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Vliv chronické expozice chloridazonu a jeho metabolitu chloridazon desphenylu na raka signálního
MATERNA, Jan
The aim of this thesis was to evaluate the effect of chloridazon (Ch) and its major metabolite chloridazon desphenyl (Ch-D) at environmentally relevant concentrations 0.45 micrograms/l (Ch1; Ch-D1) and 2.7 micrograms/l (Ch2; Ch-D2) on adult signal crayfish (Pacifastacus leniusculus). The exposure was 30-day and followed by a 15-day depuration period. The effect of the tested substances was evaluated on the basis of behavior, biochemical profile of hemolymph, biomarker of oxidative stress and antioxidants parameters. The tested substances did not effect on the behavior of crayfish. Chloridazone at concentration 2.7 micrograms/l (Ch2) caused a significant (P<0.01) increase of glucose (GLU), lactate (LACT), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity in haemolymph of crayfish and changes in catalase (CAT) levels in the gills and the hepatopancreas, compared to controls. Crayfish exposed to chloridazon in both tested concentrations (0.45 micrograms/l and 2.7 micrograms/l) showed significantly (P<0.01) higher level of reduced glutathione (GSH) in hepatopancreas and gills compared to control. Exposure of chloridazon desphenyl at concentration 0.45 micrograms/l and 2.7 micrograms/l caused significantly (P<0.01) higher levels of glucose, lactate, ammonia (NH3), calcium (Ca), alanine aminotransferase and aspartate aminotransferase activity in haemolymph of exposed crayfish compared to control. Chloridazon desphenyl in both tested concentrations caused significant (P<0.01) changes in the levels of lipid peroxidation (LPO) in the hepatopancreas and catalase (CAT) and GSH level in the gills and hepatopancreas compared to the control group. Some effects persist after a depuration period. The results showed that the metabolite chloridazon desphenyl has more pronounced effects on the physiology of adult signal crayfish than its parent compound chloridazon. It can be stated, that chloridazon and its metabolite chloridazon desphenyl has the strongly negative and harmful effects of on crayfish as representatives of non-target aquatic organisms.
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Vliv herbicidu s-metolachloru na raná vývojová stádia raka mramorovaného
MATERNA, Jan
S-metolachlor is a substance belonging to the group of herbicides, widely used in agriculture to protect crops. This substance with the chemical composition C15H22CINO2 and is used as the pre-emergent herbicides to control unwanted weeds. The aim of this work was to evaluate the influence of s-metolachlor on mortality, behavior, growth, ontogenetic development, oxidative stress level and activity of antioxidant enzymes of early developmental stages of marbled crayfish (Procambarus fallax f. virginalis). The effect of s-metolachlor was evaluated on the basis of embryo-larval toxicity test. Early developmental stages of crayfish were exposed to three concentrations of s-metolachlor, 1.1 micrograms/l, 11 micrograms/l and 110 micrograms/l for 45 days. All tested concentrations significant showed higher mortality, delay of ontogenetic development, lower growth and changes in behavior (total movement distance and movement speed). Moreover, significant decrease in catalase, glutathione-s-transferase, superoxide dismutase concentration, and reduced glutathione levels at the two higher test concentrations (11 micrograms/l and 110 micrograms/l) of s-metolachlor were observed. No significant changes in oxidative damage (TBARS levels) were observed in all the tested groups. Based on the results of this study, early developmental stages of marbled crayfish can be recommended as suitable organisms for toxicity test and their use for biomonitoring of the aquatic environment by herbicides.
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