Use of atropine-treated Daphnia magna survival for detection of environmental contamination by acetylcholinesterase inhibitors.
The toxicity of cholinesterase-inhibiting compounds (e.g., carbamates and organophosphates) is due to a decrease in acetylcholine metabolism, which results in a continuous stimulation of cholinergic receptors (muscarinic and nicotinic) that can be fatal. The goal of this study was to evaluate the protective effect of atropine (muscarinic receptor antagonist) against paraoxon-induced toxicity to Daphnia magna using its survival rate for the detection of environmental contamination by cholinesterase-inhibiting compounds. As expected, paraoxon was lethal to D. magna in a concentration-dependent manner. Noteworthy, the pretreatment of these organisms with atropine dramatically increased their survival against paraoxon. These results indicate that muscarinic stimulation plays an important role in paraoxon-induced lethality in D. magna. Therefore, simply by using the survival of atropine-treated and nontreated D. magna, water contamination by cholinesterase-inhibiting compounds may be rapidly and specifically detected.
Carvalho
Félix Dias
FD
ICETA/CEQUP, Toxicology Department, Faculty of Pharmacy, University of Porto, Rua Aníbal Cunha, 164, 4050-047 Porto, Portugal. felixdc@ff.up.pt
Machado
Inês
I
Martínez
M Sánchez
MS
Soares
Amadeu
A
Guilhermino
Lúcia
L
D000818:Animals; D001285:Atropine / Q000494:pharmacology*; D015415:Biomarkers / Q000032:analysis; D002800:Cholinesterase Inhibitors / Q000009:adverse effects*; D003621:Daphnia; D018727:Muscarinic Antagonists / Q000494:pharmacology*; D010261:Paraoxon / Q000009:adverse effects*; D013534:Survival; D014874:Water Pollutants, Chemical / Q000009:adverse effects*
D015415:Biomarkers; D002800:Cholinesterase Inhibitors; D018727:Muscarinic Antagonists; D014874:Water Pollutants, Chemical; D001285:Atropine; D010261:Paraoxon