Effect of diet on carboxylesterase activity of tadpoles (Rhinella arenarum) exposed to chlorpyrifos

• Published in: Ecotoxicology and environmental safety 2017-01, Vol.135, p.10-16
• Main Authors: Attademo, A.M., Sanchez-Hernandez, J.C., Lajmanovich, R.C., Peltzer, P.M., Junges, C.
• Format: Article
• Language: English
• Subjects: Acetylcholinesterase; Acetylcholinesterase - metabolism; Amphibians; Animals; Argentina; Bufo arenarum; Carboxylesterase; Carboxylesterase - metabolism; Chlorpyrifos - toxicity; Diet; Environmental Monitoring; Environmental Pollutants - toxicity; Intestines - drug effects; Intestines - enzymology; Lactuca sativa; Larva - drug effects; Larva - enzymology; Nitrobenzenes; Organophosphorus; Outdoor microcosm; Pesticide detoxification; Pesticides - toxicity; Valerates
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2016.09.012

An outdoor microcosm was performed with tadpoles (Rhinella arenarum) exposed to 125μgL−1 chlorpyrifos and fed two types of food, i.e., lettuce (Lactuca sativa) and a formulated commercial pellet. Acetylcholinesterase (AChE) and carboxylesterase (CbE) activities were measured in liver and intestine after 10 days of pesticide exposure. Non-exposed tadpoles fed lettuce had an intestinal AChE activity almost two-fold higher than that of pellet-fed tadpoles. No significant differences were observed, however, in liver AChE activity between diets. Likewise, intestinal CbE activity – measured using two substrates, i.e. 1-naphthyl acetate (1-NA) and 4-nitrophenyl valerate (4-NPV) – was higher in tadpoles fed lettuce than in those fed pellets. However, the diet-dependent response of liver CbE activity was opposite to that in the intestine. Chlorpyrifos caused a significant inhibition of both esterase activities, which was tissue- and diet-specific. The highest inhibition degree was found in the intestinal AChE and CbE activities of lettuce-fed tadpoles (42–78% of controls) compared with pellet-fed tadpoles (