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Vasodilatory effects of 4-methyl catechol: ex vivo mechanism of action
Kuzdřalová, Kateřina ; Pourová, Jana (advisor) ; Smutná, Lucie (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Kateřina Kuzdřalová Supervisor: doc. PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: The mechanism of vasodilation effect of 4-methylcatechol ex vivo Keywords: rat, aorta, flavonoids, 4-methylcatechol, vascular smooth muscle, vasodilation Flavonoids belong to the group of polyphenolic bioactive substances found abundantly in plants, fruits and vegetables. Thanks to their pharmacological and biochemical effects, they play a crucial role for human health, especially in the prevention of numerous diseases - metabolic syndrome, osteoporosis, atherosclerosis and also diseases of a cardiovascular system. The aim of the diploma thesis was to determine the mechanism of the vasorelaxant effect of one of the most important metabolites of flavonoids - 4-methylcatechol. For the research we used a standardized ex vivo method on isolated Wistar rat aortic rings. We were able to confirm the vasodilatory effects of 4-methylcatechol. We also confirmed the fact that the flavonoid metabolite directly affects a vascular smooth muscle. Furthermore, we found that the tested compound potentiates the vasodilatory activity of sodium nitroprusside and forskolin, and that vasodilation depends on the activity of...
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Design of Sailing Boat
Křížová, Barbora ; Řezníček, Svatopluk (referee) ; Křenek, Ladislav (advisor)
The topic of this master‘s thesis is design and analysis of a sailing boat in accordance with ergonomic and technological requirements. The goal is to create a sailing boat, which will be modern, visually interesting and which and which will take future development of both design and technology into account.
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Hydrodynamic mixing of water-ask mixture in vessel
Holub, Přemysl ; Franc, Zdeněk (referee) ; Habán, Vladimír (advisor)
Master´s thesis Hydrodynamic mixing of water-ash mixture in vessel is interested in describing fluid and solid particles flow in a vessel. The mixing was conducted in cylindrical vessel by a radial nozzle. The goal of the thesis is to describe flow field and places where the most of the particles are descending according to position, depth, flow rate and nozzle orientation in the vessel. An experiment was conducted in order to investigate and document 8 different positions and orientation of the nozzle. Significant changes in flow fields and mixing time were observed. A mathematical model of the vessel with the nozzle was created in Fluent program. Places with the lowest velocities according to the model were in good agreement with places where the most of the solid particles were descending.
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Study of the mechanisms of action of phenolic compounds on vascular smooth muscle
Alves Dias, Patrícia Alexandra ; Mladěnka, Přemysl (advisor) ; Kyselovič, Ján (referee) ; Štengl, Milan (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Training Workplace Department of Pharmacology and Toxicology Doctoral Degree Program Pharmacology and Toxicology Candidate Patrícia Alexandra Alves Dias, M.Sc. Supervisor prof. Přemysl Mladěnka, Pharm.D., Ph.D. Advisor assoc. prof. Jana Pourová, Pharm.D., Ph.D. Title of Doctoral Thesis Study of the mechanisms of action of phenolic compounds on the vascular smooth muscle Cardiovascular diseases including hypertension, coronary artery disease, peripheral artery disease, and cerebrovascular disease remain the leading cause of death worldwide. In addition, discouraging estimations have suggested a future increase in the number of cardiovascular patients. Thus, novel treatment modalities are clearly needed to prevent or reverse these epidemic trends. Phenolic compounds contain one or more hydroxyl groups bound to a benzene ring. This class of chemicals includes: a) natural compounds (e.g., dietary polyphenols and small phenolic metabolites) referred to as nutraceuticals due to their claimed health-promoting effects and b) synthetic compounds (e.g., bisphenols) which, on the contrary, have been suggested to negatively affect human health. Even if there are claims that polyphenol-rich diet is associated with cardioprotective effects, important...
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Vasodilatory effects of 3-hydroxy phenylacetic acid: ex vivo mechanism of action
Štefancová, Monika ; Pourová, Jana (advisor) ; Vokřál, Ivan (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Monika Štefancová Supervisor: doc. PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: Vasodilatory effects of 3-hydroxy phenylacetic acid: ex vivo mechanism of action It is known from clinical studies that the intake of polyphenols from food acts as a prevention of cardiovascular diseases. However, the parent compounds themselves often have low bioavailability. The emphasis is therefore on their bioactive metabolites. 3-hydroxy phenylacetic acid (3-HPAA) is among such metabolites. The aim of this study was to verify the mechanism of the vasodilatory effect of 3-HPAA using standardized ex vivo method on an isolated pig coronary artery. The administration of 3-HPAA resulted in relaxation of maximally contracted segments of porcine artery by mechanism partially dependent on the integrity of endothelium. By inhibiting endothelial nitric oxide synthase, the relaxation was significantly impaired. The blockage of SKCa and IKCa channels, muscarinic receptors, cyclooxygenase or L-type calcium channels did not affect relaxation. Thus, 3-HPPA causes dose-dependent vasodilatation of coronary arteries ex vivo at least partially mediated by endothelium with the participation of nitric oxide. Key words:...
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Vasodilatory effects of 4-methyl catechol: ex vivo mechanism of action
Kuzdřalová, Kateřina ; Pourová, Jana (advisor) ; Smutná, Lucie (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Kateřina Kuzdřalová Supervisor: doc. PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: The mechanism of vasodilation effect of 4-methylcatechol ex vivo Keywords: rat, aorta, flavonoids, 4-methylcatechol, vascular smooth muscle, vasodilation Flavonoids belong to the group of polyphenolic bioactive substances found abundantly in plants, fruits and vegetables. Thanks to their pharmacological and biochemical effects, they play a crucial role for human health, especially in the prevention of numerous diseases - metabolic syndrome, osteoporosis, atherosclerosis and also diseases of a cardiovascular system. The aim of the diploma thesis was to determine the mechanism of the vasorelaxant effect of one of the most important metabolites of flavonoids - 4-methylcatechol. For the research we used a standardized ex vivo method on isolated Wistar rat aortic rings. We were able to confirm the vasodilatory effects of 4-methylcatechol. We also confirmed the fact that the flavonoid metabolite directly affects a vascular smooth muscle. Furthermore, we found that the tested compound potentiates the vasodilatory activity of sodium nitroprusside and forskolin, and that vasodilation depends on the activity of...
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Vasodilatory effects of catechol derivatives ex vivo
Šmídová, Kristýna ; Pourová, Jana (advisor) ; Carazo Fernández, Alejandro (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Kristýna Šmídová Supervisor: doc. PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: Vasodilatory effects of catechol derivatives ex vivo Polyphenols, including flavonoids, are a broad group of natural substances with significant effects on human health, including the prevention of cardiovascular diseases. Their metabolites can also be active, with clinical effects which may even exceed those of the parent compounds. The aim of this diploma thesis was to verify vasodilatory effects of one flavonoid metabolite type, a series of catechol derivatives and elucidate the mechanism of action of the most potent substance. The established ex vivo method of isolated aortic rings of Wistar rats with isotonic registration of tissue contraction and dilation (software S.P.E.L. Advanced Kymograph Software) was used. In the experiments with the rat aorta precontracted by norepinephrin, 3-methoxycatechol was the most effective vasodilator (EC50 = 7,6 µmol.l-1). In the mechanistic study, we found out that its effect is endothelium-independent, and that 3-methoxycatechol enhances the vasodilatory effect of sodium nitropruside. However, the specific mechanism responsible for vasodilation was not identified and...
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Determination ignition temperature of flammable liquids in different conditions
SABELA, Marek
This master thesis named Determination of ignition temperature at flammable liquids under various conditions deals with atmospheric as well as specific technological, non-atmospheric, conditions. The measurements proved that the ignition temperature at luquids decreases with increasing preassure in a vessel. Based on comparison with foreign sources, it was possible to prove that even size of a vessel influences the ignition temperature. The bigger the vessel the lower the ignition temperature. The measurements are carried out in a closed vessel under isochronic conditions. This method guarantees there is no air exchange between vessel and the surroundings. To equip such measurements the Technical Institute of Fire Protection built specific facility capable of providing necessary conditions. The main goal of the experiments is to determine ignition temperature at selected flammable liquids under variable initial pressures and under various oxygen concentration and to compare the results with available sources in literature. Heptan and Pentan were chosen for this comparison and the experiments were carried out at various initial pressures of 100 kPa, 200 kPa, 500 kPa in a vessel. Apart from comparison of measured values by Technical Institute of Fire Protection along with cooperating institute PTB Braunschweig, this thesis focuses on determination of the lowest oxygen concentration at various initial pressures under which no ignition of tested flammable chemicals happens. Our experiments proved that when the atmospheric pressure in a closed vessel reaches 10%, the tested flammable liquid is not ignitable. When the measures are carried out under higher initial preassures in the vessel the oxygen percentage in the vessel is significantly lower.
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Vasodilatory effects of catechol derivatives ex vivo
Šmídová, Kristýna ; Pourová, Jana (advisor) ; Carazo Fernández, Alejandro (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Kristýna Šmídová Supervisor: doc. PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: Vasodilatory effects of catechol derivatives ex vivo Polyphenols, including flavonoids, are a broad group of natural substances with significant effects on human health, including the prevention of cardiovascular diseases. Their metabolites can also be active, with clinical effects which may even exceed those of the parent compounds. The aim of this diploma thesis was to verify vasodilatory effects of one flavonoid metabolite type, a series of catechol derivatives and elucidate the mechanism of action of the most potent substance. The established ex vivo method of isolated aortic rings of Wistar rats with isotonic registration of tissue contraction and dilation (software S.P.E.L. Advanced Kymograph Software) was used. In the experiments with the rat aorta precontracted by norepinephrin, 3-methoxycatechol was the most effective vasodilator (EC50 = 7,6 µmol.l-1). In the mechanistic study, we found out that its effect is endothelium-independent, and that 3-methoxycatechol enhances the vasodilatory effect of sodium nitropruside. However, the specific mechanism responsible for vasodilation was not identified and...
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The in vitro effects of selected fenolic substances on isolated rat vessels
Rajtmajerová, Iveta ; Pourová, Jana (advisor) ; Hrdina, Radomír (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Iveta Rajtmajerová Supervisor: PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: The in vitro effects of selected fenolic substances on isolated rat vessels Silymarin flavonolignans are endowed with various aspects. Recently their hepatoprotective effect has been discussed widely as well as their positive influence on the cardiovascular system. This diploma thesis is concerned with the vasodilatory effects of silybin-A, silybin-B, silybin-A + B and isosilybin-A on rat aorta. The aim of this study was to test the vasodilatory effect of selected substances. The dependence of aortic relaxation on the increasing concentration of tested substances was measured. Isolated Wistar breed rat aorta was used. DRC curves were created and EC50 values were assessed from the obtained values of vessel tension. The results were evaluated subsequently. The vasodilator potential of silybin-A and isosilybin-A is comparable; hence the position of the substituents may be irrelevant in having any impact on relaxation of the vessels. Different vasodilatory effects of silybin-A and silybin-B have been observed thus, the relaxation could be stereoselective. The testing of the equimolar mixture of silybin-A and...
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