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

CRISTOBAL NARVAEZ; JUAN MANUEL RÍOS; GABRIELA PÍRIZ; JUAN CARLOS SANCHEZ-HERNANDEZ; PABLO SABAT

CHEMOSPHERE

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2016 vol. 144 p. 755 - 784

0045-6535

The effects of pesticide exposure have been studied in several taxa at different levels of biological organization, from the enzymatic to behavioral responses. Although the physiological responses may be associated with higher energy costs, to our knowledge little is known about metabolic costs of pesticide detoxification in birds. To fill this gap, we exposed 15-d old Coturnix coturnix japonica individuals to sublethal doses of chlorpyrifos (10.1 mg/L and 20.2 mg/L) for four weeks. After acclimation, carboxylesterase (CbE), butyrilcholinesterase (BChE) and acetylcholinesterase (AChE) activities were measured in multiple tissues along with measurements of resting (RMR) and maximum metabolic rates (Msum). Further, glucuronic acid in bird excreta at the end of the trial was also assessed. While CbE and BChE activities were inhibited by chlorpyrifos in all tissues during the third and fourth week of pesticide treatments, AChE activity was unaffected. In this same period of sampling, both Msum and metabolic expansibility decreased. These results indicate that the exposure to sublethal doses of chlorpyrifos had a negative effect on aerobic performance. Furthermore, glucuronic acid output was twice in individuals exposed at higher level of chlorpyrifos than in control and lower chlorpyrifos dose. The inhibition of CbE and BChE activities suggested that these enzymes are fulfilling their role of bio scavengers, binding to pesticide to decrease its concentration and thus protecting AChE activity.