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Posouzení subchronické toxicity směsí pesticidů na raky
HOVORKOVÁ, Anna
Prometryn, belonging to the group of s-triazines, has been extensively used in the case of protection of maize production against broadleaf weeds and grasses. Its use was banned by the EU in 2004. Chloridazone is a pyridazone herbicide used to protect beet production and to control broadleaf weeds. Its properties increase the potential for the transfer of this pesticide to the aquatic environment. Together with its metabolites, it has been detected in groundwater in the Czech Republic. Its use in the Czech Republic has been banned since 2020. The adventitious properties and long-term use of these substances may increase the risk of contamination of non-target ecosystems by the pesticides used and their metabolites, which may form mixtures in this environment and thus have an even riskier impact on the environment. The aim of this work was to assess the subchronic toxicity of the pesticide mixture formed of the concentrations of these pesticides on the signal crayfish (Pacifastacus leniusculus) in comparison with the control and pesticides tested alone. A subchronic toxicity test of 20 days duration followed by 10 days depuration was used to obtain the results. The criteria evaluating the toxicity of the mixture were the biochemical profile of haemolymph, oxidative stress level and antioxidant enzyme activity from hepatopancreas, muscle and gill samples. The biochemical profile of haemolymph was significantly affected in individuals tested in the pesticide mixture. For biomarkers altered due to the mixture, suppression of the effect of prometryn in the mixture was observed in some cases. The analysis of antioxidant biomarkers did not show a higher toxicity of the mixture over the pesticides tested alone. In the case of antioxidants, a greater effect was observed for prometryn tested alone, where in some cases its presence in the mixture suppressed the effects of chloridazon in the mixture.
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Sublethal effects of pesticide mixtures on crayfish
HOVORKOVÁ, Anna
Prometryn, a triazine herbicide, was banned in Europe in 2004. Metazachlor, a chloracetamide used to treat mainly oilseed crops, is one of the herbicides still in use. Individual pesticides or their metabolites can cause adverse effects in the aquatic environment, and the resulting mixtures of pesticides that can form in the environment are another issue in terms of adverse effects in the environment. The aim of this study was to assess the effect of mixtures of pesticides mixed from selected concentrations (0.01 mg.l-1, 0.1 mg.l-1, 1 mg.l-1). Pesticides were also tested individually at selected concentrations. The biochemical profile of hemolymph and antioxidant biomarkers and oxidative stress biomarker in hepatopancreatic, muscle and gill tissues of marbled crayfish were determined. Toxicity was assessed using a subchronic toxicity test performed over a period of 8 days. Metazachlor concentrations (0.1 and 1 mg.l-1) caused decreasing ALT, Cl-, Mg2+ and Ca2+ levels and increasing NH3 levels in hemolymph. The effect of all tested mixtures was observed on the increase of GLO, ALT and NH3 levels, here a synergistic effect of the mixtures was observed. The activity of antioxidant biomarkers was affected only in CAT for prometryn (0.01 mg.l-1) and metazachlor (0.01 and 1 mg.l-1). LPO levels were affected by metazachlor (0.01 mg.l-1). There was no effect of pesticide mixtures on LPO levels and antioxidant enzyme activities.
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Akutní a chronické působení neonikotinoidových látek na vodní organismy
STROUHOVÁ, Alžběta
Neonicotinoids, synthetic substances derived from the natural alkaloid nicotine, are one of the newest class of pesticides. Neonicotinoids are selective for invertebrate nicotinic acetylcholine receptors (nAChRs) and are widely used to treat crops around the word. The aim of this study was to evaluate acute and chronic toxicity of neonicotinoid substance acetamiprid and neonicotinoid product Mospilan 20 SP, which contains 20 % of acetamiprid, to aquatic organisms. Chronic effects to the biochemical profile of haemolymph, oxidative stress biomarker and antioxidant biomarkers have been evaluated too. Marbled crayfish (Procambarus virginalis) was used as a model organism to provide the toxicity. The acute toxicity (96hLC50) of the pure neonicotinoid substance acetamiprid to marbled crayfish is 0.8 mg.l-1, of Mospilan it is 2.71 mg.l-1. The theoretical acute toxicity of Mospilan is 4.0 mg.l-1. It was calculated based on the acute toxicity of pure acetamiprid as the active substance of Mospilan. Additives in the preparation probably contributes its toxicity more than the active substance itself. Acetamiprid and Mospilan impact on changes in the levels of biomarkers of the biochemical profile of haemolymph, biomarker of oxidative stress and antioxidant biomarkers. Changes in the levels of biomarkers are already manifested at concentrations corresponding to 0,1 % and 1 % of 96hLC50. These changes include increases in GLU, AST, ALT and LDH levels, decreases in CAT and GST activity and changes in LPO level.
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Vliv koncentrace, teploty a doby působení na biochemické parametry raka mramorovaného (Procambarus fallax f. virginalis) exponovaného neonikotinoidovému pesticidu, thiaklopridu
HUMMELOVÁ, Světlana
The aim of this work was to evaluate the effect of concentration, water temperature conditions and duration of action of thiacloprid on biochemical parameters of marbled crayfish (Procambarus virginalis). The time of this experiment was taken for 56 days (28 days of exposure and 28 days of depuration). Crayfish were divided into groups according to selected concentrations: control group without thiacloprid (K), highest detected environmental concentration 4.5 ?g?l-1 (TEN) and concentration 64.6 ?g?l-1 (TLC) (10 % of the 96-hour lethal concentration for marbled crayfish) and different water temperatures (17 and 23 °C). Crayfish, which was exposed to a lower water temperature conditions (17 °C) during the experiment, have been generally shown lower activity in behaviour against crayfish exposed to a higher temperature (23 °C). The effect of concentrations of thiacloprid (4.5 and 64.6 ?g?l-1) caused in the muscle and hepatopancreas LPO and changed GST activity. Statistically significantly (P<0.01) changes were observed in all tissues (muscle, hepatopancreas and gills), caused by effect of concentrations of thiacloprid (4.5 and 64.6 ?g ? l-1) and temperature condition (17 and 23 °C) during the experiment in SOD, CAT and GSH. The effect of thiacloprid concentration, water temperature condition and duration of action caused in haemolymph significantly (P<0.01) increase in GLU, NH3, AST, ALT and CK. Other parameters in haemolymph (LDH, TP, Ca2+, Mg2+) were affected only by the water temperature condition. Crayfish in higher water temperature condition (23 °C) showed higher values of these indicators in opposite to crayfish in colder temperature condition (17 °C). No different changes in haemolymph were observed only in two parameters (ALB and GLOB). The highest statistically significantly (P <0.05) changes of individual parameters inside each one group were observed especially after 14 and 28 days of exposure. Especially in higher concentration of thiacloprid and temperature was found that 28 days of depuration time was not sufficient to balance biochemical parameters to normal control values. At the end, it is apt to mention that water temperature condition had influence on individual parameters themselves, when in several cases different values of monitored biomarkers were measured between temperatures in groups exposed to the same concentrations of thiacloprid, even though their control groups showed no differences between temperatures. The results of this work confirm the synergistic effect of thiacloprid, temperature and duration of action on non-target aquatic organisms and could be used for other studies to evaluate the effect of thiacloprid and other pesticides on organisms.
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Studium adipokinetické hormonální odpovědi na infekci způsobenou entomopatogenní houbou druhu \kur{Isaria fumosorosea}
ČERNÝ, Jan
The goal of this bacholar thesis was to find out how to elicite the infection by entomopathogenic fungus Isaria fumosoroesa in the firebug Pyrrhocoris apterus. When firebugs were successfully infected by blastospors of these fungus, the level of AKH in the central neural system and metabolic activities were measured. The results revealed that the infection caused decrease of AKH level in the CNS and activation of energy sources (lipids) in haemolymph. The flow cytometry analyses indicated certain changes of hemocyte numbers and populations in the hemolymph after the infection.
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Identification and biochemical characterization of lectins in the hemolymph of three species of tick in the genus \kur{Rhipicephalus}
FIŠER, Miroslav
Lectins are tissue specific carbohydrate binding proteins with possible functions in invertebrate immunity and pathogen transmission. The main goal of this study was to identify hemolymph lectins in three different tick species. Three proteins with molecular weights of 58 kDa, 75 kDa and 180 kDa were detected in all investigated species using antibodies directed against hemagglutination activity of Rhipicephalus appendiculatus hemolymph. These proteins were characterized by biochemical methods such as Schiff/periodate staining, lectin blotting, enzymatic deglycosylation, hemagglutination analysis, immunoblotting, and mass spectrometry.
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