<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Chlorpyrifos (CPF) is a broad spectrum pesticide commonly used for insect control, has great affinity for lipids and is thus a potential for bioaccumulation in aquatic organisms. The aim of this study was to evaluate the toxicity of CPF using the common toad <italic>Rhinella arenarum</italic> via dermal uptake in plastic bucket to simulate their natural exposition in ponds. <italic>R. arenarum</italic> toads were exposed individually to solutions containing a nominal concentration of a commercial formulation of CPF insecticide (5 and 10 mg/L). Different enzyme biomarkers (BChE: butyrylcholinesterase, CbE: carboxylesterase, and CAT: catalase) were measured in blood tissue after exposition. The capacity of pyridine-2-aldoxime methochloride (2-PAM) to reverse OP-inhibited plasma BChE and the ratio of heterophils and lymphocytes (H/L) as hematological indicators of stress were also determined. The normal values of plasma B-sterases (BChE and CbE) were highly inhibited (until ≈ 70%) in toads 48 h after exposure to CPF. The results indicate that 2-PAM produced BChE reactivation as well. The activity of CAT was also inducted for dermal exposure at more than double of that in the control toads (CPF; 5 mg/L). H/L ratios did not reveal a significantly increased stress. The study suggests that CPF via dermal uptake induced neurotoxicity and oxidative stress in the common toad <italic>R. areanum</italic>. Thus, some blood biomarkers employed in our study (i.e. BChE, CbE, 2-PAM, and CAT) might be used as predictors in health and ecological risk assessment of amphibian populations exposed to CPF.</p></abstract>

Chlorpyrifos (CPF) is a broad spectrum pesticide commonly used for insect control, has great affinity for lipids and is thus a potential for bioaccumulation in aquatic organisms. The aim of this study was to evaluate the toxicity of CPF using the common toad Rhinella arenarum via dermal uptake in plastic bucket to simulate their natural exposition in ponds. R. arenarum toads were exposed individually to solutions containing a nominal concentration of a commercial formulation of CPF insecticide (5 and 10 mg/L). Different enzyme biomarkers (BChE: butyrylcholinesterase, CbE: carboxylesterase, and CAT: catalase) were measured in blood tissue after exposition. The capacity of pyridine-2-aldoxime methochloride (2-PAM) to reverse OP-inhibited plasma BChE and the ratio of heterophils and lymphocytes (H/L) as hematological indicators of stress were also determined. The normal values of plasma B-sterases (BChE and CbE) were highly inhibited (until ≈ 70%) in toads 48 h after exposure to CPF. The results indicate that 2-PAM produced BChE reactivation as well. The activity of CAT was also inducted for dermal exposure at more than double of that in the control toads (CPF; 5 mg/L). H/L ratios did not reveal a significantly increased stress. The study suggests that CPF via dermal uptake induced neurotoxicity and oxidative stress in the common toad R. areanum. Thus, some blood biomarkers employed in our study (i.e. BChE, CbE, 2-PAM, and CAT) might be used as predictors in health and ecological risk assessment of amphibian populations exposed to CPF.

Blood biomarkers of common toad <italic>Rhinella arenarum</italic> following chlorpyrifos dermal exposure

Facultad de Bioquímica y Ciencias Biológicas

Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)

Interdisciplinary Toxicology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Blood biomarkers of common toad  following chlorpyrifos dermal exposure

Chlorpyrifos (CPF) is a broad spectrum pesticide commonly used for insect control, has great affinity for lipids and is thus a potential for bioaccumulation in...

Blood biomarkers of common toad Rhinella arenarum following chlorpyrifos dermal exposure

Published Online: Mar 02, 2019

Page range: 148 - 154

Received: Jan 14, 2018

Accepted: Feb 17, 2018

DOI: https://doi.org/10.2478/intox-2018-0011

Keywords
blood, chlorpyrifos dermal exposure, B-esterases, catalase

© 2018 Interdisciplinary Toxicology, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Blood biomarkers of common toad Rhinella arenarum following chlorpyrifos dermal exposure

Published Online: Mar 02, 2019

Page range: 148 - 154

Received: Jan 14, 2018

Accepted: Feb 17, 2018

DOI: https://doi.org/10.2478/intox-2018-0011

Keywordsblood, chlorpyrifos dermal exposure, B-esterases, catalase

© 2018 Interdisciplinary Toxicology, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
blood, chlorpyrifos dermal exposure, B-esterases, catalase