Characterization of acetylcholinesterase inhibition and energy allocation in Daphnia magna exposed to carbaryl

Jeon, Junho, Kretschmann, Andreas, Escher, Beate I. and Hollender, Juliane (2013) Characterization of acetylcholinesterase inhibition and energy allocation in Daphnia magna exposed to carbaryl. Ecotoxicology and Environmental Safety, 98 28-35. doi:10.1016/j.ecoenv.2013.09.033

Author Jeon, Junho
Kretschmann, Andreas
Escher, Beate I.
Hollender, Juliane
Title Characterization of acetylcholinesterase inhibition and energy allocation in Daphnia magna exposed to carbaryl
Journal name Ecotoxicology and Environmental Safety   Check publisher's open access policy
ISSN 0147-6513
Publication date 2013-12-01
Year available 2013
Sub-type Article (original research)
DOI 10.1016/j.ecoenv.2013.09.033
Open Access Status Not yet assessed
Volume 98
Start page 28
End page 35
Total pages 8
Place of publication Maryland Heights, MO United States
Publisher Academic Press
Language eng
Subject 2307 Health, Toxicology and Mutagenesis
2739 Public Health, Environmental and Occupational Health
2310 Pollution
Abstract The inhibition of acetylcholinesterase (AChE) activity and energy allocation in the freshwater organism Daphnia magna exposed to carbaryl and potential recovery from the effects was examined. The binding of carbaryl-AChE was characterized through in vitro assays. To evaluate the recovery from inhibition and the alteration in energy budget, in vivo exposure and recovery regime tests were conducted. In comparison to diazoxon, the active metabolite of the insecticide diazinon, the stability of enzyme-carbaryl complex was fifteen times lower and the reactivity toward the active site was two times lower, resulting in approximately 30 times lower overall inhibition rate than for diazoxon. The in vitro reactivation rate constant of the inhibited enzyme and the in vivo recovery rate constant of AChE activity were 1.9h-1 and 0.12h-1 for carbaryl, respectively, which are much higher than the corresponding rate constants for diazoxon. The lower AChE inhibition and greater reactivation/recovery rates are in accordance with the lower toxicity of carbaryl compared to diazinon. Carbaryl exposure also altered the profile of the energy reserve: the decrease in lipid and glycogen and the increase in protein content resulted in the reduction of the total energy budget by about 45mJ/gww. This corresponds to 26 percent of the available energy, which might allocate for external stressors. The mechanistic model of AChE inhibition is helpful to get an insight into (eco-)toxicological effects of AChE inhibitors on freshwater crustaceans under environmentally realistic conditions.
Keyword Acetylcholinesterase inhibitor
Daphnia magna
Energy budget
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2014 Collection
National Research Centre for Environmental Toxicology Publications
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