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Determination of permeability and active transport of selected butyrylcholinesterase inhibitors in vitro
Machan, Radek ; Červený, Lukáš (advisor) ; Čečková, Martina (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Radek Machan Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Determination of permeability and active transport of selected butyrylcholinesterase inhibitors in vitro European Medicine Agency (EMA) and Food and Drug Administration agency (FDA) emphasise drug membrane permeability and drug-drug interactions on ABC transporters expressed in physiological barriers should be investigated for compounds in preclinical studies or for those already clinically used but evidence free. In this work we aimed to assess the capability of several experimental butyrylcholinesterase inhibitors that had been designed to treat dementia to permeate blood-brain barrier and to elucidate role of ATP-binding (ABC) cassette transporters in this transport. For this purpose, we employed in vitro bidirectional transport study across monolayers formed by polarized and highly differentiated Caco-2 cells. The permeability values gained from measurements were similar to values of several commonly used drugs for treatment of CNS disorders (e.g. antidepressants, antiepileptics). In addition, the compounds showed values of efflux ratio (basolateral- to-apical/apical-to-basolateral) approximately one...
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Model of cerebral focal cortical ischemia and its parametrization
Svoboda, Jan ; Otáhal, Jakub (advisor) ; Konopková, Renata (referee)
Title of work: Model of cerebral focal cortical ischemia and its parametrization Work objectives: The aim of this diploma thesis was to apply modified model of focal cortical brain ischemia induced by phototrombosis and subsequently determinate its parameters. Methods: Intravenous application of photosensitive Rose Bengal dye was followed by continual illumination of green laser beam over the left sensorimotocortex for 10 minutes. Following illumination, the dye is activated and produces singlet oxygen that damages components of endothelial cell membranes, with subsequent platelet aggregation and thrombin formation, which eventually determines the interruption of local blood flow. This approach, initially proposed by Rosenblum and El-Sabban in 1977, was later improved by Watson in 1985 in rat brain. For histological evaluation of ischemic brain damage, animals were overdosed with urethane and transcardially perfused. Results: Histological examination of brains showed significant ischemic damage in all experimental animals. Lesion was located in left hemisphere and penetrated thought the grey matter in various extents. Size of lesion, its localization and depth has shown only a small variability in the individual groups. Noticeable differences were found right after comparing experimental groups....
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Acute neuroinflammatory reaction after focal cerebral ischemia
Ambrož, Ondřej ; Otáhal, Jakub (advisor) ; Konopková, Renata (referee)
Title: Acute neuroinflammatory reaction after focal cerebral ischemia Aim: The aim of this thesis is to evaluate neuroinflammatory response after focal cerebral cortical ischemia. Also, familiarizing with the method of displaying damage of blood brain barriers, neurons and the possibility of detection of microglia cells as a marker of acute neuroinflammatory processes. Methodology: This is an experimental study. We brought about cortical cerebral ischemia in rats using an application of photosensitive dye "bengal red," and a green laser. Two animals were were given the additional application of "Evans blue" in order to visualize the defects of the blood brain barrier. The animals were returned to their cage for the time needed before they were induced terminal anesthesia. This was followed by the process of brain perfusion, slicing the brain in sections 50 µm thick and then applied these sections onto slides. Sections with applied EB were immediately analyzed under the microscope. Sections to illustrate neuronal death were immunohistochemically stained via the Nissl method. Sections visualizing microglial activity were stained using CD11b antibody. Results: Following the induction of focal ischemia there occured brain tissue damage. In the vicinity of lesion there is degeneration of neurons and...
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HPLC determination of oximes in biological samples
PROCHÁZKA, Petr
Reactivators of acetylcholinesterase inhibited by organophosphate inhibitors play an important role in organophosphate poisoning therapy. There are a large number of reactivators being tested for their ability of penetration through blood-brain barrier (BBB) nowadays. The main aim of this thesis is to test this ability in four well know reactivators {--} HI-6, K-027, K-074 and TO-032. The 5% lethal dose (LD50) {--} therapeutic dose - of each reactivator was i.m. (intramuscularly) applied to experimental animals (Wistar rats) into right posterior thighs. Then the animals were sacrificed and the blood (plasma) and brain were collected for HPLC analysis. Subsequently, brain and plasma were frozen at -80 °C and stored until the assay. The reactivator concentrations were measured in plasma and four parts of the brain {--} frontal cortex (FC), basal ganglia (BG), ponto-medullar part (PM) and cerebellum (Ce). There were five animals for each group used for the purpose of the experiment. The concentrations of reactivators in plasma and blood samples were measured using HPLC-UV/VIS methodology. HI-6 concentrations CFC were on the average 4.29% of Caverage in plasma, CBG were on the average 1.9% of Caverage in plasma, CPM were on the average 2.3% of Caverage in plasma, and CCe were on the average 1.85% of Caverage in plasma. These rates were counted from all concentrations within the scope of particular observed parts of the brain. All the other tested reactivators were not quantified in brain at all.
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