|
|
Anthracycline cardiotoxicity and study of new pharmacological cardioprotectants
Pokorná, Zuzana ; Štěrba, Martin (advisor) ; Mičuda, Stanislav (referee) ; Štengl, Milan (referee)
Title: Anthracycline cardiotoxicity and study of new pharmacological cardioprotectants This Ph.D. thesis is a commented collection of 3 original articles published in international journals. The first part deals with cardiotoxicity of proteasome inhibitors (PI) bortezomib and carfilzomib, which are biologically targeted drugs with a suspected risk of cardiotoxicity and heart failure (HF). As PIs are now being combined with anthracycline (ANT) anticancer drugs, which are well known for their damaging impact on the heart, a special attention was paid to this potentially risky combination. In vitro experiments with primary cardiomyocytes yielded different results depending on the employment of either neonatal or adult rat cardiomyocyte model (NVCM and AVCM, respectively). In particular, both PIs significantly increased toxicity of ANTs to NVCM, but not to AVCM, even though they inhibited proteasome activity in AVCM even more effectively. Both PIs administered in maximally tolerated doses in combination with ANT did not have a significant impact on the development of chronic ANT cardiotoxicity and HF in rabbits. Both PIs induced significant but relatively short-lived inhibition of proteasome activity in the heart, which might explain why they did not have a significant impact on a protein homeostasis...
|
|
|
Physiological and pathological factors affecting absorption of drugs
Ryšánek, Pavel ; Šíma, Martin (advisor) ; Mičuda, Stanislav (referee) ; Dražanová, Eva (referee)
Absorption of drugs from the gastrointestinal tract after oral administration is a key pharmacokinetic process co-determining the subsequent pharmacodynamic response of the organism and therapeutic efficacy. This dissertation thesis is devoted to the study of factors that influence this parameter. Special emphasis is placed on the study of lymphatic absorption, i.e. the rate of absorption of the active substance via the intestinal lymphatic system. A number of in vivo studies have been carried out in laboratory rats. Pharmacokinetic studies have been performed by means of regular blood sampling from vascular catheters after oral administration of the drug. Lymphatic absorption was investigated in an anaesthetized mesenteric lymphatic duct cannulated rat model. Modern drugs were tested that were incorporated into innovative dosage forms by collaborating chemical and technological institutions. Abiraterone acetate, a lipophilic agent used in the therapy of prostate cancer, was well absorbed from the gastrointestinal tract after administration in the form of oil marbles. This technology also succeeded in reducing the otherwise very significant positive food-effect. Abiraterone acetate was not absorbed to any significant extent via the intestinal lymphatic system. In contrast, lymphatic absorption of...
|
|
|
Dynamics of Changes in Bile Acid Metabolomics in Estrogen-Induced Cholestasis
Alaei Faradonbeh, Fatemeh ; Mičuda, Stanislav (advisor) ; Večeřa, Rostislav (referee) ; Muchová, Lucie (referee)
Dynamics of changes in bile acid metabolomics in estrogen-induced cholestasis Bile acids are essential endobiotics with numerous exocrine and endocrine functions. In this dissertation, we evaluate three factors that were suspected of modifying bile acid metabolomics: i) the effect of metformin in estrogen-induced cholestasis, ii) the role of MRP2 (multidrug resistance-associated protein 2) protein in the described risk of more frequent intrahepatic cholestasis in pregnancy, and iii) the excessive iron accumulation in the liver. Metformin has been tested for its potential use in women with gestational diabetes mellitus (GDM) who have a higher incidence of intrahepatic cholestasis (ICP). As an ICP model, we used experimental cholestasis induced in mice by administration of ethinylestradiol. Administration of metformin in this situation significantly increased bile acid concentrations in the systemic circulation, which reached values considered significantly toxic in pregnant women. These data suggest that the possibility of developing ICP is accentuated when metformin is used in pregnant women. In another study, we demonstrated that the MRP2 transporter plays a significant role in biliary bile acid elimination and that the genetic defect itself caused an increase in the plasma concentrations in rats....
|
|
|
The effect of natural compounds on transport by OATP drug transporters
Zemčíková, Lucie ; Trejtnar, František (advisor) ; Mičuda, Stanislav (referee) ; Szotáková, Barbora (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: MSc. Lucie Zemčíková Supervisor: Assoc. Prof. PharmDr. František Trejtnar, CSc. Title of doctoral thesis: The effect of natural compounds on transport by OATP drug transporters OATP membrane transporters belong to carrier proteins responsible for transporting certain drugs (e.g. hypolipidemics from the group of statins) and other xenobiotics across the biological membranes and tissue barriers within the body. These transport proteins play an important role in pharmacokinetic processes such as absorption, distribution and elimination. The potential modulation of their transport function by natural compounds commonly present in plant food or food supplements may result in the changes of the concentration of their substrate (drug) in the cells and body fluids, that may affect the effect and toxicity of these drugs. The aim of this study was to obtain data on the interactions of selected natural compounds with human transporters OATP2B1 and OATP1A2 and their ability to affect drug transport mediated by these transporters. These two OATP transporters are involved in the drug uptake especially in organ barriers important for pharmacokinetics. For the study natural compounds from the group of...
|
|
|
Tissue and soluble endoglin relation to the endothelial dysfunction and possible treatment
Blažíčková, Kateřina ; Nachtigal, Petr (advisor) ; Blaha, Vladimír (referee) ; Mičuda, Stanislav (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Sciences Candidate: Msc. Katerina Blazickova Supervisor: Assoc. Prof. PharmDr. Petr Nachtigal, Ph.D. Title of Doctoral Thesis: Tissue and soluble endoglin relation to the endothelial dysfunction and possible treatment Atherosclerosis is a complex inflammatory disease and it represents a major source of morbidity and mortality in the world as a part of cardiovascular diseases. Endothelial dysfunction represents the first step in the development of atherosclerosis and it is characterized by disruption of endothelial homeostasis. Statins are drugs of choice in the treatment of atherosclerosis and they can decrease LDL cholesterol levels and positively affect levels of HDL cholesterol. Statins, however have a wide range of other effects, which are referred to non-lipid or pleotropic effects. The most important non-lipid effects of statins are lipid- independent modulation of endothelial function, antioxidant, anti-inflammatory, antithrombogenic and antiproliferative effects. The most widely used animal model for the study of atherosclerosis is the mouse model. Thanks to a high fat diet and genetic modification, we are able to modify lipid profile in mice and induce atherosclerotic changes even at...
|
|
|
Immunohistochemical analysis of SMAD proteins expression in experimental atherogenesis.
Lasotová, Magdalena ; Nachtigal, Petr (advisor) ; Mičuda, Stanislav (referee)
Magdalena Lasotová Immunohistochemical analysis of expression of SMAD proteins in experimental atherogenesis. Diploma thesis Charles University in Prague, Faculty of Pharmacy in Hradec Králové Pharmacy Background: We observed the effect of atorvastatin on the expression of phosphorylated form of SMAD 3 in atherosclerotic plaques of ApoE / LDL recep- tor deficient mice. Methods: We used C57BL/6J female mice with double deficiency of apolipopro- tein E and LDL receptor. Animals were divided into two groups. For 8 weeks bo- th groups were fed a standard diet. Animals of the second group received addi- tion of atorvastatin 50 mg/1 kg/day. Blood samples were taken for biochemical analysis. Histological staining with oil red we have taken for the determination of lipids in atherosclerotic lesions. For immunohistochemical analysis were used samples containing semilunar valves with aorta. Detection of expression of SMAD 3 protein was performed using Avidin-Biotin method (ABC) with detecti- on using DAB. Results: Administration of atorvastatin significantly increased level of total cho- lesterol and VLDL cholesterol. Despite hypercholesterolemic effect the adminis- tration of atorvastatin resulted in significant reductions of atherosclerotic lesi- ons compared with the control group. Immunohistochemical...
|
|
|
Interactions of cyclin-dependent kinase inhibitors with ABC efflux transporters in vitro: impact on multidrug resistance in cancer therapy
Číhalová, Daniela ; Štaud, František (advisor) ; Kollár, Peter (referee) ; Mičuda, Stanislav (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Mgr. Daniela Číhalová Supervisor: Prof. PharmDr. František Štaud, PhD. Consultant: PharmDr. Martina Čečková, PhD. Title of doctoral thesis: Interactions of cyclin-dependent kinase inhibitors with ABC efflux transporters in vitro: impact on multidrug resistance in cancer therapy Cyclin-dependent kinases play an important role in cell cycle regulation and their enhanced activity can lead to the development of various malignancies. Therefore, these kinases have become a rational target for inhibition in cancer therapy and many compounds from the group of cyclin-dependent kinase inhibitors (CDKIs) are being evaluated in clinical trials. ABC efflux transporters are expressed in physiological tissues, where they influence the absorption, distribution and elimination of their substrates including drugs and determine their pharmacokinetic properties. On the other hand, overexpression of ABC transporters in cancer cells can contribute to the development of multidrug resistance (MDR) against structurally and functionally diverse compounds. Three members of the ABC transporter family play the most prominent role in the development of MDR: ABCB1 (P-glycoprotein), ABCG2 (breast cancer...
|
|
|
Novel approaches for development of in vitro liver cell models
Smutný, Tomáš ; Pávek, Petr (advisor) ; Mičuda, Stanislav (referee) ; Kollár, Peter (referee)
1 Abstract Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Tomáš Smutný, MSc. Supervisor: Prof. PharmDr. Petr Pávek, Ph.D. Title of doctoral thesis: Novel approaches for development of in vitro liver cell models. The liver is a main metabolizing organ in the body. Therefore, the evaluation of hepatic metabolism is a crucial step during drug development. Moreover, a liver damage induced by drugs is another task to be assessed in drug development. In vitro liver cell models allow addressing some of these concerns. Up to date, primary human hepatocytes are considered as a "gold" standard of in vitro liver cell models. Additionally, other liver model systems are used such as liver tissue slices, subcellular fractions, liver cancer cell lines and hepatocytes derived from stem cells. Despite the significant progress towards right estimation of pharmacokinetic and toxicological parameters of drug candidates during drug development, current in vitro systems still suffer from various drawbacks. One of these limitations is their insufficient similarity with in vivo-like phenotype associated with low metabolic capacity of the models. In last several years, we were victims of tremendous effort to improve existing models such as 3D models, co-culture and...
|
|
|
Spirulina platensis effects on atherogenesis in mouse model of atherosclerosis.
Hanusová, Kateřina ; Nachtigal, Petr (advisor) ; Mičuda, Stanislav (referee)
Spirulina platensis is a single cell blue-green algae of Cyanobacteria strain. Spirulina belongs among foodstuffs with the highest protein content and contains all essential amino-acids. It is also a source of some non essential amino-acids, important nutrients as for example gamma linol acid, a lot of vitamins (B1, B2, B6, biotin, etc.) and trace elements (e.g. selenium, chrome, iron, calcium). Moreover it contains natural pigments carotenoids, chlorophyll and phycocyanin. The aim of this thesis was to test potential hypolipidemic and anti- inflammatory effects of Spirulina platensis on an experimental animal model of apoE/LDLr deficient mice. Therefore the parameters of lipid spectrum in blood and VCAM-1 expressions in arterial endothelium were monitored. Mice with deficit of apolipoprotein E (apoE-/- ) and LDL receptor were weaned of and for two weeks fed with a standard diet. At the age of eight weeks they started to be fed with atherogenic diet containing 0.15% of cholesterol. This continued for eight weeks (control group). In Spirulina platensis group the mice were fed with the same atherogenic diet with daily addition of 20 mg of Spirulina platensis. Biochemical analysis of lipid spectrum as well as histochemical and imunohistochemical analyses of atherosclerotic plates and VCAM-1...
|
|
|
Alterations in gene expression of hepatobiliary transporters as potential mechanisms for drug-induced cholestasis by amoxicillin and clavulanic acid
Řepová, Veronika ; Pávek, Petr (advisor) ; Mičuda, Stanislav (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Veronika Řepová Supervisor: Prof. PharmDr. Petr Pávek, Ph.D., Prof. Ramiro Jover Atienza, Ph.D. Title of diploma thesis: Alterations in gene expression of hepatobiliary transporters as potential mechanisms for drug-induced cholestasis by amoxicillin and clavulanic acid The combination of amoxicillin and clavulanic acid (AMO/CLA) represents one of the most frequent causes of the idiosyncratic type of drug-induced liver injury (DILI) nowadays. Despite difficulties in diagnosis and causality assessment, the clinical features have already been reported and in most of the cases categorized as cholestatic damages. Number of descriptions of the molecular mechanisms of drug-induced cholestasis has been rising recently and the role of hepatobiliary transporters has turned out to be crucial in the pathogenesis. However, the mechanisms of AMO/CLA-induced DILI at the molecular level still remain indistinct. In order to investigate the hepatotoxic effects of AMO/CLA and AMO alone in vitro, HepG2 and human Upcyte hepatocytes were used as hepatocellular models. The mRNA levels of key bile acid (BA) transporters, enzymes and nuclear receptors (NRs) were measured by quantitative real-time polymerase chain...
|
guest ::
