Angiotensins (Total 67626 Papers Found)

The recent discovery of the angiotensin II (Ang II)-breakdown enzyme, angiotensin I converting enzyme (ACE) 2, suggests the importance of Ang II degradation in hypertension. The present study explored the signaling mechanism by which ACE2 is regulated under hypertensive conditions. Real-time PCR and immunohistochemistry showed that ACE2 mRNA and protein expression levels were high, whereas ACE expression levels were moderate in both normal kidney and heart. In contrast, patients with hypertensio ...
The 4 kDa beta-amyloid peptide that forms the amyloid fibrils in the brain parenchyma of Alzheimer's disease patients is derived from the larger integral membrane protein, the amyloid precursor protein. In the nonamyloidogenic pathway, alpha-secretase cleaves the amyloid precursor protein within the beta-amyloid domain, releasing an extracellular portion and thereby preventing deposition of the intact amyloidogenic peptide. The release of the amyloid precursor protein from both SH-SY5Y and IMR-3 ...
Ischemic heart disease and stroke are the leading causes of death worldwide. A large proportion of individuals at high 10-year risk of a cardiovascular event live in low-income and middle-income countries, and the large majority of all cardiovascular events occur in developing countries. A large amount of evidence supports the use of pharmacological treatment for the prevention of cardiovascular death in this population, including antiplatelet drugs, beta blockers, lipid-lowering agents and angi ...
Because of the enormous growth over the last three decades of research on the role of peptides in the brain, the need became apparent to determine the status of these compounds in terms of their current research interest. Since 1965, over a quarter of a million research papers have been published on peptides that have since been classified as neuroactive. The present study was undertaken to analyze systematically the yearly trends of research emphasis in neuroactive peptides as reflected by thei ...
Hypothalamic norepinephrine (NE) release regulates arterial pressure by altering sympathetic nervous system activity. Because angiotensin (Ang) (1-7) decreases hypothalamic NE release and this effect may be correlated with a diminished NE synthesis, we hypothesize that Ang-(1-7) down-regulates tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamines biosynthesis. We investigated the effect of Ang-(1-7) on centrally TH activity and expression. TH activity was evaluated by the release ...
Accumulating evidence indicates cyclooxygenase (COX) 1 and COX2 differentially regulate cardiovascular and renal function. We have demonstrated previously in mice that COX2 inhibition enhances angiotensin II-induced hypertension, and COX1 inhibition attenuates the pressor effect of angiotensin II. To further elucidate the mechanism underlying the functional difference of COX1 versus COX2 inhibition, the present studies examined the prostaglandin (PG) profiles derived in COX1- or COX2-inhibited m ...
High-density oligonucleotide arrays were used to compare gene expression of rat hearts from control, untreated diabetic, and diabetic groups treated with islet cell transplantation (ICT), protein kinase C (PKC)beta inhibitor ruboxistaurin, or ACE inhibitor captopril. Among the 376 genes that were differentially expressed between untreated diabetic and control hearts included key metabolic enzymes that account for the decreased glucose and increased free fatty acid utilization in the diabetic hea ...
BACKGROUND Aliskiren is a relatively new oral direct renin inhibitor (DRI) that has been increasingly used for the treatment of diabetic nephropathy and hypertension. Its potential efficacy in nondiabetic chronic kidney diseases that are driven by renin-angiotensin system activation remains to be explored. METHODS From a teaching and regional hospital in Hong Kong between July 2009 and March 2010, patients with biopsy-proven immunoglobulin A nephropathy (IgAN) in whom the ratio of protein to c ...
To determine whether moderate restriction of dietary sodium content or supplementation of potassium intake reduces blood-pressure in patients with mild essential hypertension, twelve patients were put on three different diets--a control diet (180 mmol sodium/day), a sodium restricted diet (80 mmol/day). Each diet was taken for at least 4 weeks and the sequence of the regimens was randomised. At the completion of each regimen intra-arterial pressure was recorded continuously, and vasoactive hormo ...
Arterial rings were prepared from the branchial artery, coeliac artery and ventral aorta of the Japanese dogfish Triakis scyllia and used to determine arterial contraction in a myograph. Noradrenaline caused a dose-dependent contraction (10(-9)-3 x 10(-6) M) that was completely inhibited by pre-treatment with 10(-7) M phentolamine. Homologous dogfish angiotensin II (ANG II) ([Asn1, Pro3, Ile5]-ANG II) also caused dose-dependent contraction (10(-9)-3 x 10(-6) M), but phentolamine had no effect on ...
BACKGROUND Erythropoiesis-stimulating agent (ESA) resistance remains incompletely understood among hemodialysis (HD) patients. METHOD A retrospective, multicenter study was designed to analyze data from 1,934 patients followed for up to two years. The outcome measure was the erythropoietin resistance index (ERI), defined as erythropoietin dosage over a week divided by the post-HD weight and hemoglobin value. RESULTS Multivariate analysis revealed albumin, Kt/V, transferrin saturation, statin ...
The circadian (about 24-hr) oscillating function of the renin-angiotensin-aldosterone system (RAAS) was investigated as a function of age in clinically healthy participants and in essential hypertensive patients. A peculiar age-related decline in the RAAS circadian mesor (rhythm-adjusted mean) and amplitude (variability from mesor) was found in the essential hypertensive patients. This finding suggests a nonphysiologic evolution in the tonic (24-hr mean level) as well as phasic (oscillating ampl ...
Objective Fixed-dose combination (FDC) prescribing enhances adherence to medication. However, there are limited data regarding the usefulness of FDC drugs across different risk groups. The aim of this study was to explore the relationship between FDC discontinuation and clinical outcomes. Methods From January 2008 to December 2014, patients with FDC prescriptions who visited a cardiology outpatient clinic at a tertiary university hospital in Daegu, Republic of Korea were retrospectively identi ...
Angiotensin converting enzyme (ACE) is identical with kininase II. Besides reducing the production of angiotensin II, inhibition of ACE potentiates the biological actions of endogenous kinins. In hypertension-induced left ventricular hypertrophy, potentiation of endogenous kinins contributes to the improvement of cardiac function and energy metabolism and to capillary proliferation effected by ACE inhibitors. In myocardial infarction (MI), the potentiation of kinins has been shown to be involved ...
Previous studies have reported bimodal effects by angiotensin II (Ang II) in the rat internal anal sphincter (IAS), a concentration-dependent contraction (at lower concentrations) and relaxation (at higher concentrations). The experiments suggest the above-mentioned responses are the result of Ang II subtype I receptor(s) (AT(1)-R) and subtype II receptor(s) (AT(2)-R) activation, respectively. These studies determined the role and mechanism of AT(2)-R-induced relaxation of the smooth muscle cell ...
OBJECTIVE Angiotensin-converting enzyme inhibitor (ACEI) has been demonstrated to have protective effect for patients with mild to moderate chronic kidney disease (CKD). However, little evidence is available for the benefit or side-effects of ACEI in treating patients with more severe CKD. A prospective, randomized controlled trial was performed to evaluate the renal protective effect and safety of ACEI in patients whose serum creatinine (Scr) levels were higher than 265 micromol/L. METHODS 16 ...
High blood pressure (HBP) is a multifactorial disease that affects millions of people around the world and contributes to a large number of deaths due to acute myocardial infarction, stroke and chronic kidney disease. Its etiology remains inconclusive, but it is known that it arises of central and peripheral catecholaminergic dysfunction. Thus, cellular mechanisms are still under investigation. Its pathophysiology is characterized by an increase in systolic and diastolic blood pressure levels. T ...
Nephrectomized rats have above-normal plasma prorenin levels, presumably of extra-renal origin, but essentially no renin, suggesting a lack of "convertase" for prorenin activation. Adrenalectomized rats have low plasma prorenin levels accompanied by high renin activity, suggesting enhanced prorenin activation by the action of a stimulated "convertase" mechanism. Cross-circulation between adrenalectomized and nephrectomized rats for 15 or 30 minutes, dramatically lowered prorenin and raised renin ...
We examined the changes in glomerular hemodynamics produced by angiotensin II (AII) in both normal Munich-Wistar rats and rats which were unilaterally renal denervated (measured kidney) 4-6 d prior to the measurement periods. Measurements of glomerular dynamics were performed in a control period after plasma volume expansion and during infusion of 11 ng X 100 g body wt-1 X min-1 of AII. The glomerular hydrostatic pressure gradient increased from 38 +/- 1 to 49 +/- 1 mmHg in denervated rats compa ...
We investigated the effect of chronic angiotensin-covering enzyme (ACE) inhibitor treatment on functional and biochemical cardiac parameters in stroke-prone spontaneously hypertensive rats (SHRsp). Animals were treated prenatally and, subsequently, up to the age of 20 weeks with the ACE inhibitor perindopril (0.01 and 1 mg/kg per day). The contribution of endogenous bradykinin potentiation to the actions of the ACE inhibitor was assessed by co-treatment with the bradykinin B2-receptor antagonist ...
To test whether angiotensin-converting enzyme (ACE) inhibition may prevent myocardial damage and may affect coronary microvasculature in spontaneously hypertensive rats (SHR), young 5-week-old SHR were treated for 3 months with spirapril and changes in blood pressure (BP) were monitored. Untreated SHR were used as controls. The rats were killed; left ventricular (LV) shape, weight, and wall thickness were examined and the ventricular myocardium was analyzed morphometrically to determine the effe ...
Atrial fibrillation (AF) is a source of considerable morbidity and mortality. There has been compelling evidence supporting the role of renin-angiotensin system (RAS) in the genesis and perpetuation of AF through atrial remodeling, and experimental studies have validated the utilization of RAS inhibition for AF prevention. This article reviews clinical trials on the use of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) for the prevention of AF. Results ...
The influence of sex on the vascular response during the progression of myocardial infarction (MI) has not been extensively studied. In this work, we analyzed the differences of the vasoconstriction induced by angiotensin II (Ang II) in the absence and presence of valsartan (200 nM) on the aortic rings of male and female Wistar rats at 2, 4, 24, and 48 hours and 1, 2, 3, and 4 weeks after induction of MI. In the aortic rings of males, an increase was observed in the contractile response that las ...
OBJECTIVES Transient administration of inhibitors of the renin-angiotensin system (RAS) during the prehypertensive period in rats and humans leads to a long-lasting lowering of blood pressure (BP). Our aim was to unravel the critical period in which activation of the RAS induces chronic effects on BP and to determine the role of renal function and structure in this process. METHODS Studies were performed in Cyp1a1-Ren2 rats, which harbor a construct for the production of mouse renin. This cons ...
BACKGROUND The effects of type 1 angiotensin II receptor antagonist losartan and its metabolite E3174 on transmembrane action potentials, hKv1.5, HERG, and I(Ks) currents were analyzed. METHODS AND RESULTS Guinea pig ventricular action potentials were recorded with microelectrode techniques and hKv1.5 and HERG currents with the whole-cell patch-clamp technique. I(Ks) was recorded in guinea pig ventricular myocytes with the perforated-nystatin-patch configuration. Losartan and E3174 transiently ...
Atrial natriuretic peptide II (ANP II) raises cyclic GMP and relaxes vascular smooth muscle in vitro. The manner in which ANP II relaxes vascular smooth muscle is unknown but may involve alterations in the concentration of free intracellular Ca++. To examine this possibility, changes in intracellular Ca++ were monitored in rat aortic strips using the Ca++-dependent conversion of phosphorylase b to a, while Ca++ levels and phosphorylase were measured in cultured rat aortic smooth muscle cells. AN ...
Several clinical trials have consistently shown that antihypertensive treatment, particularly with angiotensin-converting enzyme inhibitors (ACE-I) reduces albuminuria in Type 1 diabetic patients. More recently, data on the beneficial effects of ACE-I on the preservation of glomerular filtration rate and renal ultrastructure have emerged. However, in general, these trials have recruited a wide spectrum of diabetics, including some patients with severe albuminuria. Thus, the question of the ideal ...
Selective alpha1-adrenoreceptor blockers were recently reported to have an in vivo antiproliferative effect on hypertensive cardiovascular organs. Cultured vascular smooth-muscle cells (VSMCs) from spontaneously hypertensive rats (SHRs) show exaggerated growth compared with cells from Wistar-Kyoto (WKY) rats. We investigated the effects of an alpha1-adrenoreceptor blocker, bunazosin hydrochloride (HCl), on the growth of VSMCs from SHRs. In the absence of serum, bunazosin HCl significantly inhibi ...
Aside from its established immunologic and hematologic functions, the spleen also plays an important role in cardiovascular regulation. This occurs through changes in intrasplenic microvascular tone, as well as through splenic neurohormonal modulation of the renal and mesenteric vascular beds. Splenic regulation of blood volume occurs predominantly through fluid extravasation from the splenic circulation into lymphatic reservoirs; this is controlled by direct modulation of splenic pre- and postc ...
The effect of rat atrial natriuretic peptide (rANP) on hormonal stimulated osmotic water permeability (Jw, hydrosmotic effect) and net ion transport (short-circuit current, SCC, natriferic effect) was studied on toad skin, a tissue with functional similarities to the mammalian distal nephron, in order to assess actions on transport mechanisms. Rat atrial natriuretic peptide, rANP-99-126 (rANP) inhibited stimulated SCC and Jw to submaximal concentrations of arginine vasotocin (AVT) at a site befo ...
BACKGROUND The response of proximal convoluted tubules (PCTs) to angiotensin II is mediated by specific type 1 receptors found on both apical and basolateral surface membrane cells. After ligand association with type 1 receptors, different signaling pathways are triggered and determine changes in fluid absorption (Jv). The presence of AT1 and actin cytoskeleton, which are directly related to Jv, can undergo changes in distribution based on the actions of AngII and losartan. METHODS Using a mic ...
Microdialysis was used to assess the interstitial concentrations of glucose and lactate in the constant-flow-perfused rat hindlimb under varying levels of nutritive flow controlled by vasoconstrictors. Increased nutritive flow was achieved by norepinephrine (NE) or angiotensin II (ANG II) and decreased nutritive flow by serotonin (5-HT). NE and ANG II increased oxygen and glucose uptake as well as hindlimb lactate release by 50%. 5-HT decreased oxygen uptake by 15% but had no significant effect ...
The present experiments were devoted to analyzing the hypothesis that somatostatin (SS) could modulate glomerular filtration rate by interacting with mesangial cells. Studies were performed in cultured human mesangial cells, passages 3-5. Radioligand experiments demonstrated the presence in the cells of two kinds of receptors, with high (dissociation constant 14 pM. Number of sites: 426 fmol/mg) and low (dissociation constant 56 pM. Number of sites: 20, 111 fmol/mg) affinity. SS prevented in a d ...
We investigated the effects of phorbol myristate acetate (PMA) on metabolic pulmonary endothelial ectoenzyme dysfunction. Anesthetized rabbits were placed on total heart bypass, and the single-pass transpulmonary metabolism of [3H]benzoyl-Phe-Ala-Pro (BPAP) by endothelial-bound angiotensin-converting enzyme (ACE) and [14C]adenosine 5'-monophosphate (AMP) by 5'-nucleotidase (NCT) was calculated before and after PMA (10 micrograms/kg iv), a dose that does not produce histologically evident endothe ...
In der vorliegenden Arbeit wurde überprüft, ob bei pulmonaler Hypertonie (PH) eine im Vergleich zu regelrechtem Lungengewebe vermehrte ACE-Expression vorliegt und diese mit bestimmten Hypertonieformen korreliert. Die ACE-Antigenexpression wurde immunhistochemisch an 33 morphologisch regelrechten Lungengewebeproben (19 Männer, 32–77 J.; 14 Frauen, 34–93 J.) sowie Lungengewebeproben von 94 Patienten (67 Männer, 30–97 J.; 27 Frauen: 27–90 J.) mit klinisch gesicherter PH unterschiedli ...
The effects and mechanism of the extract of Radix Scrophulariae (ERS), a traditional Chinese herb, on experimental ventricular remodeling in rats was studied. Rats were separated randomly into 5 groups: sham, model, captopril (40 mg x kg(-1)) and ERS (8, 16 g x kg(-1)). The experimental ventricular remodeling was induced with ligating the left anterior descending branch of the coronary artery of the rats. The sham group was conducted the same procedure without ligation. After 4 weeks treatment w ...
Tachycardia accompanying exercise shortens the duration of diastole, reducing the time available for the left ventricular (LV) filling. Thus, the LV must fill more rapidly for the stroke volume to increase (or even be maintained) during exercise. Normally, this is accomplished without requiring an excessive increase in left atrial (LA) pressure by an acceleration of LV relaxation and a fall in LV early diastolic pressure during exercise. This response is lost following the development of heart f ...
Recent studies have shown that, not only in hypertensive animals but even in normotensive rats, dietary salt (sodium chloride) produces a dose-related increase in the left ventricular and renal mass. In the present study the effects of the angiotensin converting enzyme inhibitor (ACEI) enalapril and the thiazide-type diuretic, hydrochlorothiazide, on the development of the salt-induced left ventricular and kidney hypertrophy were examined in normotensive Wistar-Kyoto and Wistar rats. A high inta ...
Forty-one patients with mild essential hypertension, 36 patients with severe hypertension, and 28 normotensive subjects were studied on a high sodium intake of 350 mmol/day for five days and low sodium intake of 10 mmol/day for five days. The fall in mean arterial pressure on changing from the high-sodium to the low-sodium diet was 0.7 +/- 1.7 mm Hg in normotensive subjects, 8 +/- 1.4 mm Hg in patients with mild hypertension, and 14.5 +/- 1.4 mm Hg in patients with severe hypertension. The fall ...
Semantic Scholar extracted view of "TITLE: Nephrogenesis and the renal renin-angiotensin system in fetal sheep: effects of intrauterine growth restriction during late gestation AUTHORS:" by Vladislava Zohdi et al. ...
OBJECTIVE Abdominal aortic aneurysm (AAA) is a complex vascular disease characterized by matrix degradation and inflammation and is a major cause of mortality in older men. Specific interventions that prevent AAA progression remain to be identified. In this study, we tested the hypothesis that Group X secretory phospholipase A(2) (GX sPLA(2)), an enzyme implicated in inflammatory processes, mediates AAA. METHODS AND RESULTS GX sPLA(2) was detected by immunostaining in human aneurysmal tissue a ...
  • ,
  • Herz Kardiovaskuläre Erkrankungen
  • 2006
Patienten, bei denen im Rahmen einer Angiographie eine kontrastmittelinduzierte Nephropathie (KIN) auftritt, weisen eine signifikant erhöhte Morbidität und Mortalität auf. Substanzen, die eine Vasokonstriktion vermeiden und zu einer Steigerung der glomerulären Filtrationsrate (GFR) führen, sind potentiell in der Lage, eine KIN zu verhindern. Eine direkte, intrarenale Verabreichung kann diese Effekte zusätzlich steigern und außerdem systemische Nebenwirkungen reduzieren. Die Substanz Nesir ...
  • ,
  • 2002
The surprising aspect of this article is not the popularity of its subject, but that it appeared at all. When I wrote it at the request of a great editor, Robert Berne, I did not know that he would send it to 10 reviewers. Most of them tried to correct errors in the manuscript, but some used the opportunity to offer a free psychoanalysis of the writer and tried to improve his character instead of the style or content of the article. I literally threw the manuscript into a drawer designated as it ...
BACKGROUND Cardiovascular disease (CVD) places a significant burden on healthcare providers. High blood pressure (BP) is the single most prevalent risk factor for CVD worldwide and is responsible for more deaths than any other risk factor. 'Cardiovascular (CV) high-risk patients' make up the broad cross-section of patients in the middle of the risk spectrum for CVD progression that is referred to as the CV continuum and includes those with atherothrombotic disease, those with target organ damage ...
Prostaglandin E2 (PGE2) is an endogenous hormone of adrenal zona glomerulosa cells and is released in response to stimulation by agonists such as angiotensin II (Ang II). It stimulates the release of aldosterone from cultured bovine adrenal zona glomerulosa cells. These studies were designed to determine whether this steroidogenic effect of PGE2 was mediated by an EP1, EP2, or EP3 receptor. Prostaglandin E2 and 11-deoxy PGE1, an EP2-selective agonist, stimulated aldosterone release in a concentr ...
Twenty-four patients, each with advanced bladder cancer (BC) or brain tumor (BT), were treated by intraarterial infusion of angiotensin II in combination with DDP as the main drug together with other anticancer drugs. As for the frequency of treatment by the intraarterial therapy, only one course was given in 15 cases, two courses in 9 (BC), one course in 21 cases, and two courses in 3 (BT). CR was obtained in ten of 24 evaluable patients with BC and PR in eleven. Of 20 evaluable patients with B ...
We studied the actions of the proteinase-activated receptor-2-activating peptide (PAR2-AP) trans-cinnamoyl-LIGRLO-amide (tc-LI) in femoral (FA), renal, and small mesenteric (MA) arterial vessels from C57BL/6 [PAR2 (+/+)] and PAR2 (-/-) mice. The actions of tc-LI were compared with those of the parent PAR2-AP Ser-Leu-Ile-Gly-Arg-Leu-amide (SLIGRL-amide; SLI-NH2). Either SLI-NH2 or tc-LI (0.1-10 microM) induced relaxation of either 9,11-dideoxy-9alpha,11alpha-methanoepoxy-prosta-5Z,13E-dien-1-oic ...
BACKGROUND To investigate plasma renin activity and aldosterone serum concentrations in severe preeclampsia (PE) or HELLP-syndrome. METHODS We measured plasma renin activity and serum concentrations of aldosterone, progesterone, estradiol and estriol in 16 patients with PE and 14 patients with HELLP-syndrome and in well-matched normotensive pregnant controls. Additionally, the umbilical venous levels of aldosterone and plasma renin activity were determined in ten corresponding newborns. RESU ...