|
|
Endothelin system and the role of salt in hypertension
Čejková, Soňa ; Vaněčková, Ivana (advisor) ; Soták, Matúš (referee)
Although hypertension is studied for several decades, this problem is still not solved. Moreover, its incidence increases. Most cases of secondary hypertension is associated with the kidneys, the most important organ regulating the volume and ionic composition of body fluids. If the kidneys are damaged, or intake of salt is excessive, they are unable to fulfill their role and blood pressure (BP) increases. Especially salt contributes to secondary hypertension. Excessive salt intake increases the volume of body fluids and subsequently increases BP, and secondary act on the mechanisms regulating BP, mainly the renin-angiotensin system (RAS) and endotelin (ET) system. Endothelin-1 (ET 1) is the main active peptide of the ET system. ET-1 is one of the most potent vasoconstrictors. It acts through ET receptors type A and B (ETA and ETB receptors), which belong to the family of receptors coupled with G-proteins. The effects of ETA and ETB receptors differ depending on the type of cells where they are located. For example, ETB receptors in vascular smooth muscle contribute to vasoconstriction, whereas the same receptors on endothelial cells of blood vessels mediate vasodilation (stimulating the production of NO). In the kidney, ET system affects excretion of Na+and water and contribute to the regulation...
|
|
|
Aldosterone synthase in arterial hypertension and possible influence of its genenetic polymorphism on left ventricular hypertrophy
Heller, Samuel ; Horký, Karel (advisor) ; Málková, Jana (referee) ; Widimský, Jiří (referee)
Part I. The aldosterone synthase gene (CYP11B2) polymorphism T-344C in blood pressure and left ventricular hypertrophy. BACKGROUND: Aldosterone is a key cardovascular hormone, it significantly influences volume, pressure and electrolyte balance. Aldosterone plays an important role in development of left ventricular (LV) hypertrophy and myocardial fibrosis. The aldosterone synthase gene (CYP11B2) is an important candidate gene region in essential hypertension. DESIGN AND METHODS: We assessed the influence of the T-344C polymorphism of aldosterone synthase - the rate-limiting enzyme in aldosterone biosynthesis - on the structure of the left ventricle in young normotensive men. The population included 113 normotensive mid-European Caucasian men aged 18-40 years (mean 27 +/- 5 years). We also studied the association of -344T/C polymorphism of the CYP11B2 gene with the presence and severity of hypertension in 369 individuals, of whom 213 were hypertensive patients (139 controlled hypertensive, 74 resistant hypertensive) and 156 were healthy normotensive subjects. The genotype was assessed using polymerase chain reaction with subsequent cleavage with restriction enzyme HAEIII (restriction fragment length polymorphism method) and visualization with ethidium bromide. Plasma renin activity (PRA) and plasma...
|
|
|
Endothelin system and the role of salt in hypertension
Čejková, Soňa ; Vaněčková, Ivana (advisor) ; Soták, Matúš (referee)
Although hypertension is studied for several decades, this problem is still not solved. Moreover, its incidence increases. Most cases of secondary hypertension is associated with the kidneys, the most important organ regulating the volume and ionic composition of body fluids. If the kidneys are damaged, or intake of salt is excessive, they are unable to fulfill their role and blood pressure (BP) increases. Especially salt contributes to secondary hypertension. Excessive salt intake increases the volume of body fluids and subsequently increases BP, and secondary act on the mechanisms regulating BP, mainly the renin-angiotensin system (RAS) and endotelin (ET) system. Endothelin-1 (ET 1) is the main active peptide of the ET system. ET-1 is one of the most potent vasoconstrictors. It acts through ET receptors type A and B (ETA and ETB receptors), which belong to the family of receptors coupled with G-proteins. The effects of ETA and ETB receptors differ depending on the type of cells where they are located. For example, ETB receptors in vascular smooth muscle contribute to vasoconstriction, whereas the same receptors on endothelial cells of blood vessels mediate vasodilation (stimulating the production of NO). In the kidney, ET system affects excretion of Na+and water and contribute to the regulation...
|
guest ::
