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The enzymes of catecholamine metabolism in experimental hypertension.
Loučková, Anna ; Kuneš, Jaroslav (advisor) ; Klevstigová, Martina (referee)
Catecholamines dopamine, norepinephrine and epinephrine are significantly involved in regulation of blood pressure. The most important enzymes participating in their metabolism are tyrosin hydroxylase, DOPA dekarboxylase, dopamine β-hydroxylase and phenylethanolamine N-methyltransferase. This thesis summarizes current knowledge about these enzymes, focusing on their role in the development of essential hypertension. Experimental models are often used in the study of hypertension because of their practical and ethic reasons. Most findings were obtained in spontaneously hypertensive rats, due to their similarity to human essential hypertension. Metabolism of catecholamines in spontaneously hypertensive rat differs in many aspects from that of normotensive controls. The primary cause of this type of hypertension has not yet been distinguished from compensatory responses. However, prevention or slow-down the disease-development process can be achieved by various interventions. This information may help to identify new treatments for human hypertension.
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The role of adrenergic system in genetic hypertension
Loučková, Anna ; Kadlecová, Michaela (advisor) ; Husková, Zuzana (referee)
The adrenergic system plays an important role in the regulation of blood pressure. In the spontaneously hypertensive rat, the most studied model of essential hypertension, many components of the adrenergic system are altered. Changes in expression level of any catecholamine biosynthetic enzymes or any adrenergic receptor subtypes could be one of the causes of hypertension development. In this work, the expression of adrenergic system genes was measured in adrenal gland, renal cortex and renal medulla of the spontaneously hypertensive (SHR), Wistar-Kyoto and Brown Norway rats at the age of thirteen weeks. In adrenal gland of SHR, all four catecholamine biosynthetic enzymes (tyrosine hydroxylase, DOPA decarboxylase, dopamine β-hydroxylase and phenylethanolamine-N- methyltransferase) and almost all subtypes of adrenergic receptors (with the exception of Adra1a and Adra1d) were underexpressed. This generally decreased expression in adrenal gland of SHR suggests that at least a part of regulation of adrenergic system gene expression is common. The mechanism of this downregulation in SHR could be a negative feedback through adrenergic receptors stimulated by high plasma noradrenaline concentration. In the kidney of SHR, there were no differences in the expression of most of adrenergic receptor subtypes with the...
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Preparation of the 14-3-3 Protein Binding Partners for Structural Studies.
Kopecká, Miroslava ; Obšil, Tomáš (advisor) ; Teisinger, Jan (referee)
Tyrosine hydroxylase belongs to the group of hydroxylases of aromatic acids and catalyzes a key step in the biosynthesis of catecholamine neurotransmitters. The tyrosine hydroxylase possesses the homotetrameric structure and contains three structural domains: the N-terminal regulatory domain, the catalytic domain and the C-terminal tetramerization domain. The activity of tyrosine hydroxylase is regulated by phosphorylation and through the regulation of its expression. Phosphorylation at Ser-19 induces binding of the 14-3-3 protein, which affects the structure of the regulatory domain and protects it against both dephosphorylation and degradation. Since the structure of the regulatory domain is still unknown, we decided to perform its structural characterization using NMR techniques. First, the expression and purification protocol of the regulatory domain of tyrosine hydroxylase was optimized. The protein was expressed as a His-tag fusion protein and its purification is composed from two steps: the chelating chromatography and the size-exclusion chromatography. The dynamic light scattering and the 1 H nuclear magnetic resonance were used to verify its monodispersity, and hence its suitability for further experiments.
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The role of adrenergic system in genetic hypertension
Loučková, Anna ; Kadlecová, Michaela (advisor) ; Husková, Zuzana (referee)
The adrenergic system plays an important role in the regulation of blood pressure. In the spontaneously hypertensive rat, the most studied model of essential hypertension, many components of the adrenergic system are altered. Changes in expression level of any catecholamine biosynthetic enzymes or any adrenergic receptor subtypes could be one of the causes of hypertension development. In this work, the expression of adrenergic system genes was measured in adrenal gland, renal cortex and renal medulla of the spontaneously hypertensive (SHR), Wistar-Kyoto and Brown Norway rats at the age of thirteen weeks. In adrenal gland of SHR, all four catecholamine biosynthetic enzymes (tyrosine hydroxylase, DOPA decarboxylase, dopamine β-hydroxylase and phenylethanolamine-N- methyltransferase) and almost all subtypes of adrenergic receptors (with the exception of Adra1a and Adra1d) were underexpressed. This generally decreased expression in adrenal gland of SHR suggests that at least a part of regulation of adrenergic system gene expression is common. The mechanism of this downregulation in SHR could be a negative feedback through adrenergic receptors stimulated by high plasma noradrenaline concentration. In the kidney of SHR, there were no differences in the expression of most of adrenergic receptor subtypes with the...
|
|
|
The enzymes of catecholamine metabolism in experimental hypertension.
Loučková, Anna ; Kuneš, Jaroslav (advisor) ; Klevstigová, Martina (referee)
Catecholamines dopamine, norepinephrine and epinephrine are significantly involved in regulation of blood pressure. The most important enzymes participating in their metabolism are tyrosin hydroxylase, DOPA dekarboxylase, dopamine β-hydroxylase and phenylethanolamine N-methyltransferase. This thesis summarizes current knowledge about these enzymes, focusing on their role in the development of essential hypertension. Experimental models are often used in the study of hypertension because of their practical and ethic reasons. Most findings were obtained in spontaneously hypertensive rats, due to their similarity to human essential hypertension. Metabolism of catecholamines in spontaneously hypertensive rat differs in many aspects from that of normotensive controls. The primary cause of this type of hypertension has not yet been distinguished from compensatory responses. However, prevention or slow-down the disease-development process can be achieved by various interventions. This information may help to identify new treatments for human hypertension.
|
|
|
Preparation of the 14-3-3 Protein Binding Partners for Structural Studies.
Kopecká, Miroslava ; Obšil, Tomáš (advisor) ; Teisinger, Jan (referee)
Tyrosine hydroxylase belongs to the group of hydroxylases of aromatic acids and catalyzes a key step in the biosynthesis of catecholamine neurotransmitters. The tyrosine hydroxylase possesses the homotetrameric structure and contains three structural domains: the N-terminal regulatory domain, the catalytic domain and the C-terminal tetramerization domain. The activity of tyrosine hydroxylase is regulated by phosphorylation and through the regulation of its expression. Phosphorylation at Ser-19 induces binding of the 14-3-3 protein, which affects the structure of the regulatory domain and protects it against both dephosphorylation and degradation. Since the structure of the regulatory domain is still unknown, we decided to perform its structural characterization using NMR techniques. First, the expression and purification protocol of the regulatory domain of tyrosine hydroxylase was optimized. The protein was expressed as a His-tag fusion protein and its purification is composed from two steps: the chelating chromatography and the size-exclusion chromatography. The dynamic light scattering and the 1 H nuclear magnetic resonance were used to verify its monodispersity, and hence its suitability for further experiments.
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