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Interaction of selected antiepileptics with MRP2 transporter
Bačová, Jitka ; Pávek, Petr (advisor) ; Trejtnar, František (referee)
(English version) Purpose: Based on recent studies, which have determinated overexpression of efflux transporter MRP2 in blood-brain barier of patients with refractory epilepsy, it has been suggested that this overexpression could contribute to the farmacoresistance to antiepileptic drugs. The aim of our study was to test substrate affinity of selected antiepileptic drugs. In particular, we focused on phenobarbital, phenytoin, ethosuximide, primidone, valproate, carbamazepin, clonazepam and lamotrigin. Furthermore, the inhibitory potency of these antiepileptic to MRP2 was examined. Methods: To study substrate affinity of tested antiepileptic to MRP2, transport experiments were performed in epithelial cell monolayers cultivated on mikroporous membrane filtres. Particulary, MDCKII cells transfected with cDNA of human MRP2 and, as a control, MDCKII-NeO cells where the expression of MRP2 is supressed, were used. For detection of inhibitory potency of the antiepileptic drugs to MRP2, accumulation assays were carried out on MDCKII-MRP2 and MDCKII-NeO cell lines using calcein as a known fluorescent substrate of MRP2. Results: The tested antiepileptic drugs are neither substrates nor inhibitors of MRP2. Conclusion: Our data do not support the hypothesis that the overexpression of MRP2 in blood- brain...
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Attitudes and experience of the university students with drugs of abuse
Mašová, Veronika ; Pávek, Petr (advisor) ; Višňovský, Peter (referee)
CHARLES UNIVERSITY IN PRAGUE FACULTY OF PHARMACY IN HRADEC KRÁLOVÉ ATTITUDES AND EXPERIENCE OF STUDENTS WITH ADDICTIVE SUBSTANCES: Attitudes of the third year undergraduate pharmacy students of Charles University in Hradec Králové towards illegal drugs Veronika Mašová This dissertation deals with the attitudes, experience and knowledge of illegal drugs. The study targets to the third year undergraduate pharmacy students of Charles University in Hradec Králové in academic year 2005/2006. It contains both theoretical part and practical part. In theoretical part we find basic terms, pharmacology of some addictive substances and the review of drug situation in Europe and the Czech Republic. The practical part performes the results of anonymous questionnaire. In the discussion, the result of questionnaire are compared with the results from the first year undergraduate pharmacy student in the same year. Results of search from another faculties (Prague and Brno) and ESPAD study are compared with this investigation too. 139 students take part in this search. The age interval ranged from 21 to 30 years and the mean age was 21,7 years. My study determines that the mean age, when students tried drugs for the first times, is 17,9 years. Students have the biggest experience with marijuana. It was offered to 74,5% of...
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Attitudes and experience of the university students with drugs of abuse
Stejskalová, Lucie ; Pávek, Petr (advisor) ; Višňovský, Peter (referee)
CHARLES UNIVERSITY IN PRAGUE FACULTY OF PHARMACY IN HRADEC KRÁLOVÉ ATTITUDES AND EXPERIENCE OF STUDENTS WITH ADDICTIVE SUBSTANCES: Attitudes of the third year undergraduate pharmacy students of Charles University in Hradec Králové towards the alcohol and tobacco Lucie Stejskalová This thesis investigates the attitudes, experience and knowledge of the third year undergraduate pharmacy students of Charles University in Hradec Králové in academic year 2005/2006 to legal addictive substances - alcohol and tobacco. It contains both theoretical and practical part. Theoretical part covers basic terms, possible reasons for students' drugs abuse, possibilities of drug addiction prevention, kinds of drug addiction and more detailed pharmacological information about alcohol and tobacco. The practical part is focused on anonymous questionnaire results interpretation. In the conclusion the recent results are being compared with the results of the similar study which was executed in the year 2000 at the same faculty. Gathered information is also collated with the results coming from different faculties (Prague and Brno) and ESPAD study. There were 190 students who took part in this research. The age interval ranged from 21 to 23 years and the mean age was 22.0 years. My study proves that most students have experience...
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Ovlivnění buněčné direrenciace u nádorových buněk analýzou exprese proteinu Serca3 jako markeru diferenciace
Šerá, Pavlína ; Pávek, Petr (advisor) ; Šimůnek, Tomáš (referee)
In the present work we investigated the process of cellular differentiation induced by histone deacetylase inhibitors in cell lines derived from various types of non- small cell lung cancer (NSCLC). Our objective was to study the cross-talk between the process of cellular differentiation and expression of Sarco-Endoplasmic Reticulum Calcium ATPases (SERCA proteins), enzymes that transport calcium from cytosol to the endoplasmic reticulum. Various lung cancer cell lines were grown in vitro, subjected to treatments by various short chain fatty acid-derived histone desacetylase inhibitors, and SERCA expression was determined in a semi-quantitative Western blot format using the IID8 and PLIM430 anti-SERCA monoclonal antibodies that recognise SERCA2 and SERCA3, respectively. Our experiments show that the expression of SERCA proteins and cellular differentiation are interconnected in all lung studied cancer cell lines (A549, Calu-3, ChaGoK-1, NCI-H292 and NCI-H460). In particular, the induction of the expression of SERCA3 protein was observed after the induction of cellular differentiation by histone deacetylase inhibitors such as sodium butyrate, valerate and phenylbutyrate. Induction of SERCA3 expression was specific, because SERCA2 levels were not modified by the treatments. Taken together, our...
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Principy transportu léčiv přes placentu: nové aspekty pro farmakoterapii v těhotenství
Schönwälderová, Denisa ; Čečková, Martina (advisor) ; Pávek, Petr (referee)
7.SUMMARY After thalidomide-induced birth defects affair, the view of uterus as pharmacologically unconquerable site dramatically changed. Subsequently it was accepted that any chemical substance permeates across the placenta. As there was a continuing need for many mothers to continue to receive medications for chronic disease states, extensive research was launched to gain an appropriate rationale. Progressive investigation of placental barrier compounds allowed the emergence of in vitro and in vivo models, which enabled particularly drug transport studies. Syncytiotrophoblast plays an important role as a rate-limiting component of the barrier. Detailed understanding of pharmacokinetic changes that occur during gestation offered a rationale for pharmacotherapy in pregnancy (large charged molecule, excessive protein-binding, short elimination half-life, volume of distribution, fetal-maternal serum pH gradient). The mechanism of passive diffusion is most important way of drug transport. Perfusion studies clarified the crucial role of active efflux transporters, members of ABC protein family, namely P-glycoprotein, multidrug resistence-associated proteins a ABCG2. As P- gp was first to be discovered, is the most studied until now. Its substrates and inhibitors are well defined and their interactions are...
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Study of selected drug-drug interactions of warfarin at the molecular level
Rulcová, Alice ; Pávek, Petr (advisor) ; Mladěnka, Přemysl (referee)
Xenobiotics are metabolized by hepatic biotransformation enzymes of cytochrome P450. Drug-drug interactions, where one substance increases the activity of biotransformation enzymes involved in the metabolism of other drug and accelerate its elimination, often occure in xenobiotics metabolism. The pregnane X receptor is a ligand-activated nuclear receptor, which plays central role in induction of numerous genes involved in the phase I. and II. of biotransformation including the most important hepatic enzyme CYP3A4. The aim of the diploma thesis was to examine interaction of warfarin and its enantiomers with PXR in terms of transactivation of CYP3A4 gene in hepatoma cell line HepG2 or in primary human hepatocytes. The cytotoxicity of warfarin was tested on cell line HepG2 using the MTT assay. Cytotoxic activity of warfarin didn't become evident in tested concentrations. Using the methods gene reporter assay and two-hybrid assay, we found that R-warfarin induces CYP3A4 gene expression through nuclear receptor PXR. Using the method RT-PCR, we observed induction effect of warfarin and its enantiomers on the CYP3A4 gene expression in isolated hepatocytes of two donors. I can conclude that activation of PXR by warfarin may cause pharmacokinetic drug-drug interactions of pharmaceuticals metabolized by CYP3A4.
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Role of ABC transporters in pharmacoresistant epilepsy
Hanousková, Tereza ; Pávek, Petr (advisor) ; Trejtnar, František (referee)
The diploma thesis summarizes the recent knowledge on the possible role ABC transporters in mechanisms of refractory epilepsy. Approximately 30% of patients with epilepsy are refractory to treatment. An important characteristic of pharmacoresistant epilepsy (PE) is that most patients are at the same time resistant to several antiepileptics (AED) even though these drugs act by different mechanisms. It was suggested that one of the main cause of pharmacoresistance is the decreased drug uptake into the brain mediated by multidrug transporters in the blood-brain barier (BBB). The ABC transporters studied in relation to PE are the following: P-glycoprotein (Pgp, coded by MDR1 gene), some members of the multidrug resistance protein (MRP) family and the breast cancer resistance protein (BCRP). The over-expression of the ABC transporters was demonstrated in capillary endothelial cells of BBB, and astrocytes and neurons of epileptogenic brain tissue. Therefore modulation of ABC efflux transporters of the BBB could be a novel strategy to enhance the penetration of AED into the brain. Coadministration of inhibitors with less toxicity, higher potency and specifity to Pgp together with AED could thus reverse PE and achieve seizure control in epilepsy. The characterization of variations in the MDR1 gene and...
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Implication of the Gabaergic System in Altered Responses to Stress Associated to Maternal Separation
Martišová, Eva ; Pávek, Petr (advisor) ; Štaud, František (referee)
in English language - diploma thesis Implication of the Gabaergic System in Altered Responses to Stress Associated to Maternal Separation Eva Martišová This diploma thesis studied whether the GABA system alters responses to stress induced by maternal separation in rats. The aim was to examine the influence of maternal separation on GABA neurotransmission, in particularly, the biochemical markers of the system (levels of the neurotransmitter GABA, GABA A receptor expression), and to study of gender-related differences in behavioral and neurochemical processes in rats induced by maternal separation. In order to pursue the objectives, it was necessary to develop a model of maternal separation in rats. Rat pups were separated from their mother for three hours a day from postnatal day 2 to postnatal day 21 (in the postnatal period, when the reduced ability to respond to stressful stimuli). At postnatal day 23 pups were removed from mothers, divided into groups of the same sex. Then pups were without significant manipulation left to grow into adulthood. After reaching adulthood (> 60 days) rats were divided into two groups. The first group was killed by decapitation and different brain regions (anterior and temporal cortex, corpus striatum and hippocampus) were used to determine the levels of GABA using...
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Inhibice histon-deacatyláz a mitochondriální pohyb v neuronech
Prokopová, Iva ; Pávek, Petr (advisor) ; Červený, Lukáš (referee)
1 Abstract Histone Deacetylase Inhibition and Mitochondrial Trafficking in Living Neurons Mitochondrial trafficking is necessary for proper neuronal function and its impairment leads to neurodegeneration. We have found significant differences in mitochondrial movement between cortical and striatal neurons derived from rat brain. In striatum, mitochondria move with lower average speeds and decreased overal mitochondrial dynamics than those in cortex, exhibiting the same mitochondrial fractional occupancy in neuronal processes. How this could contribute to high striatal vulnerability in neurodegeneration is discussed. We used two different methods of trafficking analysis: manual and semi-automatic. These analyses determine average movement speeds of single mitochondria, as well as overal mitochondrial dynamics in particular field. Only neurons with established synaptic connections were analyzed, mitochondria travelling in both directions were found to move with equivalent average speeds, thus not further distinguished. Our preliminary results also reveal that histone deacetylase inhibition with trichostatin A increases mitochondrial trafficking in striatal neurons, independently of mitochondrial fractional occupancy and Ca2+ levels in neuronal processes. We suggest that possible mechanism of this effect is...
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