Subchronic exposure to chlorpyrifos affects energy expenditure and detoxification capacity in juvenile Japanese quails

• Published in: Chemosphere (Oxford) 2016-02, Vol.144, p.775-784
• Main Authors: Narváez, Cristóbal, Ríos, Juan Manuel, Píriz, Gabriela, Sanchez-Hernandez, Juan C., Sabat, Pablo
• Format: Article
• Language: English
• Subjects: Aerobic performance; Animals; Butyrylcholinesterase - metabolism; Carboxylesterase - metabolism; Chlorpyrifos; Chlorpyrifos - toxicity; Cholinesterases - metabolism; Coturnix - metabolism; Coturnix coturnix japonica; Coturnix japonica; Detoxification; Ecotoxicology; Energy Metabolism - drug effects; Environmental Pollutants - toxicity; Enzymes; Esterases; Expenditures; Exposure; Inhibition; Organophosphorus pesticides; Pesticides; Physiological responses; Sampling; Time Factors
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2015.09.060

Effects of pesticides on non-target organisms have been studied in several taxa at different levels of biological organization, from enzymatic to behavioral responses. Although the physiological responses may be associated with higher energy costs, little is known about metabolic costs of pesticide detoxification in birds. To fill this gap, we exposed orally (diet) 15-d old Coturnix coturnix japonica individuals to sublethal doses of chlorpyrifos (10 and 20 mg active ingredient/kg dry food) for four weeks. Carboxylesterase (CbE), butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) activities were periodically measured in multiple tissues along with measurements of resting (RMR) and maximum metabolic rates (Msum). Furthermore, glucuronic acid in bird excreta was also assessed at the end of the trial. While CbE and BChE activities were inhibited by chlorpyrifos in all tissues during the third and fourth weeks following pesticide treatment, AChE activity was unaffected. At this sampling times, both Msum and RMR expansibility decreased. These results suggest that the exposure to chlorpyrifos caused a negative effect on aerobic performance. Additionally, excretion rate of glucuronic acid was up to 2-fold higher in the 20-mg/kg group than in the control and 10-mg/kg chlorpyrifos groups. The inhibition of CbE and BChE activities corroborated that these enzymes are fulfilling their role as bioscavengers for organophosphate pesticides, decreasing its concentration and thus protecting AChE activity against inhibition by chlorpyrifos. •Quails chronically exposed to chlorpyrifos respond through biochemical and systemic modifications.•Esterase activities increases with age in control groups but remains unchanged in exposed birds.•Glucuronic acid output increases in individuals exposed to chlorpyrifos.•Exposure to chlorpyrifos leads to high energy costs in quails, affecting their aerobic performance.