Search results for "renin-angiotensin system"

Unraveling the mechanisms of action of lactoferrin-derived antihypertensive peptides: ACE inhibition and beyond

2015

Hypertension is one of the most important causes of cardiovascular and renal morbidity and mortality, and it represents a serious health problem in Western countries. Over the last few decades scientific interest in food-derived antihypertensive peptides has grown as an alternative to drugs in the control of systemic blood pressure. Most of these peptides target the angiotensin I-converting enzyme (ACE) but emerging evidence points to other antihypertensive mechanisms beyond ACE inhibition. The milk protein lactoferrin (LF) is a good source of orally active antihypertensive peptides the characterization of which, including ex vivo functional assays and in vivo approaches, shows that they mi…

Efficacy and safety of combined neprilysin and RAS inhibition in heart failure: Let's leave the doubts behind

2020

Sodium zirconium cyclosilicate: a new potassium binder for the treatment of hyperkalemia

2018

Hyperkalemia is one of the most common electrolyte disturbances, especially among some groups of patients, such as in those with chronic kidney disease, diabetes or heart failure. Hyperkalemia has been associated with increased risks of mortality, arrhythmias, hospitalization and costs, as well as the need to down titrate/discontinue renin-angiotensin-aldosterone system inhibitors (RAASIs), despite their well-known cardiovascular and nephroprotective benefits. Current potassium binders have limitations (slow onset of action, limited selectivity for potassium binding, risk of drug interactions or gastrointestinal intolerance). Sodium zirconium cyclosilicate (SZC) is a new potassium binder re…

Delayed inhibition of angiotensin II receptor type 1 reduces secondary brain damage and improves functional recovery after experimental brain trauma*

2011

OBJECTIVE:: To investigate the regulation of the cerebral renin-angiotensin system and the effect of angiotensin II receptor type 1 inhibition on secondary brain damage, cerebral inflammation, and neurologic outcome after head trauma. DESIGN:: The expression of renin-angiotensin system components was determined at 15 mins, 3 hrs, 6 hrs, 12 hrs, and 24 hrs after controlled cortical impact in mice. Angiotensin II receptor type 1 was inhibited using candesartan (0.1, 0.5, 1 mg/kg) after trauma to determine its effect on secondary brain damage, brain edema formation, and inflammation. The window of opportunity was tested by delaying angiotensin II receptor type 1 inhibition for 30 mins, 1 hr, 2…

Age and Multimorbidity Predict Death Among COVID-19 Patients: Results of the SARS-RAS Study of the Italian Society of Hypertension

2020

Several factors have been proposed to explain the high death rate of the coronavirus disease 2019 (COVID-19) outbreak, including hypertension and hypertension-related treatment with Renin Angiotensin System inhibitors. Also, age and multimorbidity might be confounders. No sufficient data are available to demonstrate their independent role. We designed a cross-sectional, observational, multicenter, nationwide survey in Italy to verify whether renin-angiotensin system inhibitors are related to COVID-19 severe outcomes. We analyzed information from Italian patients diagnosed with COVID-19, admitted in 26 hospitals. One thousand five hundred ninety-one charts (male, 64.1%; 66±0.4 years) were r…

Serum uric acid is not independently associated with plasma renin activity and plasma aldosterone in hypertensive adults

2017

Background and Aims In experimental investigations conducted in rats, raising serum uric acid (SUA) levels resulted in the stimulation of intrarenal renin expression. Studies in humans exploring the association of SUA with plasma renin activity (PRA) yielded conflicting results. Moreover, little is known about the relationship of SUA with plasma aldosterone concentration (PAC). The study aimed to assess the relationship between SUA levels, PRA, and PAC and the influence of age, gender, body mass index (BMI), and hyperuricemia on these relationships in subjects with essential hypertension (EH). Methods and Results We enrolled 372 hypertensive patients (mean age 45 ± 12 years, men 67%) with u…

Renin-angiotensin system gene polymorphisms: relationship with blood pressure and microalbuminuria in telmisartan-treated hypertensive patients.

2004

This study analyzed the relationship between four renin–angiotensin system (RAS) gene polymorphisms and the response to blood pressure lowering and development of microalbuminuria in 206 patients with essential hypertension treated once daily for 12 months with telmisartan 80 mg. Seated cuff blood pressure and urinary albumin excretion (UAE) were measured throughout the study. Patients were screened for the presence of the A-6G variant of the angiotensinogen gene, angiotensin-converting enzyme insertion/deletion polymorphism, and the A1166C and C573T polymorphisms of the angiotensin II type 1 receptor gene. No significant association was found between the presence of any gene polymorphism a…

Angiotensin II contractile effects in mouse colon: role for pre- and post-junctional AT1A receptors

2013

Aim This study investigates whether a local renin–angiotensin system (RAS) exists in mouse colon and whether angiotensin II (Ang II) may play a role in the regulation of the contractile activity. Methods Isometric recordings were performed in vitro on the longitudinal muscle of mouse proximal and distal colon. Transcripts encoding for RAS components were investigated by RT-PCR. Results Ang II caused, in both preparations, a concentration-dependent contractile effect, antagonized by losartan, AT1 receptor antagonist, but not by PD123319, AT2 receptor antagonist. The combination of losartan plus PD123319 caused no change on the Ang II-induced contraction than losartan alone. Tetrodotoxin, neu…

Activation of angiotensin II type 1 receptors and contractile activity in human sigmoid colon in vitro.

2015

We propose and validate a non-invasive method that enables accurate detection of the discharge times of a relatively large number of motor units during excitatory and inhibitory reflex stimulations. HDsEMG and intramuscular EMG (iEMG) were recorded from the tibialis anterior muscle during ankle dorsiflexions performed at 5%, 10%, and 20% of the maximum voluntary contraction (MVC) force, in 9 healthy subjects. The tibial nerve (inhibitory reflex) and the peroneal nerve (excitatory reflex) were stimulated with constant current stimuli. In total, 416 motor units were identified from the automatic decomposition of the HDsEMG. The iEMG was decomposed using a state-of-the-art decomposition tool a…

The effect of RAAS blockade on markers of renal tubular damage in diabetic nephropathy: u-NGAL, u-KIM1 and u-LFABP.

2012

Blockade of the renin-angiotensin-aldosterone system (RAAS) affects both the glomerulus and tubules. We aimed to investigate the effect of irbesartan on the tubular markers: urinary (u) neutrophil gelatinase associated protein (NGAL), Kidney injury molecule 1 (KIM1) and liver-fatty acid-binding protein (LFABP).A substudy of a double-masked, randomized, cross-over study including 52 patients with type 2 diabetes, hypertension and microalbuminuria. After 2 months washout of all antihypertensive medication except bendroflumethiazid, patients were treated in random order with irbesartan 300, 600 and 900 mg for 2 months.Urinary tubular markers at baseline and after each treatment period (ELISA),…