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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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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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