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The effect of selected endocrine disruptors on cytochromes P450 1B1 and 3A1/2
Holecová, Jana
Many exogenous and endogenous compounds are referred to as endocrine disruptors (EDCs), as they interfere with natural synthesis, signaling and metabolism of endogenous hormones. Common exogenous endocrine disruptors are benzo(a)pyrene (BaP) and 17α-ethinylestradiol (EE2). Endogenous endocrine disruptor 17β-estradiol (E2) is frequently present in the environment as well. In this thesis, the effect of the mentioned EDCs and their combinations on gene and protein expression of CYP1B1, 3A1 and 3A2 in rat liver, kidney and lung was determined. Protein expression was studied using Western blot method and specific antibodies; gene expression was assessed by quantitative PCR. Moreover, the effect of tested EDCs and their combinations on BaP metabolism and CYP3A specific activity (measured as testosterone 6β-hydroxylation) were studied in liver microsomal samples. It was confirmed, that BaP significantly increases CYP1B1 expression in rat liver and lung both alone and together with EE2 or E2. Pretreatment of rat with E2 and BaP increases the ability of BaP to induce CYP1B1 expression. On the contrary, EE2, E2 and their combination decrease the CYP1B1gene expression. The rate of BaP metabolites formed in liver microsomal samples increases in rats pretreated with BaP and its combinations. In liver, there was...
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Technologie výroby a hodnocení jakosti tepelně opracovaných masných výrobků
Novotná, Ivana
Heat-treated meat products are the most important group of meat products, as the range of products and popularity among consumers. The introductory part of this thesis describes the clasification of meat products according to traditional division, and especially according to legislation. The raw materials are the basis of quality for the production of high quality meat products, The most important is the meat itself, as well as additives such as spices, salt mixtures, protein and carbohydrate additives, colouring and polyphosphates. The thesis describes the process of production of this product group. Most described is heat treatment, especially smoking. Smoking is one of the basic technological processes in the meat industry. It is a method of heat treatment, preservation and aromatization of food by smoke. Smoke and its composition affect the characteristic of the final product and gives sensory benefits to the product. On the other hand, it also contains harmful substances such as polycyclic aromatic hydrocarbons. Sensory, laboratory and microbiological methods are used to evaluation the quality of meat products. Sensory evaluation takes place during shoping and consuming by customers themselves or by trained evaluators during quality control in the production process. Laboratory and microbiological methods are important for evaluation the correct composition of the product and its healthiness.
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Microbial degradation of high-molecular polycyclic aromatic hydrocarbons
Bachmannová, Christina ; Cajthaml, Tomáš (advisor) ; Mikušová, Gabriela (referee)
Polycyclic aromatic hydrocarbons are anthropogenic pollutants of the environment that reprsent danger to human health. Thus, there is a great need for knowledge of their degradation mechnaims that could be utilized for bioremediation of the contaminated environment. Polycyclic aromatic hydrocarbons with higher molecular weight are rather insoluble substances with very low bioavailability and one of them i.e. benzo[a]pyrene was found to cause carcinogenic effects and other polycyclic aromatic hydrocarbons are potential carcinogens. In this thesis, I describe information of microbial degradation pathways of suspected carcinogens such as benzo[a]pyrene, benz[a]nthracene, dibenz[a]anthracene, benzo[k] fluoroanthene, benzo[b]fluoroanthene, chrysene and indeno[1,2,3-c,d]pyrene. I also discuss enzymes of degradation pathways, namely ring-hydroxylating dioxygenases, dihydrodiol dehydrogenases, ring-cleaving dioxygenases and their adaptations to catabolism of heavy polycyclic aromatic hydrocarbons. Key words: polycyclic aromatic hydrocarbons, Pseudomonas, biodegradation, benzo[a]pyrene
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The effect of selected endocrine disruptors on cytochromes P450 1B1 and 3A1/2
Holecová, Jana
Many exogenous and endogenous compounds are referred to as endocrine disruptors (EDCs), as they interfere with natural synthesis, signaling and metabolism of endogenous hormones. Common exogenous endocrine disruptors are benzo(a)pyrene (BaP) and 17α-ethinylestradiol (EE2). Endogenous endocrine disruptor 17β-estradiol (E2) is frequently present in the environment as well. In this thesis, the effect of the mentioned EDCs and their combinations on gene and protein expression of CYP1B1, 3A1 and 3A2 in rat liver, kidney and lung was determined. Protein expression was studied using Western blot method and specific antibodies; gene expression was assessed by quantitative PCR. Moreover, the effect of tested EDCs and their combinations on BaP metabolism and CYP3A specific activity (measured as testosterone 6β-hydroxylation) were studied in liver microsomal samples. It was confirmed, that BaP significantly increases CYP1B1 expression in rat liver and lung both alone and together with EE2 or E2. Pretreatment of rat with E2 and BaP increases the ability of BaP to induce CYP1B1 expression. On the contrary, EE2, E2 and their combination decrease the CYP1B1gene expression. The rate of BaP metabolites formed in liver microsomal samples increases in rats pretreated with BaP and its combinations. In liver, there was...
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The effect of selected endocrine disruptors on cytochromes P450 1B1 and 3A1/2
Holecová, Jana ; Bořek Dohalská, Lucie (advisor) ; Cajthaml, Tomáš (referee)
Many exogenous and endogenous compounds are referred to as endocrine disruptors (EDCs), as they interfere with natural synthesis, signaling and metabolism of endogenous hormones. Common exogenous endocrine disruptors are benzo(a)pyrene (BaP) and 17α-ethinylestradiol (EE2). Endogenous endocrine disruptor 17β-estradiol (E2) is frequently present in the environment as well. In this thesis, the effect of the mentioned EDCs and their combinations on gene and protein expression of CYP1B1, 3A1 and 3A2 in rat liver, kidney and lung was determined. Protein expression was studied using Western blot method and specific antibodies; gene expression was assessed by quantitative PCR. Moreover, the effect of tested EDCs and their combinations on BaP metabolism and CYP3A specific activity (measured as testosterone 6β-hydroxylation) were studied in liver microsomal samples. It was confirmed, that BaP significantly increases CYP1B1 expression in rat liver and lung both alone and together with EE2 or E2. Pretreatment of rat with E2 and BaP increases the ability of BaP to induce CYP1B1 expression. On the contrary, EE2, E2 and their combination decrease the CYP1B1gene expression. The rate of BaP metabolites formed in liver microsomal samples increases in rats pretreated with BaP and its combinations. In liver, there was...
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The effect of selected endocrine disruptors on the cytochromes P450 1A1 and 2C
Klusoňová, Zuzana ; Bořek Dohalská, Lucie (advisor) ; Linhartová, Lucie (referee)
Many currently produced chemicals reveal specific properties which allow them to be referred to as endocrine disruptors (ED). These substances exhibit an exogenic hormone activity and usually act as antagonists or agonists of endogenic hormones. The exogenic EDs studied in this work were 17α-ethinylestradiol (EE2) and benzoapyrene (BaP). 17β-estradiol (E2), a typical endogenic hormone, was also included to the study. In the presented work, the effect of these EDs and their combinations on the expression and specific activities of cytochromes P450 (CYP) 1A1 and 2C was determined. First, the microsomal fraction (MF) of liver, kidney and lung of rats premedicated with these compounds or without premedication was isolated. CYP expression was assessed by the Western blot analyses in these MF samples. Moreover, CYP1A1 and CYP2C specific activities were evaluated. It was found that premedication of rats with BaP increased CYP1A1 expression in all above mentioned organs. Whereas BaP strongly induced rat CYP1A1, EE2 and E2 were almost without this effect. But, when these disruptors were administered to rats with BaP, they supported its potency to induce CYP1A1. Further, CYP2C11 expression and its specific activity were gently increased by premedication of rat with EE2 and its combination with BaP....
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The contents of selected persistent organic pollutants in soils at selected locations within Hradec Králové city
Bartošová, Barbora ; Száková, Jiřina (advisor) ; Radim, Radim (referee)
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants entering the environment from both natural and anthropogenic sources. The main anthropogenic sources are processes for the production of electricity and thermal energy, waste incineration, road traffic and motor vehicles, aircraft, boats, steam and diesel-electric locomotives and some industrial technologies. Besides these main sources there are still a number of others, less important, e.g. working with hot tar, asphalt pavement wear and tire during vehicle operation, coking plants, plants for processing of oil and some metals plants. An indispensable source in the cities as domestic solid fuel burning furnaces.
Although Hradec Králové do not belong to the cities with extreme levels of contaminants in the air, according to the Czech Hydrometeorological Institute, the levels of benzo(a)pyrene in the case of annual average concentrations exceeding the maximum allowable concentrations occurred here in 2013. While air quality is monitored regularly, the PAHs contents in soils and vegetation are not so. In our simple single experiment, we decided to assess the level of contamination of soil PAHs in the land of Hradec Kralove. It was collected 86 soil samples, in which were determined contents of 16 PAHs. Further, mushroom fruit samples that were found in the individual sampling points were analyzed.
The results showed large variability of PAHs content in the city, but did not indicate significant levels of contamination. The sum of all the determined PAU does not exceed the permissible value of the contents of these elements in soils. However, in several cases exceeding the maximum allowable content in soils with different PAHs, especially fluoranthene, anthracene and chrysene. Linear correlation analysis showed that the levels of all monitored PAHs are close correlations, which indicates that the entire spectre of PAHs in this case always originates from the same source. The PAH contents in mushrooms were in most cases below the detection limit of the determination, only rarely the detectable contents of individual PAHs were found (Cylocybe gambosa, Agaricus arvensis). We can speculate about the limited ability of fungi to accumulate PAHs or their ability to degrade these substances.
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