title: Toxicity of the insecticide chlorpyrifos to the South American toad Rhinella arenarum at larval developmental stage.
abstract: Chlorpyrifos (CPF) is an insecticide widely used for pest control in the fruit-productive region of North Patagonia, Argentina, where it is found in superficial waters. The aim of this study was to establish the toxic effects of CPF in Rhinella arenarum toad larvae as a potentially exposed species. We determined the 96 h-LC50 (1.46 ± 0.27 mg/L), the LOEC (0.81 mg/L, LC10) and NOEC (0.43 mg/L, LC1) for CPF lethality as endpoint. We also analyzed biochemical biomarkers in larvae exposed to sublethal CPF concentrations. The IC50 for cholinesterase was 0.113 ± 0.026 mg/L, one order of magnitude lower than the LC50. Carboxylesterase activity was inhibited, buffering OP toxicity on cholinesterase. Reduced glutathione increased after 24h as an antioxidant response, and decreased at 96 h together with catalase activity, due to oxidative stress. These biochemical effects suggest that environmentally relevant CPF concentrations pose a threat to R. arenarum larvae progression.
authors: Laboratorio de Investigaciones Bioquímicas y Químicas del Ambiente (LIBIQUIMA), Facultad de Ingeniería, Universidad Nacional del Comahue - CONICET, Buenos Aires 1400, 8300 Neuquén, Argentina(2); Facultad de Ciencias Agrarias, Universidad Nacional del Comahue, Ruta 151 Km 12.5, 8303 Cinco Saltos, Río Negro, Argentina(3).
authors: Natacha
authors: N
authors: Liendro
authors: Laboratorio de Investigaciones Bioquímicas y Químicas del Ambiente (LIBIQUIMA), Facultad de Ingeniería, Universidad Nacional del Comahue - CONICET, Buenos Aires 1400, 8300 Neuquén, Argentina(2); Facultad de Ciencias Médicas, Universidad Nacional del Comahue, Toschi y Arrayanes, 8324 Cipolletti, Río Negro, Argentina.
authors: Ana
authors: A
authors: Ferrari
authors: Laboratorio de Investigaciones Bioquímicas y Químicas del Ambiente (LIBIQUIMA), Facultad de Ingeniería, Universidad Nacional del Comahue - CONICET, Buenos Aires 1400, 8300 Neuquén, Argentina(2); Facultad de Ciencias Agrarias, Universidad Nacional del Comahue, Ruta 151 Km 12.5, 8303 Cinco Saltos, Río Negro, Argentina(3).
authors: Mariana
authors: M
authors: Mardirosian
authors: Laboratorio de Investigaciones Bioquímicas y Químicas del Ambiente (LIBIQUIMA), Facultad de Ingeniería, Universidad Nacional del Comahue - CONICET, Buenos Aires 1400, 8300 Neuquén, Argentina(2); Facultad de Ciencias Agrarias, Universidad Nacional del Comahue, Ruta 151 Km 12.5, 8303 Cinco Saltos, Río Negro, Argentina(3).
authors: Cecilia I
authors: CI
authors: Lascano
authors: Laboratorio de Investigaciones Bioquímicas y Químicas del Ambiente (LIBIQUIMA), Facultad de Ingeniería, Universidad Nacional del Comahue - CONICET, Buenos Aires 1400, 8300 Neuquén, Argentina(2); Facultad de Ciencias Agrarias, Universidad Nacional del Comahue, Ruta 151 Km 12.5, 8303 Cinco Saltos, Río Negro, Argentina(3). Electronic address: a.venturino@conicet.gov.ar.
authors: Andrés
authors: A
authors: Venturino
mesh_terms: D029845:Amphibian Proteins / Q000378:metabolism; D000818:Animals; D002025:Bufonidae / Q000254:growth & development / Q000378:metabolism; D043182:Carboxylesterase / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D004390:Chlorpyrifos / Q000633:toxicity*; D002802:Cholinesterases / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007306:Insecticides / Q000633:toxicity*; D007814:Larva / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D007928:Lethal Dose 50; D019055:No-Observed-Adverse-Effect Level
chemical_list: D029845:Amphibian Proteins; D007306:Insecticides; D002374:Catalase; D005982:Glutathione Transferase; D043182:Carboxylesterase; D002802:Cholinesterases; D005978:Glutathione; D004390:Chlorpyrifos
keywords: Amphibians; Biomarkers; Cholinesterase inhibition; Organophosphates; Oxidative stress