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The role of endothelin receptors type A and B in the model of focal cerebral ischemia in immature rats
Vondráková, Kateřina ; Tsenov, Grygoriy (advisor) ; Říčný, Jan (referee)
Hypoxic-ischemic insult is a most common form of perinatal brain damage that threatens a newborn's life and can leads to permanent neurological sequelae. However, detailed aspects of the cerebral ischemia in the immature brain stay unanswered. We decide to use the model of focal cerebral ischemia induced by intrahippocampal endothelin-1 (ET-1) in 12-days-old rats. The knowledge about consequences of ET-1 induced ischemia and the role of endothelin receptors (ETA and ETB) in ischemia-induced consequences in immature brain are poor at present. Agonists and selective antagonists of the ETA and ETB receptors were used to determine the role of these receptors in the development of ischemia, changes in regional blood flow and tissue oxygenation, local changes of biochemical parameters and acute neuronal death. Our results indicates, that activation of the ETA receptors causes a strong decrease of the blood flow, induced related hypoxia and subsequent neuronal degeneration, whereas activation of ETB receptors has likely modulatory role. Moreover, ischemia causes increase of excitatory amino acids concentration, whereas inhibitory amino acid, except taurine, decreased after ischemia. These facts provides new insights in a case of perinatal ischemia. This thesis demonstrates the wide range of different effects of...
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Acipimox during Short-Term Exercise Exerts A Negative Feedback of Growth Hormone on Ghrelin Secretion in Patients with Bulimia Nervosa and in Healthy Women: The Role of Lipolysis
Smitka, Kvido ; Nedvídková, Jara (advisor) ; Kršek, Michal (referee) ; Čáp, Jan (referee)
Title: Acipimox during Short-Term Exercise Exerts A Negative Feedback of Growth Hormone on Ghrelin Secretion in Patients with Bulimia Nervosa and in Healthy Women: The Role of Lipolysis Objective: Eating disorders, such as bulimia nervosa (BN) and anorexia nervosa (AN), are characterized by abnormal eating behavior. The main features of BN are binge-eating and inappropriate compensatory methods to prevent weight gain. The appetite-modulating peptide ghrelin is secreted by the stomach and shows a strong release of growth hormone (GH). A potential GH-ghrelin feedback loop between stomach and the pituitary has been recently reported. Acipimox (Aci), an analogue of nicotinic acid, inhibits lipolysis in adipose tissue (AT) and reduces plasma glycerol and free fatty acids (FFA) levels. Exercise and Aci are stimulators of GH secretion. We suppose that a negative feedback from increased GH levels during exercise may play a role in reducing plasma ghrelin levels. We surmised that altered baseline activity and exercise-induced activation of the sympathetic nervous system (SNS) results in excessive stimulation of lipolysis associated with negative energy balance and may lead to abnormal AT metabolism in patients with BN. Disruption of the gut-brain-AT axis might be involved in the pathogenesis of BN. The...
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The role of endothelin receptors type A and B in the model of focal cerebral ischemia in immature rats
Vondráková, Kateřina ; Tsenov, Grygoriy (advisor) ; Říčný, Jan (referee)
Hypoxic-ischemic insult is a most common form of perinatal brain damage that threatens a newborn's life and can leads to permanent neurological sequelae. However, detailed aspects of the cerebral ischemia in the immature brain stay unanswered. We decide to use the model of focal cerebral ischemia induced by intrahippocampal endothelin-1 (ET-1) in 12-days-old rats. The knowledge about consequences of ET-1 induced ischemia and the role of endothelin receptors (ETA and ETB) in ischemia-induced consequences in immature brain are poor at present. Agonists and selective antagonists of the ETA and ETB receptors were used to determine the role of these receptors in the development of ischemia, changes in regional blood flow and tissue oxygenation, local changes of biochemical parameters and acute neuronal death. Our results indicates, that activation of the ETA receptors causes a strong decrease of the blood flow, induced related hypoxia and subsequent neuronal degeneration, whereas activation of ETB receptors has likely modulatory role. Moreover, ischemia causes increase of excitatory amino acids concentration, whereas inhibitory amino acid, except taurine, decreased after ischemia. These facts provides new insights in a case of perinatal ischemia. This thesis demonstrates the wide range of different effects of...
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Acipimox during Short-Term Exercise Exerts A Negative Feedback of Growth Hormone on Ghrelin Secretion in Patients with Bulimia Nervosa and in Healthy Women: The Role of Lipolysis
Smitka, Kvido ; Nedvídková, Jara (advisor) ; Kršek, Michal (referee) ; Čáp, Jan (referee)
Title: Acipimox during Short-Term Exercise Exerts A Negative Feedback of Growth Hormone on Ghrelin Secretion in Patients with Bulimia Nervosa and in Healthy Women: The Role of Lipolysis Objective: Eating disorders, such as bulimia nervosa (BN) and anorexia nervosa (AN), are characterized by abnormal eating behavior. The main features of BN are binge-eating and inappropriate compensatory methods to prevent weight gain. The appetite-modulating peptide ghrelin is secreted by the stomach and shows a strong release of growth hormone (GH). A potential GH-ghrelin feedback loop between stomach and the pituitary has been recently reported. Acipimox (Aci), an analogue of nicotinic acid, inhibits lipolysis in adipose tissue (AT) and reduces plasma glycerol and free fatty acids (FFA) levels. Exercise and Aci are stimulators of GH secretion. We suppose that a negative feedback from increased GH levels during exercise may play a role in reducing plasma ghrelin levels. We surmised that altered baseline activity and exercise-induced activation of the sympathetic nervous system (SNS) results in excessive stimulation of lipolysis associated with negative energy balance and may lead to abnormal AT metabolism in patients with BN. Disruption of the gut-brain-AT axis might be involved in the pathogenesis of BN. The...
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High-fast electrophoretic determinations of clinically important compounds in body fluids.
Málková, Klára ; Kvasnicová, Vladimíra (referee) ; Bosáková, Zuzana (advisor)
A capillary electrophoretic procedure employing contactless conductivity detection (C4 D) has been developed for direct determination of the glycerol and mannitol polyalcohols in biological and pharmacological samples. Both glycerol and mannitol are fully separated from the sample matrix within very short times of 3.0 and 3.9 min., respectively, when using the optimized background electrolyte, 60 mM H3BO3 + 30 mM LiOH (pH 9.1). The limits of detection amount to 0.5 µM for glycerol and 0.3 µM for mannitol. The repeatability of the glycerol determination in real biological materials is characterized by the coefficient of variation values, 0.5 % and 3.2 %, for the migration time and the peak area, respectively. The procedure has been used to monitor the free glycerol concentration in adipose tissue microdialyzates. A physiological study has demonstrated that the lipolysis occurring during a sporting action can be stimulated by local application of adrenaline. The procedure has further been utilized to determine mannitol in a pharmacological preparation.
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