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Farmaka ve vodním prostředí a jejich vliv na ryby
BURKINA, Viktoriia
In this thesis, the impact of atenolol, verapamil, dexamethasone, clotrimazole, and PBSA on the physiological condition and health of rainbow trout (Oncorhynchus mykiss) were studied in vivo and in vitro. The sub-chronic test of atenolol, including at the environmentally relevant concentration, demonstrated that only the fish exposed to atenolol at a concentration of 1000 ?g?L-1 may be at a higher risk of oxidative stress. The second pharmaceutical compound studied was an L-type calcium channel blocker, verapamil. Despite the relatively high concentration of verapamil included in the experiments, the rates of seven hepatic CYP450-mediated reactions (EROD, MROD, PROD, BFCOD, COH, and PNPH) were unchanged in the exposed rainbow trout. This indicates that the activities of the selected CYP450 enzymes were not affected. Exposure to the highest concentration of PBSA (1000 ?g?L-1) led to significantly inhibited glutathione reductase activity. The activities of the EROD, MROD, and PROD enzymes gradually increased, beginning at the environmentally relevant concentrations. We suggest that long-term exposure to PBSA could cause oxidative stress in fish, as indicated by the decreased activity of GR. Moreover, PBSA could interact with intracellular receptors due to the elevated activities of CYP1A (EROD and MROD) and CYP2B (PROD). Rainbow trout showed multiple responses after exposure to clotrimazole. Changes in the haematological parameters in the exposed rainbow trout suggested that the immune system and haemoglobin synthesis were affected. The antioxidant defence enzymes that responded to the clotrimazole exposure influenced the oxidative stress status of the fish. Sub-chronic exposure to clotrimazole did not lead to oxidative stress in any of the fish tissues studied, as indicated by the unchanged TBARS levels. Hepatic energetic pathways were activated in the tested groups after 42 days of exposure to clotrimazole. High levels of glutathione S-transferase were seen in the liver and gill tissues, possibly associated with the detoxification of clotrimazole. The interaction of clotrimazole with intracellular receptors can be expected due to the changes in the catalytic activities of CYP1A1 and CYP3A. The BCF levels in the muscle tissue suggest a moderate bioaccumulation of CLO. The relatively long elimination period for CLO in the fish kidney (half-life = 29 days) may imply a greater potential for adverse effects in this organ. This finding is significant in view of the structural disturbances that appeared in the kidney and testis. The changes observed in the kidney were most prominent in the tubular epithelial cells. Changes in the gonads were only visible in the male specimens, and the pathological changes in the testis may indicate a disruption of steroidogenesis. The potential of clotrimazole and dexamethasone to inhibit CYP450 enzyme activity in rainbow trout hepatic microsomes was investigated in vitro. Clotrimazole non-competitively inhibited EROD activity in the hepatic microsomes, while BFCOD activity was competitively inhibited. PNPH activity was only slightly reduced in the presence of clotrimazole, indicating that it does not significantly interact with CYP2E1. The presence of dexamethasone in the incubations did not affect any of the CYP450 enzymes investigated. Everything considered, the results of the study confirmed that the presence of clotrimazole in the environment is of concern with respect to its impact on the health status of fish. In this thesis, the data of the actual effects of several PPCPs on fish were discussed. Based on the response of selected molecular endpoints, the cardiovascular and anti-inflammatory drugs studied do not present a significant risk for fish, while the antifungal drug and UV-screening agent that were tested may disrupt several physiological processes in fish.
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The effect of atenolol on a fish organism
BOŘÍK, Adam
Pharmaceuticals and their metabolites are emerging pollutants of aquatic environment associated with our modern society. The aim of this bachelor's thesis was to get information about potential hazard levels of atenolol occurring in surface waters and its effects on juveniles of rainbow trout (Oncorhynchus mikyss) as a model organism. The effect of environmentally relevnt concentrations of atenolol was assased in vivo by using biochemical markers. Activity of enzymatic reactions EROD (CYP 1A), MROD (CYP 1A2) and PROD (CYP 2B) were tested as possible biomarkers. The experimental work aimed to verify wheter selected cytochromes P450 are suitable to evaluate the effects of fish exposure in natural conditions. The results of present experiment did not show a relationship between the enzymatic activity and exposure to beta-blocker atenolol. This fact implies that the enzimatic reaction EROD, MROD and PROD cannot be useful as biomarkers reflecting a metabolic response of fish after exposure to this xenobiotic.
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The distribution of rainbow trout catches during the year with respect to stocking events
ČTRNÁCT, Petr
This bachelor thesis deals with the differences between the distribution of rainbow trout catches during the year on a different fishing grounds with respect to stocking events. Angler's records from the Svitava 1 and Blanice Vodňanská 4B fishing grounds were used and elaborated for these purposes. This thesis evaluates the rate of rainbow trout return and the ratio between stocking weight and catch weight in angler's records.
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Food competition between stocked hatchery reared rainbow trout and native brown trout and grayling
BLASZCZOK, Roman
The aim of the work will be based on the diet composition monitoring of the introduced rainbow trout and wild brown trout and grayling in defined time intervals, and assessing the degree of the food competition among the monitored species. The experiment was held in the second half of September 2010 in the river Blanice in the protected fish areas close to the village Těšovice, where several dozens of rainbow trout were stocked. In a predefined several - day interval of were caught 30 pieces of the rainbow trout (SL = 266 ? 14 mm, m = 347 ? 54 g), 33 brown trout (SL = 244 ? 19 mm, m = 219 ? 51 g), 14 graylings (SL = 256 ? 27 mm, m = 240 ? 91 g) and 12 resident rainbow trout (SL = 255 ? 13 mm, m = 280 ? 47 g) originated from the last plant. Within these groups a fish stomach content and consequently food selectivity was examined by using of the Ivlev's selectivity index (1961), a food competition was examined by using of the Schoener's index food overlap (1970) and the importance of various food components was examined by using of the index of preponderance according to Natarajan (1961). Rainbow trout began to ingest food immediately after the stocking into the stream and its occurrence was seen in all fish crop caught during the period. The insect (Insecta) was given as a preferential food of the rainbow trout and according to the index of preponderance (IP), it formed 54%, Trichoptera (IP) 24% and Ephemeroptera (IP) 19% orders belonged to the most preferable kinds of the food. According to the index of preponderance, gastropod (Gastropoda) formed (IP) 25% of a secondary food. The rainbow trout was accepting the same dietary components as well as the original sorts of salmonoid fish within the river. According to the index of a food overlap (S), the food competition between rainbow trout and brown trout was equal to the value of (S = 0.566) during the whole monitored period and the grayling was equal to (S = 0.520). Even though both of these values are slightly below the significant food overlap (S = 0.6), we can still say that the food competition is relatively high among these kinds.
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