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The role of nitric oxide in cardioprotection induced by chronic hypoxia
Mandíková, Petra ; Neckář, Jan (advisor) ; Szárszoi, Ondrej (referee)
The aim of present project was to uncover the effect of pharmacological increase in acute and chronic nitric oxide (NO) production on cardioprotective effect of chronic hypoxia. We studied the effect of NO donor molsidomine on hemodynamic conditions and ischemia - induced myocardium injury. Male Wistar rats were exposed to continual hypoxia in a normobaric chamber (10 % O2, 4 weeks). Rats received molsidomine either chronically (15 mg/kg/day) in drinking water or acutely (10 mg/kg) in saline infused 30 min before ischemia. Control rats were kept under normoxia and treated in a corresponding manner. Adaptation to chronic hypoxia resulted in development of pulmonary hypertension. Chronic treatment with molsidomine slightly reduced these consequences of chronic hypoxia but it had no effect on increased cardiac ischemic tolerance in chronically hypoxic rats. On the other hand acute treatment with molsidomine significantly reduced infarct size and increased the number of arrhythmias in both normoxic and chronically hypoxic animals. In conclusion, our data suggests that acute increase in availability of NO is cardioprotective in both normoxic and chronically hypoxic rats contrary to its chronic increase which seems to have no protective contribution.
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The role of the endothelin system in development of hypertension and hypertensive end-organ damage in Ren-2 transgenic rats
Opočenský, Martin ; Červenka, Luděk (advisor) ; Neckář, Jan (referee) ; Widimský, Jiří (referee)
The role of the endothelin system in development of hypertension and hypertensive end- organ damage in Ren-2 transgenic rats Endothelin-I (ET-I) has been described as one ofthe most powerful vasoconstrictors, that also play a role in the regulation of renal hemodynamics. ET system plays an important role in the pathogenesis of salt-sensitive models of hl'pertension. The benefícial effects of ET receptor blockers in modulating target-organ damage arise rrom their antiproliferative action. There is, however, a large discrepancy in the effect of ET between various models of hypertension. The hypertensive rat strain transgenic for the mouse Ren-2 (TGR) renin gene is a valuable monogenetic model of renin-dependent and thus angiotensin lI(Ang ll) - dependent hypertension, which exhibits typical signs of fulminant hypertension,i.e. reduced glomerular fíltration rate and proteinuria associated with g1omerulosderosis. Moreover, it carries a salt- sensitive component. We have recently found that nonselective endothelin ETA/ETB receptor blockade markedly improves survival rate and ameliorates end'-organ damage in malcTGR without lowering blood pressure. Because activation ofthe ETA receptor may be responsible for the detrimental effects of ET in the development of hypertension, our study was performed to...
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Segmentace trhu
Neckař, Jan ; Hebák, Petr (advisor) ; Staněk, Miloš (referee)
Hlavním cílem mé práce bylo užití vícerozměrných statistických analýz v praktickém využití. Vybral jsem si segmentaci trhu. Vytvořil jsem několik skupin lidí, podle toho jaký mají vztah k reklamě. Uživatel této analýzy tak může zaměřit své úsilí pouze na část populace, kde bude reklama účinná.
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