Search results for "Renin–angiotensin system"
showing 10 items of 69 documents
Does the renin-angiotensin system also regulate intra-ocular pressure?
2009
The renin-angiotensin-aldosterone system is known to play an essential role in controlling sodium balance and body fluid volumes, and thus blood pressure. In addition to the circulating system which regulates urgent cardiovascular responses, a tissue-localized renin-angiotensin system (RAS) regulates long-term changes in various organs. Many recognized RAS components have also been identified in the human eye. The highly vasoconstrictive angiotensin II (Ang II) is considered the key peptide in the circulatory RAS. However, the ultimate effect of RAS activation at tissue level is more complex, being based not only on the biological activity of Ang II but also on the activities of other produ…
Spectrum of mutations in the renin-angiotensin system genes in autosomal recessive renal tubular dysgenesis
2012
Autosomal recessive renal tubular dysgenesis (RTD) is a severe disorder of renal tubular development characterized by early onset and persistent fetal anuria leading to oligohydramnios and the Potter sequence, associated with skull ossification defects. Early death occurs in most cases from anuria, pulmonary hypoplasia, and refractory arterial hypotension. The disease is linked to mutations in the genes encoding several components of the renin-angiotensin system (RAS): AGT (angiotensinogen), REN (renin), ACE (angiotensin-converting enzyme), and AGTR1 (angiotensin II receptor type 1). Here, we review the series of 54 distinct mutations identified in 48 unrelated families. Most of them are no…
Tagesprofile von Plasmaaldosteron,-Cortisol, -Renin, -Angiotensinogen und -Angiotensinasen bei Normalpersonen
1976
Plasma cortisol and renin were estimated in 1 h intervals, plasma aldosterone, angiotensinogen and angiotensinases in 3 h intervals over periods of 24 h in six normal volunteers (age 20-26) under control conditions and subsequently under suppression of ACTH release by dexamethasone. Highest cortisol levels were found around 7 a.m., minimum levels between 9 p.m. and 1 a.m. Dexamethasone reduced cortisol to constantly low concentrations. Aldosterone was highest around 4 a.m. under control conditions and under dexamethasone, and showed lowest concentrations between 4 and 10 p.m. There were no significant differences between mean aldosterone concentrations at corresponding time points of the co…
Changes of Angiotensin Converting Enzyme (Ace) Levels During Activation of the Renin-Angiotensin-Aldosterone System (RAAs)
1987
The aim of this study was to evaluate the changes of ACE levels during RAAs activation induced by: 1) a continuous graded bicycle ergometer test performed in a group of 15 males health youths aged between 21 and 30 years, with average age of 25.8 +/- 2.85 years; 2) i.m. injection of 20 mg of frusemide in 11 health youths (10 males and 1 female), aged between 20 and 30 years, with average age of 24.09 +/- 2.77 years; 3) dialytic treatment in 25 patients (12 males and 13 females), suffering from chronic renal failure, aged between 26 and 68 years, with average age of 54 +/- 15.42 years. Plasmatic renin activity (PRA), aldosterone (ALD) and ACE levels were determined by RIA in basal conditions…
Conceptos nuevos sobre el sistema renina angiotensina
2010
In recent years, new components of the renin-angiotensin system have been described. Five new polypeptides with their synthesis routes and the enzymes involved in their synthesis have been identified. Receptors for angiotensin 1–7, angiotensin IV and renin have also been described. The knowledge of local renin-angiotensin systems has been extended with the discovery of the intracellular systems. Mutations and polymorphisms in the genes of the different components of the renin-angiotensin system have been described. These could be involved in the development of hypertension and cardiovascular disease. In addition, aliskiren, the first component of the new group of renin direct inhibitors, ha…
Experiences with Blockade of the Renin System in Human Hypertension Using Converting Enzyme Inhibitor SQ 20,881 and Saralasin
1980
The development of agents which are capable of producing in vivo angiotensin II blockade has provided to investigators and clinicians alike the opportunity to determine and to quantify the extent to which the renin-angiotensin system participates in the maintenance of hypertensive states. High levels of plasma renin activity relative to the state of sodium balance have been documented in patients with malignant, surgically remediable renovascular hypertension and also in some patients with essential hypertension.1 The recent development of the angiotensin II analogue sar1-ala8-angiotensin II (saralasin) provided evidence to support the concept that these elevated renin levels are in fact pa…
Activities of angiotensin-converting enzymes ACE1 and ACE2 and inhibition by bioactive peptides in porcine ocular tissues.
2009
An active local renin-angiotensin system (RAS) has recently been found in the human eye. The aim of the present study was to compare the activities of central RAS enzymes (ACE1 and 2) in porcine ocular tissues, morphologically and physiologically close to the human eye. In addition, the effects of three ACE-inhibitory tripeptides on these enzymes were evaluated.Enucleated fresh porcine eyes were used. Activities of ACE1 and ACE2 and their inhibition by bioactive tripeptides (Ile-Pro-Pro, Val-Pro-Pro, Leu-Pro-Pro) as well as by a standard ACE-inhibitor captopril were assayed in the vitreous body, the retina and the ciliary body using fluorometric detection methods.Activity of ACE1 as well as…
Alcohol puts the heart under pressure: Acetaldehyde activates a localized renin angiotensin aldosterone system within the myocardium in alcoholic car…
2018
Angiotensin II-Stoffwechsel bei Angiotensininfusion und bei Kochsalzentzug
1975
1. Bei funf normotonen Probanden wurde im arteriellen und venosen Plasma des Unterarms vor und nach diatetischem Salzentzug sowie vor und wahrend Infusion von Angiotensin II-amid Angiotensin II (A II) und der Angiotensinmetabolit Angiotensin (3–8)-Hexapeptid (H) nach dunnschichtchromatographischer Trennung radioimmunologisch bestimmt.