This diploma thesis deals with analysis of electrograms recorded from isolated rat hearts. In theoretical part, basic principles of electrocardiography and differences between rat and human EG records are described. Types of arrhythmias and methods for classification and quantification of arrhythmias are also described. Examples of pathologies found during the manual classification and results of the analysis of the QTc interval duration are presented. An occurrence of premature beats is then compared between experimental groups. Finally, the method used for the automatic analysis of electrograms including the graphical user interface is described and the results of its evaluation using real data are presented

Acute cold exposure is a significant stressor activating heat production by shivering after the prolonged exposure cellular oxidative stress increases. Chronic exposure to cold lasting at least 2 weeks leads to the development of cold acclimatization. The main thermogenic role is taken over by non-shivering thermogenesis taking place in brown adipose tissue, which significantly increases its weight due to cold. Cardiac hypertrophy, hypertension and impaired renal function are frequently observed pathologies of acclimatization at 4-5 řC. Our laboratory recently introduced a model of mild chronic cold acclimatization at 8 řC, during which no damage to the heart or kidneys occurs and has proven cardioprotective effect on reducing infarct size. Hence, the influence of this cold acclimatization model on the other cellular and molecular processes needs to be investigated. The cardioprotective effect of cold acclimatization includes changes in β-AR signaling, activation of anti-apoptotic pathways or augmentation of the antioxidant system. The aim of this thesis was to investigate the effect of cold acclimation and subsequent reacclimation on proteins regulating Ca2+ levels in the rat heart (SERCA2 and phospholamban) and on the stimulation of regulatory proteins β-arrestin 1/2 and protein kinase PDPK1. The...

Cold exposure elicits a thermoregulatory response in an organism. If the cold stimulus is sufficient, there is increased heat generation by shivering thermogenesis. Under prolonged action of the cold stimulus, shivering thermogenesis is replaced by non-shivering thermogenesis. Non-shivering thermogenesis in the rat takes place predominantly in brown adipose tissue (BAT), where the uncoupling protein 1 (UCP1) is activated in mitochondria under the control of adrenergic signaling. The activity of UCP1 is crucial for heat production. The coactivator PGC-1α plays an important role in mitochondrial biogenesis and in the energy metabolism of BAT and heart, and its function is associated with cardioprotection. Recently, the cardioprotective effects of mild cold adaptation at 8±1 řC were discovered in our laboratory, which reduced the size of ischemia-reperfusion injury without negative side effects. However, the molecular nature of the events induced by adaptation to mild cold is unknown neither in BAT nor in the heart itself. Therefore, the aims of the thesis were 1) to characterize the development of BAT at the level of expression of selected proteins and mitochondrial markers during acute cold exposure and chronic cold adaptation with subsequent recovery and 2) to determine the role of PGC-1α and...

Opioids are considered as a dangerous addictive substances which are widely used in medicine for their strong analgetic effects. Opioids (such as morphine and methadon) may nevertheless play an important role in the resistance of the heart to ischemia by reducing the rate of cell damage. This protective effect is well understood about morphine but we don't know almost nothing about effects of methadone on the myocardium. The main aim of this thesis was to find out how chronic methadone treatment affects ischemic tolerance of rat hearts. For our experiments we used Wistar rats in two series. In the first series we administered morphine (10 mg/kg/day, i.m.) or methadone (2 mg/kg/day, i.m.) for 10 days. In the second experiment series we administered methadon for 28 days (2 mg/kg/day, i.m.). For analysis of the ischemic heart tolerance we used the isolated perfused heart method. Incidence and severity of ischemia and reperfusion arrhythmias were analyzed during the 50 min of ischemia and early reperfusion. Infarct size was analyzed histochemically, using tetrazolium salts and KMnO4 1 h after reperfusion and was determined by planimetric method. In the first series of experiments analyzing the effect of 10-day administration of both opioids on the resistance of the heart to ischemia we did not find a...

The thesis is focused on the intra-aortic balloon counterpulsation (IABP) from the perspective of nurses in the cardiac intensive care. It consists of two parts. Theoretical and empirical. The theoretical part will deal with the intra-aortic balloon counterpulsation, including basic anatomy of the heart and blood vessels, the principle of IABC, its indications, contraindications, technology IABC and specific nursing care of patients with established IABC. The empirical part is treated as quantitative research, which is used for the data collection method anonymous questionnaire. The aim of the thesis is to determine nurses' knowledge of IABC in the cardiac intensive care and subsequent drafting of guidance for postoperative cardiac surgery department KARIM University, Prague. In this section are also included important questions and answers from the perspective of the specified variables obtained from the questionnaire and subsequent actions arising in practice. Key words Counterpulsation, Cardiac cycle, Aorta, Heart, Nursing care

Cold adaptation and her effects has been known for many decates. Positive or negative impact depends especially on its length and strength. The lower temperature can very often cause the stress for organism. On the other hand in expreriment with long-term adapatation were found positive consequences on cardiovascular system. We found the lack of studies devoted to the energy metabolism and apoptosis in heart tissue during long-term cold adaptation. In this work we used a model with milder conditions of the adaptation (10žC±1), so there wouldn't be damage of the experimental animals. We compared the resuls betwen control, cold and regressive group of rats. In this expreriment we used methods of electrophoresis and Western blot. The target of the work was found if we can find any differences betwen chosen HIF targeted genes. The next goal was to detect the differences betwen chosen pro-apoptotic and anti-apoptotic markers. Keywords: cold adaptation, heart, energetic metabolism, HIF, apoptosis

Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in Europe. Over 4 million people die from CVDs annually and another 11 million people develops CVDs every year. These numbers show that there is a need for better diagnostic, prognostic and predictive biomarkers and, more importantly, a need for new and more efficient drugs. Integral membrane proteins (IMPs) are ideal candidates for new drug targets. However, a study of IMPs represents a major challenge in current proteomics. This challenge is associated with the low abundance of IMPs, their low solubility in aqueous solvents and the absence of trypsin cleavage sites in their transmembrane segments. To overcome these issues, methods that selectively target either N-glycosylated extra-membrane segments (CSC, SPEG, N-glyco-FASP) or transmembrane segments (hpTC) were developed. In this thesis we employed a combination of two N-glyco-capture methods (SPEG and N-glyco-FASP) performed on two different samples (membrane-enriched fraction and total tissue lysate) with analysis of membrane-embedded IMP segments by hpTC and with standard non-targeted "detergent+trypsin" approach to analyze rat myocardial membrane proteome. We also performed an evaluation of employed methods for preparation of membrane fraction by western blot...

During cold acclimation the heat production is shifted from shivering to non-shivering thermogenesis, which is mediated by adrenergic signaling. It has also been observed, that cold acclimation may increase the organismal resistence to pathological stimuli and may affect functional parameters of cardiovascular system. However, acute exposure to sever cold is often associated with detrimental effects on the body. We have recently shown that chronic exposure to cold increases the heart's resistance to ischemia-reperfusion injury without negative side effects when mild temperatures are used, however the mechanism of protection is not yet known. The aim of this work was to determine whether: i) if the sensitivity of the heart to ischemia changes already after the first day of cold exposure and does not show any negative effects, ii) if β1-adrenergic signaling plays a role in chronic regimen of cold-induced cardioprotection. The results of this work showed that i) one day of exposure to mild cold did not change the sensitivity of the heart to ischemia and ii) metoprolol treatment reduced the infarct size in the control group, but did not affect the heart of cold-adapted rats. Key words : Heart, rat, beta 1 adrenergic receptors, cold acclimation

Cardiovascular diseases account for the majority of deaths both worldwide and in the Czech Republic. Main factors contributing heart disease development, aside age and sex, are obesity, high blood pressure and high blood cholesterol and triglyceride levels. Spontaneously hypertensive rat (SHR) was developed and used for search of genetic determinants of these traits. This commonly used rat model develops hypertension, dyslipidemia, and insulin resistance naturally which is caused by aberrant Cd36 fatty acid translocase gene. Previous studies have shown that rescue of Cd36 performed in the transgenic SHR-Tg19 strain enhances cardiac beta-adrenergic system, slightly increases heart mass and leads to higher susceptibility to arrhythmias. The present thesis had two main aims: 1) To investigate whether and how a transgenic rescue of Cd36 in SHR affects protein composition, mitochondrial function and activity of selected metabolic enzymes of the heart. 2) To study the expression and distribution of selected components of beta-adrenergic signaling system in lipid raft isolated form membranes using the TX-100 detergent. We set to compare two commonly used proteomic approaches, 2D electrophoresis with MALDI-TOF mass spectrometry and label-free LC-MS. The results did not reveal any overlap between...

Ventricular arrhythmias are the main cause of death worldwide. An increased incidence of arrhythmias in the heart of mammals is accompanied by a remodeling of the cellular distribution gap between the channels of mainly connexin 43 (Cx43). Recently has been demonstrated significant effect of mitochondria and their association with arrhythmogenesis. Various pathological conditions alter the expression and / or distribution of Cx43, depending on the phosphorylation status. but also on altering the association of hexokinase with mitochondria, which reduces the likelihood of apoptosis activation. Adaptation to intermittent hypobaric hypoxia potentiates endogenous pathways reducing the incidence of ventricular arteries, whereas continuous normobaric hypoxia does not have this effect. Another studied model is cold acclimatization, which has been known for several decades by known effects on human health. However, the heart study of these models in relation to Cx43 is missing. Our goal was to determine the expression of Cx43, phosphorylated Cx43 (p-Cx43) and hexokinase (HK1, HK2) and their distribution in cardiomyocytes. In addition, the expression of Cx43 upstream kinases, protein kinase A, protein kinase G, casein kinase 1 in normoxic and hypoxic left ventricles of rats, along with Cx43 distribution...