http://www.vliz.be/imisdocs/publications/56382.pdf

Role of B-esterases in assessing toxicity of organophosphorus (chlorpyrifos, malathion) and carbamate (carbofuran) pesticides to Daphnia magna.

The main objective of the present study was to investigate if a battery of enzymatic biomarkers was suitable for use as effect criteria in acute toxicity tests with Poecilia reticulata. To attain this objective, the in vivo effects of dimethoate and beta-naphthoflavone on acetylcholinesterase (AChE), cytochrome P4501A-dependent monooxygenase activity of 7-ethoxyresorufin O-deethylase (EROD), glutathione S-transferases (GST), lactate dehydrogenase (LDH) and Na+-K+-ATPase activities of P. reticulata were studied. After 96 h of exposure to sublethal concentrations (0.063 mg l−1 to 1 mg l−1) of the pesticide, an inhibition of the enzymes AChE and GST, as well as an induction of LDH was observed. The compound beta-naphthoflavone significantly induced both EROD and GST. The remaining enzymes analysed were not significantly altered by the exposure to beta-naphthoflavone (0.82 mg l−1 to 1.7 mg l−1). These results suggest that in vivo toxicity tests based on the biomarkers used in this study are sensitive and present advantages to conventional acute tests based on mortality, since they were able to detect sublethal effects in a short-period of time (96 h) indicating target and/or detoxification mechanisms.

Effects of dimethoate and beta-naphthoflavone on selected biomarkers of Poecilia reticulata

Recently there has been evidence that contaminants other than organophosphate and carbamate pesticides may inhibit the activity of the enzyme acetylcholinesterase (AChE) both under in vitro and in vivo conditions. In this study we investigated the in vitro effect of three detergents \[dodecyl benzyl sulphonate (DBS), sodium dodecyl sulphate (SDS) and a mixture commonly used as domestic detergent (X)] and three metals \[molybdenum, barium and chromium (VI)] on AChE activity of Mytilus galloprovincialis haemolymph. All the detergents tested significantly inhibited the activity of the enzyme. The lowest observed effect concentrations were equal to 12 5 for DBS and 50 mg l-1 for SDS and X. Among the metals, molybdenum and barium had no effect on AChE activity, whereas chromium (VI) significantly depressed the activity of the enzyme at concentrations equal to or higher than 25 mg l-1. These results suggest that the use of AChE as a specific biomarker for organophosphate and carbamate pesticides should be quest...

Should the use of inhibition of cholinesterases as a specific biomarker for organophosphate and carbamate pesticides be questioned

Effects of estuarine sediment contamination on feeding and on key physiological functions of the polychaete Hediste diversicolor: Laboratory and in situ assays.

Amadeu M.V.M. Soared

Papers

Inhibition of acetylcholinesterase activity as effect criterion in acute tests with juvenile Daphnia magna.