Can acetylcholinesterase be considered a biomarker of effect? A study of the mussel Mytilus edulis exposed to the priority pollutant Chlorfenvinphos

University of Saskatchewan, National Water Research Institute, 11 Innovation Blvd, Saskatoon, SK, Canada S7N 3H5.
Aquatic Toxicology (Impact Factor: 3.45). 04/2004; 67(1):45-56. DOI: 10.1016/j.aquatox.2003.11.004
Source: PubMed


The inhibition of acetylcholinesterase (AChE) activity has been used widely as a biomarker of exposure to organophosphorous pesticides (OPs). However, scientific uncertainty about the risk assessment implications of data describing inhibition of cholinesterases in diverse species and tissues has hampered the use of AChE activity as a biomarker of adverse effect. Here, haemolymph AChE activity was combined with biomarkers of cellular integrity, immunotoxicity and physiological status in order to measure exposure to and the effects of the priority pollutant chlorfenvinphos. Laboratory exposures of the blue mussel Mytilus edulis to commercial grade chlorfenvinphos (Sapecron) were conducted over 24, 48 and 96 h. AChE activity in haemolymph of M. edulis was highly variable and bore no relationship to either sublethal effects or lethality over the range 0.003-0.03 mg/l chlorfenvinphos. In comparison, concentration dependent inhibition was evident for each of the remaining biomarkers (phagocytic activity, spontaneous cytotoxicity, neutral red retention time, total haemolymph protein). Mussels at the highest exposure concentration showed visual signs of neurotoxicity (impaired neuromuscular control). Haemocyte phagocytic activity and spontaneous cytotoxicity responses were highly sensitive to chlorfenvinphos with significant modulation evident after 24 h exposure to environmentally realistic concentrations of 0.007 mg/l (P = 0.0003). Thus the immune function and well being of the mussels was significantly impacted in the absence of measurable inhibition of haemolymph AChE.

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Available from: Tamara Susan Galloway, Feb 14, 2014
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    • "In marine mussels, oxyradicals are generated both internally and externally to haemocyte lysosomes (Winston et al., 1996), important sites of pollutant sequestration and detoxification in mussels (Moore, 1985; Viarengo et al., 1987; Domouhtsidou et al., 2004). Lysosomal membrane stability is widely used as a biomarker in environmental biomonitoring (Regoli, 1992; Lowe et al., 1995; Domouhtsidou et al., 2004), and reduction of lysosomal stability is directly linked with impaired cellular immunity (Rickwood and Galloway, 2004; Moore, 2009). For risk-assessment of nanomaterials it will be necessary to understand more about the fate of these materials both in the aquatic environment and also within complex multi-organ organisms (Oberdörster et al., 2005; Klaine et al., 2008; Tedesco and Sheehan, 2010; Elsaesser and Howard, 2012; Sharifi et al., 2012; Kahru and Ivask, 2013). "

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    • "Acetylcholinesterase (AChE) regulates cholinergic nervous transmission by hydrolysis of the neurotransmitter acetylcholine. However, in presence of certain pollutants AChE activity is inhibited and causes the alteration of the nerve impulse (Rickwood and Galloway, 2004.). Regarding physiological biomarkers, the measurement of potential somatic and gonadal growth, has also achieved an advanced level of development . "
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    ABSTRACT: This study undertakes an overall assessment of pollution in a large region (over 2500 km of coastline) of the N-NW Spanish coast, by combining the use of biochemical (AChE, GST, GPx) and physiological (SFG) responses to pollution, with chemical analyses in wild mussel populations (Mytilus galloprovincialis). The application of chemical analysis and biological techniques identified polluted sites and quantified the level of toxicity. High levels of pollutants were found in mussel populations located close to major cities and industrialized areas and, in general, average concentrations were higher in the Cantabrian than in the Iberian Atlantic coast. AChE activities ranged between 5.8 and 27.1 nmol/min/mg prot, showing inhibition in 12 sampling sites, according to available ecotoxicological criteria. GST activities ranged between 29.5 and 112.7 nmol/min/mg prot, and extreme variability was observed in GPx, showing activities between 2.6 and 64.5 nmol/min/mg prot. Regarding SFG, only 5 sites showed 'moderate stress' (SFG value below 20 J/g/h), and most sites presented a 'high potential growth' (>35 J/g/h) corresponding to a 'healthy state'. Multivariate statistical techniques applied to the chemical and biological data identified PCBs, organochlorine pesticides and BDEs as the main responsible of the observed toxicity. However, the alteration of biological responses caused by pollutants seems to be, in general, masked by biological variables, namely age and mussel condition, which have an effect on the mussels' response to pollutant exposure.
    Marine environmental research 10/2013; 96. DOI:10.1016/j.marenvres.2013.09.015 · 2.76 Impact Factor
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    • "AChE activity is inhibited by several toxicants such as organophosphate and carbamate pesticides, leading to severe physiological impairment in marine organisms (e.g. Ozmen et al., 1999; McHenery et al., 1997; Rickwood and Galloway, 2004; Tsangaris et al., 2010). Thus, the inhibition of AChE activity in mussels has been frequently used as a biomarker of chemical pollution by metals and pesticides (e.g. "
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    ABSTRACT: Biomarkers are required to assess the biological effects of pollutants on marine organisms in order to monitor ecosystem status, but their use is often limited by their strong variability due to environmental and/or intrinsic biological factors. Accordingly, the main aim of this work was to set up practical procedures for a battery of widely used biomarkers in mussels (Mytilus galloprovincialis). Antioxidant enzymes (catalase [CAT] and glutathione peroxidase [GPx]), a phase II detoxification enzyme (glutathione S-transferase [GST]) and a neurotransmitter catabolism enzyme (acetylcholinesterase [AChE]), were considered. Several relevant aspects were studied in order to obtain a more realistic interpretation of biomarker responses, including the calculation of the minimum sample size required to estimate the population mean with a fixed error margin, the selection of the specific organ or tissue where the enzymatic activity is higher for each biomarker, and the influence of tidal height and temperature on the basal enzymatic activity. GST and CAT activities needed a minimum sample size of 12, whereas for GPx and AChE activities a minimum sample size of 14 was required. The gills were the organ with higher GST, GPx and AChE enzymatic activities, whereas the digestive gland showed the highest CAT activity. Also, the low inter-tidal was the recommended tide level whilst no significant effect of temperature was observed on GST, GPx and CAT, and no clear pattern could be identified for AChE. The implications for environmental monitoring are discussed.
    Science of The Total Environment 05/2013; 461-462C:56-64. DOI:10.1016/j.scitotenv.2013.04.079 · 4.10 Impact Factor
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