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Effect of chronic morphine on cell survival after oxidative stress in the SH-SY5Y neuroblastoma cell line
Moutelíková, Karolína ; Hejnová, Lucie (advisor) ; Musílková, Jana (referee)
Morphine is a natural opioid which is used in medicine due to his potent analgesic and sedative effects. In the forefront of scientific interest is a chronic usage of opioids which can lead to a development of drug addiction. Morphine role in oxidative stress was described in last years. It was revealed its protective potencial by many studies. However, some studies described its pro-oxidative effect. The aim of this study was to determinate effect of chronic morphine on cell survival after oxidative stress caused by H202 analog - tBHP in the SH-SY5Y neuroblastoma cell line. The results verified morphine protective effect against oxidative stress. The highest protective effect of morphine was achieved in a concetration of 10 µM. It was desribed that morphine can induce activation of mu-opioid (MOR) and Toll-like 4 (TLR4) receptors signalling pathway on molecular level. The aim of this thesis was to evaluate the role of MOR a TLR4 in protective effect of morphine against oxidative stress by two methods. Firstly, it was used tests of oxidative stress on cell viability. The obtained results demonstrated majority role of TLR4 and minory role of MOR. Afterwards, we assesed changes in the expression of MOR a TLR4 after chronic morphine by SDS-PAGE electrophoresis. Results of these experiments did not...
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The effect of morphine on neurogenesis and neurodegeneration in rat brain
Rydzyková, Tereza ; Novotný, Jiří (advisor) ; Vodička, Martin (referee)
Morfin is a clinically used analgesic drug but also an abusive drug. It has an impact on a wide range of CNS regions (nucleus accumbens, ventral tegmentum, hippocampus, etc.) and affects their functions, e.g. cognitive functions or anxiety. Although the results of so far published studies are often contradictory, the effects on cell death and proliferation in the CNS have been demonstrated. In this work, we focused on how chronic administration of morphine and subsequent withdrawal of this drug affects neurogenesis and neurodegeneration in the rat brain and how it affects some markers involved in the addiction and post-drug-induced condition. We have succeeded in introducing immunohistochemical markers for monitoring neurogenesis (bromodeoxyuridine and doublecortin) and neurodegeneration (Fluoro-Jade C) and for detection of selected neuromodulatory peptides (cholecystokinin and neuropeptide Y). We have found that morphine may influence the process of neurogenesis and neurodegeneration, but its effects differ in different CNS structures (nucleus accumbens, hippocampus, and amygdala). Key words: Morphine, brain, rat, withdrawal syndrom, neurogenesis, neurodegeneration
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N-oxides of morphinan alkaloids
Palušák, Martin ; Dračínská, Helena (advisor) ; Chmelík, Josef (referee)
Morphinan alkaloids belong to important class of compounds acting as painkillers. Understanding of the mechanism of their action is important for improved therapy using these alkaloids, for example, through the synthesis of new analogues with improved effect. The goal of this work is to summarize existing knowledge of these compounds including information about their biosynthesis in the plants and overall effect on the organism. The goal of the practical part of the work is a determination of the relative configuration of morphinan N-oxides produced by in situ oxidation of parent alkaloids using NMR spectroscopy and molecular modelling. Relative configurations of both oxidized and non-oxidized forms of morphine, codeine and thebaine were analyzed using NMR spectroscopy. NMR spectra were analyzed to detect ratio of different N-oxide products in situ. These values were compared with results of DFT quantum chemical computation. Using correlation analysis, reliability of computational method was verified. (in Czech) Key words: NMR spectroscopy, morphine, codeine, thebaine, N-oxides, metabolism of alkaloids
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Role of glutamatergic transmission in mechanisms of addiction to morphine.
Moutelíková, Karolína ; Hejnová, Lucie (advisor) ; Červená, Kateřina (referee)
Drugs are used by mankind since ancient times. One group of these substances are opioids. Opioids have antinociceptive effects and can induce euphoria and relaxation as well. A chronic usage of opioids can lead to a development of drug addiction and phenomens like tolerance and sensitization. One of the most used opioids in medicine is morphine. Morphine is isolated from opium of poppy (Papaver somniferum). Direct effect of morphine is mediated via activation of μ- opioid receptors and their signal cascade. It was implicated that the usage of morphine affects other neurotransmmiter systems in the brain and these neurotransmmiter systems play a signifikant role in the development of addiction and other phenomena. One of these systems is an important excitatory brain system - glutamergic system. This bacherol thesis focuses on interrelationship between opioid and glutamatergic systems during addiction.There were described changes in a composition of glutame ionotropic receptors and changes in their expression as well as in expression of metabotropic glutamate receptors. These changes differ in various parts of the brain and in diverse stages of addiction on morphine too. In spite of all diferences, the results of studies indicate that glutamatergic receptors play a significant role in the development...
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Modulatory effect of monovalent ions on δ-opioid receptors
Vošahlíková, Miroslava ; Svoboda, Petr (advisor) ; Jakubík, Jan (referee) ; Kršiak, Miloslav (referee)
The exact role of opioid receptors in drug addiction and modulatory mechanism of action of monovalent cations on these receptors are still not fully understood. Our results support the view that the mechanism of addiction to morphine is primarily based on desensitization of μ- and δ-opioid receptors. Desenzitization of agonist response proceeds already at the level of G protein functional activity. Long-term exposure of rats to morphine resulted in increase of number of δ-opioid receptors and change of their sensitivity to sodium ions. Analysis of the effect of different monovalent ions on agonist binding in δ-OR- Gi1α (Cys351 -Ile351 )-HEK293 cell line confirmed the preferential sensitivity of δ-opioid receptor to sodium ions. We have distinguished the high- and low-affinity Na+ sites. Biophysical analysis of interaction of lithium, sodium, potassium and cesium ions with plasma membranes isolated from HEK293 cells with the help of fluorescent probes indicated that monovalent ions interact, in low-affinity manner, with the polar, membrane-water interface of membrane bilayer. Key words: morphine, forebrain cortex, opioid receptors, G proteins, monovalent ions, plasma membrane, fluorescence spectroscopy.
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Changes in opioid signalisation during the ontogenesis.
Hoľuková, Martina ; Hejnová, Lucie (advisor) ; Škrabalová, Jitka (referee)
Opioid receptors interact with opiate compounds, causing the inhibition of neuroexcitability. The activation of signaling pathway of opioid receptors plays crucial role in the treatment of chronic and cancer pain. Summary of the general knowledge about opioid receptors and about the development of tolerance is in the first part of this work. Next part of the thesis concerns on ontogenesis of opioid receptors and other components related to the opioid signaling pathways as age seems to have an immense influence on molecules within and related to the opioid signaling. Finally, last part of this work collects data about the influence of morphine during ontogenesis as morphine is one of the most used opiate compound used in clinical treatment. Key words Opioid receptor, signalization, ontogenesis, addiction, tolerance, morphine
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The effect of opioids on the redox state of rat myocardium
Jandová, Gabriela ; Novotný, Jiří (advisor) ; Roubalová, Lenka (referee)
The aim of this work was to study the expression of proteins involved in reactions in which harmful free radicals are degraded in an organism. was observed difference between the expression of selected myocardial proteins in non-influenced animals, animals who were treated with low dosage of morphine (0.1 mg/kg/day or 1 mg/kg/day), and animals administered high dosage of morphine (10 mg/kg/day). Low dosages were administered for 28 days and high dosage for 10 days. In addition, the effect of abstinence lasting one week was assessed after cessation of morphine administration (1 mg/kg/day). Morphine at low dosage (0.1 mg/kg/day) increased levels of glutathion peroxidase-1/2, which may be considered as one of the possible consequences of the ongoing oxidative stress. There were no significant differences in glutathion peroxidase-6 expression. Next aim of this work was to study the expression of antioxidant enzymes. These experiments were carried out on myocardial preparations from the animals treated with a constant dosage of morphine (10 mg/kg/day) for 10 days. Samples from these animals were used for measuring the total antioxidant capacity of the left and right ventricles. These samples were also used for determination of concentration of the oxidative stress marker 8-isoprostane. We also aimed to...
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Functional activity of opioid receptors in membrane domains
Cechová, Kristína ; Hudeček, Jiří (advisor) ; Mrízová, Iveta (referee)
7 ABSTRACT In this Thesis, we examined the influence of morphine administration to the laboratory rats on the amount of µ-opioid receptors and caveolins in their cerebral cortex. Effect of morphine is known to be caused by its binding to opiod receptors, in particular to the µ subtype, and a long-term exposure to morphine reduces the functionality and number of these receptors as part of the resulting tolerance and addiction. Caveolins are proteins essential for formation of the membrane microdomains of caveolae, although it is known today that presence of these proteins is not limited to caveolae and their function is probably independent of these domains (they may participate in the regulation of cell signaling pathways, lipid transport, etc.). The function of caveolins in brain cells is not precisely known yet. In the experimental part of this work, we used the Western blot method to estimate the presence of caveolin-1 and caveolin-2 in the cerebral cortex of the rats after ten-days morphine application and in control animals. A significant increase of caveolin-1 was observed after morphine treatment as compared to control animals; a smaller, non-significant increase of caveolin-2 was also found. The amount of μ-opioid receptors in morphine affected animals was significantly decreased compared to...
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Methadone Maintenance Treatment - The pharmacokinetics and the pharmacodynamics as a basis.
Pajorová, Júlia ; Hejnová, Lucie (advisor) ; Melkes, Barbora (referee)
The aim of this study was to summarize the pharmacokinetic and pharmacodynamic knowledge about methadone, and to compare it with morphine on both molecular and clinical level. Methadone and morphine are μ opioid agonists, and therefore their effect on the organism is similar. However, the existence of fundamental differences between them, is decisive for their use in clinical practice. It was discovered that on a molecular level, methadone has a higher efficiency to internalise μ receptors than morphine, moreover it's potential to form addiction and tolerance is lower. From a pharmacokinetic point of view, methadone in contrary to morphine has a much longer elimination half-life, which brings a lots of benefits and lots of disadvantages. One of the benefits is longer effect, which together with the lower potential for tolerance and addiction development, predetermined methadone to be used for maintenance therapy for patients addicted to opiates. Maintenance therapy is based on the replacement of an illegal drug (mainly heroine), for an opiate of similar nature, which on the other hand has more favourable effects on the patient (methadone). The purpose of it is to ease the development of withdrawal symptoms during therapy's first stages, and with gradual lowering of methadone dosage, to lead the...
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