography with electron capture detection (GC-ECD) enabled measurement of limit of detection (LOD) and limit of quantification (LOQ), respectively, to be 3 and 10 ppb. Thirty-six hours after trichlorfon dilution in water, the concentration was below the LOD, and data showed that plasma concentrations did not exceed the LOQ. Apart from the 6.25 μg/L, all concentrations of trichlorfon significantly inhibited plasma and brain AChE activity compared to controls. The AChE activity levels returned to control values in 7 d. These data may be useful to determine the concentration of trichlorfon that destroys parasites without producing adverse effects in fish.
authors.affiliation: a Faculdade de Ciências Agrárias e Veterinárias, UNESP, Univ Estadual Paulista Campus de Jaboticabal , Departamento de Morfologia e Fisiologia Animal, Laboratório de Famacologia e Fisiologia do Exercício Equino , Jaboticabal , São Paulo , Brazil.
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Mataqueiro
authors.forename: Laura Satiko Okada
authors.initials: LS
authors.lastname: Nakaghi
authors.forename: Patrícia Kii
authors.initials: PK
authors.lastname: Yamada
authors.forename: Guilherme
authors.initials: G
authors.lastname: de Camargo Ferraz
authors.forename: Antonio
authors.initials: A
authors.lastname: de Queiroz-Neto
authors.forename: Georgino Honorato
authors.initials: GH
authors.lastname: DeOliveira
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D000871:Anthelmintics / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity*; D017756:Aquaculture; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000201:enzymology; D060126:Characidae / Q000378:metabolism*; D002849:Chromatography, Gas; D004305:Dose-Response Relationship, Drug; D057230:Limit of Detection; D016014:Linear Models; D019055:No-Observed-Adverse-Effect Level; D014236:Trichlorfon / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity*; D014867:Water / Q000737:chemistry
chemical_list: D000871:Anthelmintics; D015415:Biomarkers; D014867:Water; D014236:Trichlorfon; D000110:Acetylcholinesterase