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Farkas A, Ács A, Vehovszky Á, Falfusynska H, Stoliar O, Specziár A, Győri J. Interspecies comparison of selected pollution biomarkers in dreissenid spp. inhabiting pristine and moderately polluted sites. Sci Total Environ 2017; 599-600:760-770. [PMID: 28499224 DOI: 10.1016/j.scitotenv.2017.05.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 05/03/2017] [Accepted: 05/03/2017] [Indexed: 06/07/2023]
Abstract
Stress biomarkers, which can outline impacts of contaminants in aquatic biota at the biochemical level, are increasingly used as early warning tools in environmental monitoring. Reliable biomarker based assessment schemes, however, request appropriate knowledge of baseline levels of selected endpoints, and the potential influence of a range of natural influencing factors (both abiotic and biotic) as well. In this study, we examined the interspecies variability of various biomarkers (metallothioneins (MT), ethoxyresorufin-O-deethylase activity (EROD), lipid peroxidation (LPO), DNA strand breaks (DNA_sb), vitellogenin-like proteins (Vtg)) in Dreissena polymorpha and Dreissena bugensis inhabiting either pristine- or moderately impacted sites of Lake Balaton (Hungary). Levels of all biomarkers considered revealed low interspecies variability in the two dreissenid species at all sampling sites, with consistently higher (but statistically insignificant) values in Dreissena polymorpha. Levels of all biomarkers varied within the two investigated seasons, with significant influence of the reproduction cycle particularly on the levels of metallothioneins and vitellogenin-like proteins. Each biomarker considered was elevated by October, with significantly higher values in the mussels inhabiting harbours. Insignificant spatial and temporal variability in the general health indicators (condition index, total protein content) of dreissenids was observed, which, in parallel with evident rise in biomarker levels, apparently suggest that the anthropogenic impacts in harbours affect mussel fitness yet at sub organismal level. Our data might serve useful basis for future environmental monitoring surveys, especially in habitats where the progressive replacement of Dreissena polymorpha by Dreissena bugensis is taking place, as the interspecies variability in susceptibility to chemical stress of the two species is well comparable.
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Affiliation(s)
- A Farkas
- MTA Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3., P.O. Box 35, H-8237 Tihany, Hungary.
| | - A Ács
- MTA Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3., P.O. Box 35, H-8237 Tihany, Hungary
| | - Á Vehovszky
- MTA Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3., P.O. Box 35, H-8237 Tihany, Hungary
| | - H Falfusynska
- General Chemistry Department, Ternopil Medical State University, Maidan Voli, 1, Ternopil 46001, Ukraine
| | - O Stoliar
- Research Laboratory of Molecular Biology and Comparative Biochemistry, Ternopil National Pedagogical University, Kryvonosa Str., 2, Ternopil 46027, Ukraine
| | - A Specziár
- MTA Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3., P.O. Box 35, H-8237 Tihany, Hungary
| | - J Győri
- MTA Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3., P.O. Box 35, H-8237 Tihany, Hungary
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Ács A, Vehovszky Á, Győri J, Farkas A. Seasonal and size-related variation of subcellular biomarkers in quagga mussels (Dreissena bugensis) inhabiting sites affected by moderate contamination with complex mixtures of pollutants. Environ Monit Assess 2016; 188:426. [PMID: 27329477 DOI: 10.1007/s10661-016-5432-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 06/14/2016] [Indexed: 06/06/2023]
Abstract
The size-related differences in subcellular biomarker responses were assessed in Dreissena bugensis mussels inhabiting harbours moderately affected by pollution with complex mixtures of heavy metals and polycyclic aromatic hydrocarbons (PAHs). Adult D. bugensis samples were collected from three harbours of Lake Balaton (Hungary) characterized by moderate shipping activity, and as reference site, from a highly protected remote area of the lake. Biomarkers of exposure (metallothioneins (MTs), ethoxyresorufin-o-deethylase (EROD)), oxidative stress (lipid peroxidation (LPO), DNA strand breaks (DNAsb)) and possible endocrine disruption (vitellogenin-like proteins (VTG)) were analysed in whole-tissue homogenates of differently sized groups of mussels in relation to environmental parameters and priority pollutants (heavy metals and polycyclic aromatic hydrocarbons). Integrated biomarker response (IBR) indices were calculated for biomarker responses gained through in situ measurements to signalize critical sites and to better distinguish natural tendencies from biological effects of contaminants. Biomarker responses showed close positive correlation in case of MT, EROD, LPO, and DNAsb and negative correlation with VTG levels with mussel shell length in autumn, when higher levels of biomarkers appeared, possibly due to natural lifecycle changes of animals.
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Affiliation(s)
- A Ács
- MTA ÖK Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3, PO Box 35, Tihany, H-8237, Hungary
| | - Á Vehovszky
- MTA ÖK Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3, PO Box 35, Tihany, H-8237, Hungary
| | - J Győri
- MTA ÖK Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3, PO Box 35, Tihany, H-8237, Hungary
| | - A Farkas
- MTA ÖK Centre for Ecological Research, Balaton Limnological Institute, Klebelsberg K. u. 3, PO Box 35, Tihany, H-8237, Hungary.
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Vehovszky Á, Farkas A, Ács A, Stoliar O, Székács A, Mörtl M, Győri J. Neonicotinoid insecticides inhibit cholinergic neurotransmission in a molluscan (Lymnaea stagnalis) nervous system. Aquat Toxicol 2015; 167:172-179. [PMID: 26340121 DOI: 10.1016/j.aquatox.2015.08.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 08/14/2015] [Accepted: 08/20/2015] [Indexed: 06/05/2023]
Abstract
Neonicotinoids are highly potent and selective systemic insecticides, but their widespread use also has a growing impact on non-target animals and contaminates the environment, including surface waters. We tested the neonicotinoid insecticides commercially available in Hungary (acetamiprid, Mospilan; imidacloprid, Kohinor; thiamethoxam, Actara; clothianidin, Apacs; thiacloprid, Calypso) on cholinergic synapses that exist between the VD4 and RPeD1 neurons in the central nervous system of the pond snail Lymnaea stagnalis. In the concentration range used (0.01-1 mg/ml), neither chemical acted as an acetylcholine (ACh) agonist; instead, both displayed antagonist activity, inhibiting the cholinergic excitatory components of the VD4-RPeD1 connection. Thiacloprid (0.01 mg/ml) blocked almost 90% of excitatory postsynaptic potentials (EPSPs), while the less effective thiamethoxam (0.1 mg/ml) reduced the synaptic responses by about 15%. The ACh-evoked membrane responses of the RPeD1 neuron were similarly inhibited by the neonicotinoids, confirming that the same ACh receptor (AChR) target was involved. We conclude that neonicotinoids act on nicotinergic acetylcholine receptors (nAChRs) in the snail CNS. This has been established previously in the insect CNS; however, our data indicate differences in the background mechanism or the nAChR binding site in the snail. Here, we provide the first results concerning neonicotinoid-related toxic effects on the neuronal connections in the molluscan nervous system. Aquatic animals, including molluscs, are at direct risk while facing contaminated surface waters, and snails may provide a suitable model for further studies of the behavioral/neuronal consequences of intoxication by neonicotinoids.
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Affiliation(s)
- Á Vehovszky
- Department of Experimental Zoology, MTA Centre for Ecological Research, Balaton Limnological Institute, H-8237 Tihany, POB 35, Hungary.
| | - A Farkas
- Department of Experimental Zoology, MTA Centre for Ecological Research, Balaton Limnological Institute, H-8237 Tihany, POB 35, Hungary
| | - A Ács
- Department of Experimental Zoology, MTA Centre for Ecological Research, Balaton Limnological Institute, H-8237 Tihany, POB 35, Hungary
| | - O Stoliar
- Research Laboratory of Comparative Biochemistry and Molecular Biology, Ternopil National Pedagogical University, M. Kryvonosa Str., 2, Ternopil 46027, Ukraine
| | - A Székács
- Department of Environmental Analysis, Agro-Environmental Research Institute, National Agricultural Research and Innovation Centre, H-1022 Budapest, Herman O. u. 15, Hungary
| | - M Mörtl
- Department of Environmental Analysis, Agro-Environmental Research Institute, National Agricultural Research and Innovation Centre, H-1022 Budapest, Herman O. u. 15, Hungary
| | - J Győri
- Department of Experimental Zoology, MTA Centre for Ecological Research, Balaton Limnological Institute, H-8237 Tihany, POB 35, Hungary
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Ács A, Imre K, Kiss G, Csaba J, Győri J, Vehovszky Á, Farkas A. Evaluation of multixenobiotic resistance in dreissenid mussels as a screening tool for toxicity in freshwater sediments. Arch Environ Contam Toxicol 2015; 68:707-717. [PMID: 25801701 DOI: 10.1007/s00244-015-0150-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 03/13/2015] [Indexed: 06/04/2023]
Abstract
The multixenobiotic defense mechanism (MXR) in aquatic organisms was recognized as a first-line defense system, and its potential use as an early biomarker of exposure to environmental stress has raised attention in the last two decades. To evaluate the relevance of this biomarker in the freshwater mussel Dreissena polymorpha, we studied its responsiveness within laboratory exposures to contaminants sequestered in freshwater sediments affected by moderate anthropogenic impact. The effectiveness of this biomarker was assessed by comparing the MXR-transporter activities determined in bivalves first with toxicity scores recorded with the D. rerio embryo developmental assay. Both bioassays were applied in the sediment contact test format. As a second evaluation approach, MXR activities determined in exposed mussels were compared with sediment-contamination data integrated into toxic units on the basis of acute toxicity to Daphnia magna. In D. polymorpha subjected to acute exposure with moderately polluted sediments, we detected limited (22-33 %) but statistically significant induction of MXR activity. Mean MXR activities significantly correlated with TU values computed for test sediments. MXR activities in mussels showed strong positive correlation with the metal load of sediments and proved to be unrelated to the contamination with polycyclic aromatic compounds. MXR activity in laboratory-exposed mussels showed low variability within treatments and thus reliably reflected even low contaminant differences between the negative reference and moderately polluted harbor sediments. The strong correlation found in this study between the MXR-transporter activity in exposed mussels and environmentally realistic sediment contamination underscores the fairly good sensitivity of this biomarker in laboratory testing conditions to signal the bioavailability of sediment bound contaminants, and it may also anticipate even the incidence of toxicity to biota.
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Affiliation(s)
- A Ács
- MTA ÖK Centre for Ecological Research, Balaton Limnological Institute, Tihany, 8237, Hungary
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Vehovszky Á, Kovács AW, Farkas A, Győri J, Szabó H, Vasas G. Pharmacological studies confirm neurotoxic metabolite(s) produced by the bloom-forming Cylindrospermopsis raciborskii in Hungary. Environ Toxicol 2015; 30:501-512. [PMID: 24293352 DOI: 10.1002/tox.21927] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 06/02/2023]
Abstract
A rapid cyanobacterial bloom of Cylindrospermopsis raciborskii (3.2 × 10(4) filaments/mL) was detected early November, 2012, in the Fancsika pond (East Hungary). The strong discoloration of water was accompanied by a substantial fish mortality (even dead cats were seen on the site), raising the possibility of some toxic metabolites in the water produced by the bloom-forming cyanobacteria (C. raciborskii). The potential neuronal targets of the toxic substances in the bloom sample were studied on identified neurons (RPas) in the central nervous system of Helix pomatia. The effects of the crude aqueous extracts of the Fancsika bloom sample (FBS) and the laboratory isolate of C. raciborskii from the pond (FLI) were compared with reference samples: C. raciborskii ACT 9505 (isolated in 1995 from Lake Balaton, Hungary), the cylindrospermopsin producer AQS, and the neurotoxin (anatoxin-a, homoanatoxin-a) producer Oscillatoria sp. (PCC 6506) strains. Electrophysiological tests showed that both FBS and FLI samples as well the ACT 9505 extracts modulate the acetylcholine receptors (AChRs) of the neurons, evoking ACh agonist effects, then inhibiting the ACh-evoked neuronal responses. Dose-response data suggested about the same range of toxicity of FBS and FLI samples (EC50 = 0.397 mg/mL and 0.917 mg/mL, respectively) and ACT 9505 extracts (EC50 = 0.734 mg/mL). The extract of the neurotoxin-producing PCC 6506 strain, however, proved to be the strongest inhibitor of the ACh responses on the same neurons (EC50 = 0.073 mg/mL). The presented results demonstrated an anatoxin-a-like cholinergic inhibitory effects of cyanobacterial extracts (both the environmental FBS sample, and the laboratory isolate, FLI) by some (yet unidentified) toxic components in the matrix of secondary metabolites. Previous pharmacological studies of cyanobacterial samples collected in other locations (Balaton, West Hungary) resulted in similar conclusions; therefore, we cannot exclude that this chemotype of C. raciborskii which produce anatoxin-a like neuroactive substances is more widely distributed in this region.
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Affiliation(s)
- Á Vehovszky
- Department of Experimental Zoology, MTA Centre for Ecological Research, Balaton Limnological Institute, H-8237, Tihany, POB 35, Hungary
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Vehovszky A, Kovács AW, Szabó H, Győri J, Farkas A. Neurotoxic effects evoked by cyanobacterial extracts suggest multiple receptors involved in electrophysiological responses of molluscan (CNS, heart) models. Acta Biol Hung 2012; 63 Suppl 2:160-70. [PMID: 22776489 DOI: 10.1556/abiol.63.2012.suppl.2.21] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The responses of the snail central neurons (Helix pomatia, Lymnaea stagnalis) and the isolated Helix heart were characterized evoked by cyanobacterial extracts (Cylindrospermopsis raciborskii ACT strains) isolated from Lake Balaton (Hungary). The nicotinergic acetylcholine (ACh) receptors in the CNS (both excitatory and inhibitory) were blocked by the extracts of ACT 9502 and ACT 9505 strains and the anatoxin- a (homoanatoxin-a) producing reference strain of Oscillatoria sp. (PCC 6506), similar to the inhibitory effects of the pure anatoxin-a. The enhancement of the ACh responses by the ACT 9504 extract suggests additional, probably acetylcholine esterase inhibitory mechanisms. On the isolated Helix heart the crude ACT 9505 and PCC 6506 extracts evoked frequency increase and transient twitch contraction, opposite to the ACh evoked heart relaxation. Anatoxin-a similarly contracted the heart but did not increase its contration frequency. These data suggest the involvement of some non-cholinergic mechanisms, acting very likely by direct modulation of the electrical or contractile system of the isolated heart. Diversity of the effects evoked by the cyanobacterial extracts in the CNS and heart suggest pharmacologically different neuroactive components among the secondary metabolites of the cyanobacteria acting on both (anatoxin-a like) cholinergic and (unidentified) non-cholinergic receptors.
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Affiliation(s)
- Agnes Vehovszky
- MTA Centre for Ecological Research, Balaton Limnological Institute, P.O. Box 35, H-8237 Tihany, Hungary.
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Hernádi L, Vehovszky Á, Győri J, Hiripi L. Neuronal background of activation of estivated snails, with special attention to the monoaminergic system: a biochemical, physiological, and neuroanatomical study. Cell Tissue Res 2007; 331:539-53. [DOI: 10.1007/s00441-007-0522-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Accepted: 09/20/2007] [Indexed: 11/29/2022]
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Csóti T, Győri J, Erdélyi L. Aluminum enhances the voltage activated sodium currents in the neurons of the pond snail Lymnaea stagnalis L. BIOLOGIA FUTURA 1999. [DOI: 10.1007/bf03543029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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