Search results for "renin-angiotensin system"
showing 10 items of 41 documents
Salt-regulating hormones in young normotensive obese subjects. Effects of saline load.
1994
To investigate whether the response of salt-regulating hormones to volume expansion is impaired in obese subjects, we assessed the effects of saline load (0.25 mL/kg.min.120 min) in 9 young, healthy, normotensive obese subjects (body mass index, > 30 kg/m2) and in 10 lean control subjects (body mass index, < 25 kg/m2) matched for age, gender, height, and mean blood pressure. Hematocrit, plasma renin activity (PRA), plasma aldosterone (PA), atrial natriuretic factor (ANF), and urinary sodium excretion (UNaV) were evaluated. Saline load increased ANF levels significantly (P < .001) in lean subjects at both 60 and 120 minutes, whereas they decreased in obese subjects. Such decreases b…
Inefficient arterial hypertension control in patients with metabolic syndrome and its link to renin-angiotensin-aldosterone system polymorphisms.
2011
There is evidence that uncontrolled arterial hypertension (AHT) in patients with metabolic syndrome (MS) increases cardiovascular risks. The renin-angiotensin-aldosterone system (RAAS) and its polymorphisms apparently confer a genetic risk for uncontrolled AHT. This study aims to investigate the influence of RAAS polymorphisms on AHT control in patients diagnosed with MS. This is a two-stage population-based nested case-control pilot study (n=1514). We differentiated between MS-diagnosed patients and non-MS patients (ATP-III criteria) and selected those individuals diagnosed with AHT from each group (n=161 and n=156, respectively). Those who successfully controlled their AHT (controls) and …
Screening for congenital renovascular hypoplasia and renal artery stenosis by acute converting enzyme inhibition.
1993
To evaluate the usefulness of the captopril test for identifying renal artery stenosis (RAS) and renovascular hypoplasia (RAH), we studied 48 hypertensive patients. In 20 hypertensives with screening procedures indicating renovascular disease and in 28 essential hypertensives (EH), the plasma renin activity (PRA) responses to an oral test dose of captopril (50 mg) were studied. A 60-min post-captopril PRA increase of 150% (or 400% if baseline PRA < or = 3 ng/ml/h) was considered as positive. Renal angiography was performed in all cases. Among the 20 renovascular hypertensive patients, RAH in 9 and RAS in 11 subjects were proved by angiography. The captopril test in all patients with RAH res…
Insulin, renin-aldosterone system and blood pressure in obese people.
2001
OBJECTIVE: To evaluate the relationship between insulin, the renin-aldosterone system and blood pressure in obese subjects. DESIGN AND METHODS: A cross sectional study of a group of severely obese normotensive subjects who were surgical candidates (n=39; mean BMI: 47.8±1.4) and a group of hypertensive patients (n=57; mean BMI: 28.0±0.7) twenty-nine of whom had BMI>27. All subjects were studied after 15 days on a balanced diet. Insulin, plasma renin activity and aldosterone were measured. RESULTS: Fasting insulin, plasma renin activity and aldosterone were higher in severely obese normotensive subjects than in hypertensive subjects (respectively 32.3±3.0 vs 13.1±1.0 mU/l, P=0.0001; 1.34±0.22…
Plasma levels of atrial natriuretic peptide and hemodynamic function in cardiac disease.
1993
Plasma concentrations of atrial natriuretic peptide were measured in eight patients with cardiac disease but normal resting right atrial pressure, during cardiac catheterization. No patient had clinical evidence of overt heart failure. An increase in peptide concentrations was observed between the aorta or the peripheral vein and the pulmonary artery. A linear relation was found between peripheral vein and pulmonary artery peptide concentration. Mean pulmonary artery and capillary wedge pressure also correlated with the peptide levels. No correlation was observed between mean right atrial pressure and peptide concentration. These findings demonstrate that atrial natriuretic peptide release,…
Effect of dual blockade of renin–angiotensin system on TGFβ1 and left ventricular structure and function in hypertensive patients
2007
The effects of 24 weeks losartan and ramipril treatment, both alone and in combination, on left ventricular mass (LVM), circulating transforming growth factor beta1 (TGFbeta1), procollagen type I (PIP) and III (PIIIP), have been evaluated in hypertensive (HT) patients. A total of 57 HT with stage 1 and 2 essential hypertension were included. After 4 weeks run in, a randomized double-blind, three arms, double dummy, independent trial was used. All HT patients were randomly allocated to three treatment arms consisting of losartan (50 mg/daily), ramipril (5 mg/ daily) and combined (losartan 50 mg/daily + ramipril 5 mg/daily) for 24 weeks. TGFbeta1, PIP and PIIIP, LVM, LVM/h(2.7) and other echo…
Focus on clinical practice: angiotensin-converting enzyme 2 and corona virus disease 2019: pathophysiology and clinical implications.
2020
: ACE2 receptor has a broad expression pattern in the cellular membrane and provides a protective action against the development of cardiovascular diseases. Recently, this enzyme has become of extreme interest during the pandemic infection of COVID-19 (coronavirus disease 2019). This virus invades alveolar epithelium and cardiomyocytes using ACE2 as a transmembrane receptor. ACE2 is a counter-regulatory peptide that degrades Ang II into Ang 1-7, thereby attenuating the biological effects of the AT1 receptor. The binding between the spike protein of COVID-19 and the enzyme is crucial for the virus to enter the target cells, but whether an increase in ACE2 activity could facilitate the infect…
Effects of ACE-Inhibitors and Angiotensin Receptor Blockers on Inflammation
2011
The role of inflammation in cardiovascular disease and in hypertensive disease above all, is complex. Several studies confirm that activation of renin-angiotensin-aldosterone system (RAAS), through increase in the production of angiotensin II (Ang II), is closely related to local vascular inflammation. Over the BP lowering effects of anti-hypertensive treatments, several ancillary effects for every class may be found, distinguishing the various drugs from one another. Given the pro-inflammatory effects of Ang II and aldosterone, agents that interfere with the components of RAAS, such as ACE inhibitors, Angiotensin Receptor Blockers (ARBs), and mineralocorticoid receptor antagonists (spirono…
Free radical biology of the cardiovascular system
2012
Most cardiovascular diseases (CVDs), as well as age-related cardiovascular alterations, are accompanied by increases in oxidative stress, usually due to increased generation and/or decreased metabolism of ROS (reactive oxygen species; for example superoxide radicals) and RNS (reactive nitrogen species; for example peroxynitrite). The superoxide anion is generated by several enzymatic reactions, including a variety of NADPH oxidases and uncoupled eNOS (endothelial NO synthase). To relieve the burden caused by this generation of free radicals, which also occurs as part of normal physiological processes, such as mitochondrial respiratory chain activity, mammalian systems have developed endogen…
Mechanisms of Increased Vascular Superoxide Production in an Experimental Model of Idiopathic Dilated Cardiomyopathy
2005
Objective— In the present study, we sought to identify mechanisms underlying increased oxidative stress in vascular tissue in an experimental animal model of chronic congestive heart failure (CHF). Methods and Results— Superoxide and nitric oxide (NO) was measured in vessels from cardiomyopathic hamsters (CHF hamsters) and golden Syrian hamsters. We also determined expression of endothelial nitric oxide synthase (NOSIII), the soluble guanylyl cyclase, the cGMP-dependent kinase, and the NADPH oxidase. To analyze the contribution of the renin-angiotensin system to oxidative stress, CHF hamsters were treated with the angiotensin-converting enzyme inhibitor captopril for 200 days (120 mg · kg …