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Many patients undergoing surgical procedures have a history of hypertension, diabetes mellitus, heart failure, or a combination. Often, these conditions involve the chronic use of a renin–angiotensin system inhibitor, including angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs). Observational studies have suggested that continuing ACEIs/ARBs before major noncardiac surgery can increase the risk of intraoperative hypotension, which might drive postoperative complications such as acute kidney injury, myocardial injury, or stroke. Strong recommendations on how to manage ACEIs/ARBs before surgery are, however, lacking owing to insufficient evidence, mostly limited to data from observational studies. Recently, the SPACE trial investigated the impact of preoperative management of ACEIs/ARBs on postoperative myocardial injury. Myocardial injury occurred in 48.3% patients randomised to discontinue and 41.3% patients randomised to continue ACEI/ARB (odds ratio for continuing: 0.77, 95% confidence interval 0.45–1.31). Patients randomised to the 'Stop' group experienced more postoperative hypertension. In a post hoc analysis, patients randomised to the 'Continue' group with low preoperative NT-proBNP concentrations (<100 pg ml−1) experienced less myocardial injury after surgery than the 'Stop' group, whereas no significant difference was observed in patients with elevated preoperative NT-proBNP concentrations. The SPACE trial provides important and new reassuring data on the safety of continuing ACEIs/ARBs before major surgery, challenging previous beliefs. [ABSTRACT FROM AUTHOR]

Since the 1950s, sodium polystyrene sulphonate (SPS) has been the dominant cation exchange agent prescribed for hyperkalaemia. Clinicians have had plenty of time to learn of SPS's advantages and limitations. The demands of drug regulatory agencies regarding the incorporation of medications into the market were not so stringent then as they are today, and the efficacy and safety of SPS have been questioned. In recent years, two novel cation exchangers, patiromer and sodium zirconium cyclosilicate, have received (or are in the process of receiving) regulatory approval in multiple jurisdictions globally, after scrutiny of carefully conducted trials regarding their short-term and mid-term efficacy. In this debate, we defend the view that all three agents are likely to have similar efficacy. Harms are much better understood for SPS than for newer agents, but currently there are no data to suggest that novel agents are safer than SPS. Drug choices need to consider costs, access and numbers-needed-to-treat to prevent clinically important events; for potassium exchangers, we need trials directly examining clinically important events. [ABSTRACT FROM AUTHOR]

Type 2 diabetes (T2DM) is one of the main public health care problems worldwide. It is associated with a marked increased risk of developing atherosclerotic vascular disease, heart failure, chronic kidney disease and death. It is essential to act during the early phases of the disease, through the intensification of lifestyle changes and the prescription of those drugs that have been shown to reduce these complications, with the aim not only of achieving an adequate metabolic control, but also a comprehensive vascular risk control. In this consensus document, developed by the different specialists that treat these patients (endocrinologists, primary care physicians, internists, nephrologists and cardiologists), a more appropriate approach in the management of patients with T2DM or its complications is provided. A particular focus is given to the global control of cardiovascular risk factors, the inclusion of weight within the therapeutic objectives, the education of patients, the deprescription of those drugs without cardiovascular benefit, and the inclusion of GLP-1 receptor agonists and SGLT2 inhibitors as cardiovascular protective drugs, at the same level as statins, acetylsalicylic acid, or renin angiotensin system inhibitors. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) represents an enormous healthcare burden, the management of which has been stagnant for the last couple of decades, with blockade of the renin--angiotensin--aldosterone system (RAAS) the most potent tool available to retard kidney disease progression. In the new cardiometabolic era, sodium-glucose cotransporter-2 inhibitors (SGLT2i) have emerged as forerunners in addressing combined cardiorenal risk. This review summarises the evidence for SGLT2i use in diabetic and non-diabetic CKD and examines the risk:benefit profile in this population. Novel non-steroidal mineralocorticoid receptor antagonists are also considered as an emerging pillar of CKD management, and their role in optimising the cardiorenal health of patients with diabetic kidney disease is discussed. [ABSTRACT FROM AUTHOR]

Objective: To estimate the prevalence, incidence, and describe the characteristics and management of patients with heart failure with preserved (HFpEF), mildly reduced (HFmrEF), and reduced ejection fraction (HFrEF) in Spain. Methods: Adults with ≥1 inpatient or outpatient HF diagnosis between 1 January 2013 and 30 September 2019 were identified through the BIG-PAC database. Annual incidence and prevalence by EF phenotype were estimated. Characteristics by EF phenotype were described in the 2016 and 2019 HF prevalent cohorts and outcomes in the 2016 HF prevalent cohort. Results: Overall, HF incidence and prevalence were 0.32/100 person-years and 2.34%, respectively, but increased every year. In 2019, 49.3% had HFrEF, 38.1% had HFpEF, and 4.3% had HFmrEF (in 8.3%, EF was not available). Compared with HFrEF, patients with HFpEF were largely female, older, and had more atrial fibrillation but less atherosclerotic cardiovascular disease. Among patients with HFrEF, 76.3% were taking renin-angiotensin system inhibitors, 69.5% beta-blockers, 36.8% aldosterone antagonists, 12.5% sacubitril/valsartan and 6.7% SGLT2 inhibitors. Patients with HFpEF and HFmrEF took fewer HF drugs compared to HFrEF. Overall, the event rates of HF hospitalization were 231.6/1000 person-years, which is more common in HFrEF patients. No clinically relevant differences were found in patients with HFpEF, regardless EF (50- < 60% vs. ≥60%). Conclusions: >2% of patients have HF, of which around 50% have HFrEF and 40% have HFpEF. The prevalence of HF is increasing over time. Clinical characteristics by EF phenotype are consistent with previous studies. The risk of outcomes, particularly HF hospitalization, remains high, likely related to insufficient HF treatment. [ABSTRACT FROM AUTHOR]

A convincing deal of evidence supports the fact that severe psoriasis is associated with cardiovascular diseases. However, the precise underlying mechanisms linking psoriasis and cardiovascular diseases are not well defined. Psoriasis shares common pathophysiologic mechanisms with atherosclerosis and cardiovascular (CV) risk factors. In particular, polymorphism in the IL-23R and IL-23 genes, as well as other genes involved in lipid and fatty-acid metabolism, renin–angiotensin system and endothelial function, have been described in patients with psoriasis and with cardiovascular risk factors. Moreover, systemic inflammation in patients with psoriasis, including elevated serum proinflammatory cytokines (e.g., TNF-α, IL-17, and IL-23) may contribute to an increased risk of atherosclerosis, hypertension, alteration of serum lipid composition, and insulin resistance. The nonlinear and intricate interplay among various factors, impacting the molecular pathways in different cell types, probably contributes to the development of psoriasis and cardiovascular disease (CVD). Future research should, therefore, aim to fully unravel shared and differential molecular pathways underpinning the association between psoriasis and CVD. [ABSTRACT FROM AUTHOR]

The renin–angiotensin system (RAS) plays a crucial role and coordinates multiple body functions through its hormonal mechanism. The RAS is supported in its function by numerous peptides such as angiotensin II (Ang II), Ang IV, Ang III, angiotensin (1-7) and (1-9). The system formed by ACE2/Ang(1-7)/MASr is a regulatory pathway within the RAS system and its functions are different from those of the ACE/Ang II/AT-1r system. Recently, it has been discovered that a key role of the RAS and the ACE2/Ang(1-7)/MASr system is in inflammatory processes such as cardiac hypertrophy and heart failure. Studies are ongoing to better understand and comprehend the function of the RAS in inflammation. Recent evidence associates AT-1r antagonists with a cardioprotective, anti-inflammatory, and anti-hypertrophic role. In this in vitro study, we demonstrate the protective role of treatment (50 and 200 μM) of an AT-1r antagonist, irbesartan, on hypoxia and inflammation-induced damage in cardiomyocytes. [ABSTRACT FROM AUTHOR]

Objectives To assess mortality and cardiovascular and renal outcomes among patients with chronic kidney disease (CKD) (primary objective), with a particular focus on heart failure (HF) risk following diagnosis of CKD (secondary objective) in Spain. Methods We conducted an observational study comprising cross-sectional and longitudinal retrospective analyses using secondary data from electronic health records. For the primary objective, adults with prevalent CKD [estimated glomerular filtration rate (eGFR) <60 or ≥60 mL/min/1.73 m2 with a urine albumin:creatinine ratio (UACR) ≥30 mg/g at the index date (1 January 2017)] were included. For the secondary objective, adults with incident CKD in 2017 were enrolled. Results In the prevalent population, 46 786 patients with CKD without HF [75.8 ± 14.4 years, eGFR 51.4 ± 10.1 mL/min/1.73 m2; 75.1% on renin–angiotensin system inhibitors (RASis)] and 8391 with CKD and HF (79.4 ± 10.9 years, eGFR 46.4 ± 9.8 mL/min/1.73 m2) were included. In the prevalent population, the risk of all-cause death {hazard ratio [HR] 1.107 [95% confidence interval (CI) 1.064–1.153]}, HF hospitalization [HR 1.439 (95% CI 1.387–1.493)] and UACR progression [HR 1.323 (95% CI 1.182–1.481)] was greater in those patients with CKD and HF versus CKD only. For the incident population, 1594 patients with CKD without HF and 727 with CKD and HF were included. Within 24 months from the CKD diagnosis (with/without HF at baseline), 6.5% of patients developed their first HF hospitalization. Although 60.7% were taking RASis, only 3.4% were at maximal doses and among diabetics, 1.3% were taking sodium-glucose cotransporter-2 inhibitors. Conclusions The presence of HF among CKD patients markedly increases the risk of outcomes. CKD patients have a high risk of HF, which could be partially related to insufficient treatment. [ABSTRACT FROM AUTHOR]

Background Hyperkalaemia is an electrolyte abnormality associated with adverse clinical outcomes; however, few studies have investigated the relationship with patterns of hyperkalaemia over time. This study explored the impact of time spent in a hyperkalaemic state and variability of serum potassium (sK+) on major adverse cardiovascular events (MACE) and all-cause mortality in patients with chronic kidney disease (CKD), resistant hypertension, heart failure and diabetes. Methods Cohorts comprised adult patients diagnosed with CKD stage 3+, resistant hypertension, heart failure or diabetes, and/or renin–angiotensin–aldosterone system inhibitor prescription, between 1 January 2003 and 30 June 2018, from the UK Clinical Practice Research Datalink. Associations between percentage of follow-up spent in a hyperkalaemic state (sK+ ≥5.0 mmol/L, ≥5.5 mmol/L, ≥6.0 mmol/L) or sK+ variability (standard deviation above or below median standard deviation) and all-cause mortality or MACE were investigated. Results For sK+ ≥5.0 mmol/L, time spent in a hyperkalaemic state was associated with reduced risk of all-cause mortality across all cohorts. For higher sK+ thresholds, this trend was attenuated or reversed; for time spent in a hyperkalaemic state at sK+ ≥6.0 mmol/L, an increased risk of mortality was seen in the overall cohort and for patients with diabetes, resistant hypertension or prescribed renin–angiotensin–aldosterone system inhibitors, with no consistent association seen for patients with CKD or heart failure. Risk of MACE in the overall cohort and in patients with CKD, diabetes or resistant hypertension increased with time spent in a hyperkalaemic state at all sK+ thresholds; however, no correlation was seen in patients with heart failure or those receiving dialysis. High sK+ variability was associated with a higher risk of MACE compared with low sK+ variability across most sK+ categories in the overall population and in all disease cohorts, except patients on dialysis; however, no association between sK+ variability and all-cause mortality was observed. Conclusions Patterns of hyperkalaemia, including time spent in hyperkalaemia and sK+ variability, are associated with adverse clinical outcomes. Regular monitoring of sK+ in high-risk populations in broader community, primary care and outpatient settings may enable guideline-recommended management of hyperkalaemia and help avoid adverse events. [ABSTRACT FROM AUTHOR]

Neuropeptide Y (NPY) is a 36-amino-acid peptide member of a family also including peptide YY and pancreatic polypeptide, which are all ligands to Gi/Go coupled receptors. NPY regulates several fundamental biologic functions including appetite/satiety, sex and reproduction, learning and memory, cardiovascular and renal function and immune functions. The mesenteric circulation is a major source of NPY in the blood in man and this peptide is considered a key regulator of gut–brain cross talk. A progressive increase in circulating NPY accompanies the progression of chronic kidney disease (CKD) toward kidney failure and NPY robustly predicts cardiovascular events in this population. Furthermore, NPY is suspected as a possible player in accelerated cognitive function decline and dementia in patients with CKD and in dialysis patients. In theory, interfering with the NPY system has relevant potential for the treatment of diverse diseases from cardiovascular and renal diseases to diseases of the central nervous system. Pharmaceutical formulations for effective drug delivery and cost, as well as the complexity of diseases potentially addressable by NPY/NPY antagonists, have been a problem until now. This in part explains the slow progress of knowledge about the NPY system in the clinical arena. There is now renewed research interest in the NPY system in psychopharmacology and in pharmacology in general and new studies and a new breed of clinical trials may eventually bring the expected benefits in human health with drugs interfering with this system. [ABSTRACT FROM AUTHOR]

Background Users of guideline-recommended renin–angiotensin–aldosterone system (RAAS) inhibitors may experience disruptions to their treatment, e.g. due to hyperkalaemia, hypotension or acute kidney injury. The risks associated with treatment disruption have not been comprehensively assessed; therefore, we evaluated the risk of adverse clinical outcomes in RAAS inhibitor users experiencing treatment disruptions in a large population-wide database. Methods This exploratory, retrospective analysis utilized data from the UK's Clinical Practice Research Datalink, linked to Hospital Episodes Statistics and the Office for National Statistics databases. Adults (≥18 years) with first RAAS inhibitor use (defined as angiotensin-converting enzyme inhibitors or angiotensin receptor blockers) between 1 January 2009 and 31 December 2014 were eligible for inclusion. Time to the first occurrence of adverse clinical outcomes [all-cause mortality, all-cause hospitalization, cardiac arrhythmia, heart failure hospitalization, cardiac arrest, advancement in chronic kidney disease (CKD) stage and acute kidney injury] was compared between RAAS inhibitor users with and without interruptions or cessations to treatment during follow-up. Associations between baseline characteristics and adverse clinical outcomes were also assessed. Results Among 434 027 RAAS inhibitor users, the risk of the first occurrence of all clinical outcomes, except advancement in CKD stage, was 8–75% lower in patients without interruptions or cessations versus patients with interruptions/cessations. Baseline characteristics independently associated with increased risk of clinical outcomes included increasing age, smoking, CKD, diabetes and heart failure. Conclusions These findings highlight the need for effective management of factors associated with RAAS inhibitor interruptions or cessations in patients for whom guideline-recommended RAAS inhibitor treatment is indicated. [ABSTRACT FROM AUTHOR]

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected individuals that have hypertension or cardiovascular comorbidities have an elevated risk of serious coronavirus disease 2019 (COVID-19) disease and high rates of mortality but how COVID- |$19$| and cardiovascular diseases interact are unclear. We therefore sought to identify novel mechanisms of interaction by identifying genes with altered expression in SARS-CoV- |$2$| infection that are relevant to the pathogenesis of cardiovascular disease and hypertension. Some recent research shows the SARS-CoV- |$2$| uses the angiotensin converting enzyme- |$2$| (ACE- |$2$|⁠) as a receptor to infect human susceptible cells. The ACE2 gene is expressed in many human tissues, including intestine, testis, kidneys, heart and lungs. ACE2 usually converts Angiotensin I in the renin–angiotensin-aldosterone system to Angiotensin II, which affects blood pressure levels. ACE inhibitors prescribed for cardiovascular disease and hypertension may increase the levels of ACE- |$2$|⁠ , although there are claims that such medications actually reduce lung injury caused by COVID- |$19$|⁠. We employed bioinformatics and systematic approaches to identify such genetic links, using messenger RNA data peripheral blood cells from COVID- |$19$| patients and compared them with blood samples from patients with either chronic heart failure disease or hypertensive diseases. We have also considered the immune response genes with elevated expression in COVID- |$19$| to those active in cardiovascular diseases and hypertension. Differentially expressed genes (DEGs) common to COVID- |$19$| and chronic heart failure, and common to COVID- |$19$| and hypertension, were identified; the involvement of these common genes in the signalling pathways and ontologies studied. COVID- |$19$| does not share a large number of differentially expressed genes with the conditions under consideration. However, those that were identified included genes playing roles in T cell functions, toll-like receptor pathways, cytokines, chemokines, cell stress, type 2 diabetes and gastric cancer. We also identified protein–protein interactions, gene regulatory networks and suggested drug and chemical compound interactions using the differentially expressed genes. The result of this study may help in identifying significant targets of treatment that can combat the ongoing pandemic due to SARS-CoV- |$2$| infection. [ABSTRACT FROM AUTHOR]

Aims: To determine whether initiation of treatment with angiotensin converting enzyme inhibitors or angiotensin II receptor blockers (ACEI/ARBs) is associated with a subsequent reduction in haemoglobin in the general population. Methods: We undertook a national cohort study over a 13‐year period (2004–2016), using routine primary healthcare data from the UK Clinical Practice Research Datalink. We compared ACEI/ARB initiation with calcium channel blocker (CCB) initiation, to minimise confounding by indication. We included all first ACEI/ARB or CCB prescriptions in adults with at least 1 haemoglobin result in the 12 months before and 6 months after drug initiation. Our primary outcome was a ≥1 g/dL haemoglobin reduction in the 6 months after drug initiation. Results: We examined 146 610 drug initiation events in 136 655 patients. Haemoglobin fell by ≥1 g/dL after drug initiation in 19.5% (16 936/86 652) of ACEI/ARB initiators and 15.9% (9521/59 958) of CCB initiators. The adjusted odds ratio of a ≥1 g/dL haemoglobin reduction in ACEI/ARB initiators vs CCB initiators was 1.15 (95% confidence interval 1.12–1.19). Conclusion: ACEI/ARBs are associated with a modest increase in the risk of a haemoglobin reduction. For every 100 patients in our study that initiated a CCB, 16 experienced a ≥1 g/dL haemoglobin decline. If the effect is causal, 3 additional patients would have experienced this outcome if they had received an ACEI/ARB. This may have implications for drug choice and monitoring for many patients in primary care. Further research could identify patients at higher risk of this outcome, who may benefit from closer monitoring. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) patients with pre-existing cardiovascular disease (CVD) or with cardiovascular complications have a higher risk of mortality. The main cardiovascular complications of COVID-19 include acute cardiac injury, acute myocardial infarction (AMI), myocarditis, arrhythmia, heart failure, shock, and venous thromboembolism (VTE)/pulmonary embolism (PE). COVID-19 can cause cardiovascular complications or deterioration of coexisting CVD through direct or indirect mechanisms, including viral toxicity, dysregulation of the renin–angiotensin–aldosterone system (RAAS), endothelial cell damage and thromboinflammation, cytokine storm, and oxygen supply–demand mismatch. We systematically review cardiovascular manifestations, histopathology, and mechanisms of COVID-19, to help to formulate future research goals and facilitate the development of therapeutic management strategies. [ABSTRACT FROM AUTHOR]

Systemic arterial hypertension (referred to as hypertension herein) is a major risk factor of mortality worldwide, and its importance is further emphasized in the context of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection referred to as COVID-19. Patients with severe COVID-19 infections commonly are older and have a history of hypertension. Almost 75% of patients who have died in the pandemic in Italy had hypertension. This raised multiple questions regarding a more severe course of COVID-19 in relation to hypertension itself as well as its treatment with renin–angiotensin system (RAS) blockers, e.g. angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs). We provide a critical review on the relationship of hypertension, RAS, and risk of lung injury. We demonstrate lack of sound evidence that hypertension per se is an independent risk factor for COVID-19. Interestingly, ACEIs and ARBs may be associated with lower incidence and/or improved outcome in patients with lower respiratory tract infections. We also review in detail the molecular mechanisms linking the RAS to lung damage and the potential clinical impact of treatment with RAS blockers in patients with COVID-19 and a high cardiovascular and renal risk. This is related to the role of angiotensin-converting enzyme 2 (ACE2) for SARS-CoV-2 entry into cells, and expression of ACE2 in the lung, cardiovascular system, kidney, and other tissues. In summary, a critical review of available evidence does not support a deleterious effect of RAS blockers in COVID-19 infections. Therefore, there is currently no reason to discontinue RAS blockers in stable patients facing the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

Hypertension (HTN) is a primary risk factor for cardiovascular (CV) events, target organ damage (TOD), premature death and disability worldwide. The pathophysiology of HTN is complex and influenced by many factors including biological sex. Studies show that the prevalence of HTN is higher among adults aged 60 and over, highlighting the increase of HTN after menopause in women. Estrogen (E2) plays an important role in the development of systemic HTN and TOD, exerting several modulatory effects. The influence of E2 leads to alterations in mechanisms regulating the sympathetic nervous system, renin-angiotensin-aldosterone system, body mass, oxidative stress, endothelial function and salt sensitivity; all associated with a crucial inflammatory state and influenced by genetic factors, ultimately resulting in cardiac, vascular and renal damage in HTN. In the present article, we discuss the role of E2 in mechanisms accounting for the development of HTN and TOD in a sex-specific manner. The identification of targets with therapeutic potential would contribute to the development of more efficient treatments according to individual needs. [ABSTRACT FROM AUTHOR]

Patients with chronic kidney disease are at increased risk of cardiovascular disease and this often manifests clinically like heart failure. Conversely, patients with heart failure frequently have reduced kidney function. The links between the kidneys and cardiovascular system are being elucidated, with blood pressure being a key risk factor. Patients with heart failure have benefitted from many trials which have now established a strong evidence based on which to base management. However, patients with advanced kidney disease have often been excluded from these trials. Nevertheless, there is little evidence that the benefits of such treatments are modified by the presence or absence of kidney disease, but more direct evidence among patients with advanced kidney disease is required. Neprilysin inhibition is the most recent treatment to be shown to improve outcomes among patients with heart failure. The UK HARP-III trial assessed whether neprilysin inhibition improved kidney function in the short- to medium-term and its effects on cardiovascular biomarkers. Although no effect (compared to irbesartan control) was found on kidney function, allocation to neprilysin inhibition (sacubitril/valsartan) did reduce cardiac biomarkers more than irbesartan, suggesting that this treatment might improve cardiovascular outcomes in this population. Larger clinical outcomes trials are needed to test this hypothesis. [ABSTRACT FROM AUTHOR]

Cardiovascular disease is now the leading cause of pregnancy-related deaths in the United States. Increasing maternal mortality in the United States underscores the importance of proper cardiovascular management. Significant physiological changes during pregnancy affect the heart's ability to respond to pathological processes such as hypertension and heart failure. These physiological changes further affect the pharmacokinetic and pharmacodynamic properties of cardiac medications. During pregnancy, these changes can significantly alter medication efficacy and metabolism. This article systematically reviews the literature on safety, efficacy, pharmacokinetics, and pharmacodynamics of cardiovascular drugs used for hypertension and heart failure during pregnancy and lactation. The 2017 American College of Cardiology/American Heart Association hypertension guidelines recommend transitioning pregnant patients to methyldopa, nifedipine, or labetalol. Heart failure medications, including beta-blockers, furosemide, and digoxin, are relatively safe and can be used effectively. Medications that block the renin angiotensin–aldosterone system have been shown to be beneficial in the general population; however, they are teratogenic and, therefore, contraindicated in pregnancy. Cardiovascular medications can also enter breast milk and, therefore, care must be taken when selecting drugs during the lactation period. A summary of the safety of drugs during pregnancy and lactation from an online resource, LactMed by the National Library of Medicine's TOXNET database, is included. High-risk pregnant patients with cardiovascular disease require a multispecialty team of doctors, including health care providers from obstetrics and gynecology, maternal fetal medicine, internal medicine, cardiovascular disease specialists, and specialized pharmacology expertise. [ABSTRACT FROM AUTHOR]

Inhibition of the renin-angiotensin system in early postnatal life is a potential therapeutic approach to prevent long-term cardiovascular and kidney diseases in individuals born small. We determined the long-term effects of juvenile losartan treatment on cardiovascular and kidney function in control male rat offspring and those exposed to uteroplacental insufficiency and born small. Bilateral uterine vessel ligation (Restricted) or sham (Control) surgery was performed in late gestation in Wistar Kyoto rats. At weaning, male offspring were randomly assigned to receive losartan in their drinking water or drinking water alone from 5 to 8 weeks of age, and followed to 26 weeks of age. Systolic blood pressure and kidney function were assessed throughout the study. Pressure myography was used to assess passive mechanical wall properties in mesenteric and femoral arteries from 26-week-old offspring. Losartan treatment for three weeks lowered systolic blood pressure in both Control and Restricted groups but this difference was not sustained after the cessation of treatment. Losartan, irrespective of birth weight, mildly increased renal tubulointerstitial fibrosis when assessed at 26 weeks of age. Mesenteric artery stiffness was increased by the early losartan treatment, and was associated with increased collagen and decreased elastin content. Losartan also exerted long-term increases in fat mass and decreases in skeletal muscle mass. In this study, untreated Restricted offspring did not develop hypertension, vascular dysfunction or kidney changes as anticipated. Regardless, we demonstrate that short-term losartan treatment in the juvenile period negatively affects postnatal growth, and kidney and vascular parameters in adulthood, irrespective of birth weight. The long-term effects of early-life losartan treatment warrant further consideration in settings where the potential benefits may outweigh the risks; i.e. when programmed adulthood diseases are apparent and in childhood cardiovascular and kidney diseases. [ABSTRACT FROM AUTHOR]

Oleanolic acid is known to possess beneficial effects on the regulation of the cardiovascular homeostasis. However, the exact nature of the role of oleanolic acid on the regulation of body fluid balance and blood pressure homeostasis and its mechanisms involved are not well defined. Experiments were performed to identify the effects of oleanolic acid on the renin-angiotensin system and cardiac natriuretic hormone (ANP) system, and also renal function and blood pressure in normotensive and renovascular hypertensive rats. The change in the plasma levels of hormones and the expressions of renin, angiotensin II receptors, ANP, natriuretic peptide receptor-C, M 2 muscarinic receptor and GIRK4 were determined in the kidney, heart and aorta. Oleanolic acid was administered orally for 1 or 3 weeks. Here, we found that oleanolic acid suppressed plasma levels of renin activity and aldosterone and intrarenal levels of renin and angiotensin II type 1 receptor expression and increased angiotensin II type 2 receptor in normotensive and hypertensive rats. Also, oleanolic acid increased plasma levels of ANP. Further, oleanolic acid suppressed angiotensin II type 1 receptor and natriuretic peptide receptor-C expression and increased angiotensin II type 2 receptor and ANP expression in the heart and aorta. Along with these changes, oleanolic acid accentuated urinary volume, electrolyte excretion and glomerular filtration rate in normotensive rats and suppressed arterial blood pressure in hypertensive rats. These findings suggest that beneficial effects of oleanolic acid on the cardiorenal system are closely associated with its roles on the renin-angiotensin system and cardiac natriuretic hormone system. [ABSTRACT FROM AUTHOR]

The mineralocorticoid receptor (MR) belongs to the steroid hormone receptor family and classically functions as a ligand-dependent transcription factor. It is involved in water-electrolyte homeostasis and blood pressure regulation but independent from these effects also furthers inflammation, fibrosis, hypertrophy and remodeling in cardiovascular tissues. Next to genomic effects, aldosterone elicits very rapid actions within minutes that do not require transcription or translation and that occur not only in classical MR epithelial target organs like kidney and colon but also in nonepithelial tissues like heart, vasculature and adipose tissue. Most of these effects can be mediated by classical MR and its crosstalk with different signaling cascades. Near the plasma membrane, the MR seems to be associated with caveolin and striatin as well as with receptor tyrosine kinases like EGFR, PDGFR and IGF1R and G proteincoupled receptors like AT1 and GPER1, which then mediate nongenomic aldosterone effects. GPER1 has also been named a putative novel MR. There is a close interaction and functional synergism between the genomic and the nongenomic signaling so that nongenomic signaling can lead to long-term effects and support genomic actions. Therefore, understanding nongenomic aldosterone/MR effects is of potential relevance for modulating genomic aldosterone effects and may provide additional targets for intervention. [ABSTRACT FROM AUTHOR]

Since the mineralocorticoid receptor (MR) was cloned 30 years ago, it has become clear that MR is expressed in extra-renal tissues, including the cardiovascular system, where it is expressed in all cells of the vasculature. Understanding the role of MR in the vasculature has been of particular interest as clinical trials show that MR antagonism improves cardiovascular outcomes out of proportion to changes in blood pressure. The last 30 years of research have demonstrated that MR is a functional hormone-activated transcription factor in vascular smooth muscle cells and endothelial cells. This review summarizes advances in our understanding of the role of vascular MR in regulating blood pressure and vascular function, and its contribution to vascular disease. Specifically, vascular MR contributes directly to blood pressure control and to vascular dysfunction and remodeling in response to hypertension, obesity and vascular injury. The literature is summarized with respect to the role of vascular MR in conditions including: pulmonary hypertension; cerebral vascular remodeling and stroke; vascular inflammation, atherosclerosis and myocardial infarction; acute kidney injury; and vascular pathology in the eye. Considerations regarding the impact of age and sex on the function of vascular MR are also described. Further investigation of the precise molecular mechanisms by which MR contributes to these processes will aid in the identification of novel therapeutic targets to reduce cardiovascular disease (CVD)-related morbidity and mortality. [ABSTRACT FROM AUTHOR]

Background: Heart failure with preserved ejection fraction (HFpEF) has close ties with hypertension, though risk factors to the development of HFpEF in hypertensive patients are not fully understood. Left ventricular hypertrophy (LVH) signifies the susceptibility toward diastolic heart dysfunction, and genetic determinants of LVH as a result may serve as risk predictors for HFpEF in hypertension. We investigated the role of three renin–angiotensin–aldosterone system (RAAS) gene polymorphisms in the development of LVH in hypertensive patients with a diagnosis of HFpEF. Methods: A total of 176 hypertensive patients with a diagnosis of HFpEF were divided to cases with LVH and controls without. rs4343 and rs4291 of angiotensin-converting enzyme (ACE) and rs5186 of angiotensin receptor type 1 were genotyped using PCR-RFLP method. Results: Genotypes and allele frequencies were significantly different between the case and control groups for rs4343 and rs4291, whereas no difference was observed for rs5186.Conclusion: Increased ACE activity explains the significant association of rs4343 and rs4291 polymorphisms with LVH in the carriers. Furthermore, findings support the pathophysiologic links between RAAS and increased LV mass in hypertension and suggest a genetic susceptibility to HFpEF. Such polymorphisms may serve as risk predictors of HFpEF in hypertensive patients. [ABSTRACT FROM AUTHOR]

Since angiotensin increases the expression of plasminogen activator inhibitor (PAI), mechanisms associated with an actively functioning renin-angiotensin-aldosterone system can be expected to be associated with increased PAI-1 expression. These mechanisms are present not only in common conditions resulting in glomerulosclerosis associated with aging, diabetes or genetic mutations, but also in autoimmune disease (like scleroderma and lupus), radiation injury, cyclosporine toxicity, allograft nephropathy and ureteral obstruction. While the renin-angiotensin-aldosterone system and growth factors, such as transforming growth factor-beta (TGF-β), are almost always part of the process, there are rare experimental observations of PAI- 1 expression without their interaction. Here we review the literature on PAI-1 and its role in vascular, fibrotic and oxidative injury as well as work suggesting potential areas of intervention in the pathogenesis of multiple disorders. [ABSTRACT FROM AUTHOR]

Weaning preeclamptic (PE) rats exhibit exaggerated endotoxic signs of hypotension and cardiac autonomic neuropathy. Considering the role of renin-angiotensin system (RAS) in maternal programming during PE, we investigated the hypothesis that gestational modulation of offensive (Angiotensin II, Ang II) and defensive (Ang 1–7) components of RAS alleviates cardiovascular hyperresponsiveness of weaning PE mothers to postpartum endotoxemia. PE was induced by treating pregnant rats with the nitric oxide synthase inhibitor L-NAME (50 mg/kg/day) for 7 consecutive days starting from gestational day 14. The PE-associated elevations in gestational systolic blood pressure and proteinuria were reduced after gestational treatment with Ang 1–7 (Ang II-derived vasodilator), losartan (AT1 receptor antagonist), pioglitazone (RAS modulator), or combined losartan/pioglitazone, with the latter therapy being the most effective. In weaning PE rats, the potentiated falls in mean arterial pressure and spectral index of cardiac sympathovagal balance (low frequency/high frequency ratio) caused by i.v. Lipopolysaccharides (LPS, 5 mg/kg) were attenuated by all therapies. Pioglitazone and Ang 1–7 were more effective in reversing increases and decreases in left ventricular contractility and isovolumic relaxation time constant, respectively, seen in endotoxic PE mothers. Immunohistochemically, cardiac Toll-like receptor 4 (TLR-4) expression was increased in endotoxic PE rats, and this effect was abrogated by Ang 1–7 or losartan/pioglitazone. The same treatments blunted the increased cardiac angiotensin converting enzyme (ACE) expression whereas ACE2 expression was altered by none of the intervening therapies. Overall, the mitigation of Ang II/ACE imbalances alleviates the sensitized cardiovascular and inflammatory actions of endotoxemia in weaning PE mothers. • Prenatal losartan/pioglitazone regimen reduces PE hypertension and proteinuria. • Endotoxic hypotension in PE rats is attenuated by Ang1-7 and RAS inhibitions. • Ang1-7 or RAS inhibition blunts endotoxic cardiac parasympathetic dominance. • Ang 1–7 normalizes PE/LPS-evoked tachycardia and diastolic dysfunction. • Cardiac TLR-4/ACE protein expressions are abrogated by Ang1-7 or RAS inhibition. [ABSTRACT FROM AUTHOR]

Background: Management trends in early chronic kidney disease (CKD) and their associations with clinical outcomes have not previously been reported. Methods: We evaluated incident (Stage G3A) CKD patients from an integrated health care system in 2004-06, 2007-09 and 2010-12 to determine adjusted trends in screening (urinary protein quantification), treatment [prescription for angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB), and statin] and nephrology referral. For the same time periods, adjusted rates for mortality, progression to Stage G4 CKD and hospitalization for myocardial infarction or heart failure were calculated and compared across time periods. Results: There were 728, 788 and 956 patients with incident CKD in 2004-06, 2007-09 and 2010-12, respectively. Adjusted rates of proteinuria quantification (31, 39 and 51 screens/100 person-years), statin prescription (53, 63 and 64 prescriptions/ 100 person-years) and nephrology referral (2, 3 and 5 referrals/100 person-years) all increased over time (P for trend <0.001 in all cases). ACEI/ARB prescription rates did not change (88, 83 and 80 prescriptions/100 person-years, P = 0.68). Adjusted death rates (7, 5 and 6 deaths/100 person-years), CKD progression (9, 10 and 7 progressors/100 person-years) and cardiovascular hospitalization (10, 8 and 9 hospitalizations per 100/person-years) did not change (P for trend >0.4 in all cases). Conclusion: In this integrated health care system, management of incident CKD over the past decade has intensified. [ABSTRACT FROM AUTHOR]

Heart failure (HF) imposes significant economic and public health burdens upon modern society. It is known that disturbances in neurohormonal status play an important role in the pathogenesis of HF. Therapeutics that antagonize selected neurohormonal pathways, specifically the renin-angiotensin-aldosterone and sympathetic nervous systems, have significantly improved patient outcomes in HF. Nevertheless, mortality remains high with about 50% of HF patients dying within five years of diagnosis thus mandating ongoing efforts to improve HF management. The discovery of short noncoding microRNAs (miRNAs) and our increasing understanding of their functions, has presented potential therapeutic applications in complex diseases, including HF. Results from several genome-wide miRNA studies have identified miRNAs differentially expressed in HF cohorts suggesting their possible involvement in the pathogenesis of HF and their potential as both biomarkers and as therapeutic targets. Unravelling the functional relevance of miRNAs within pathogenic pathways is a major challenge in cardiovascular research. In this article, we provide an overview of the role of miRNAs in the cardiovascular system. We highlight several HF-related miRNAs reported from selected cohorts and review their putative roles in neurohormonal signaling. [ABSTRACT FROM AUTHOR]

Genetic differences between ethnic populations affect susceptibility to disease and efficacy of drugs. This study examined and compared the prevalence of single nucleotide polymorphisms ( SNPs) in genes of the renin-angiotensin system ( RAS) in a desert community of Indigenous Australians and in non-Indigenous Australians. The polymorphisms were angiotensinogen, AGT G-217A (rs5049); AGT G+174A (rs4762); Angiotensin II type 1 receptor, AGTR1 A+1166C (rs5186); angiotensin converting enzyme, ACE A-240T (rs4291), ACE T-93C (rs4292); renin, REN T+1142C (rs5706). They were measured using allelic discrimination assays. The prevalence of REN T+1142C SNP was similar in the two populations; 99% were homozygous for the T allele. All other SNPs were differently distributed between the two populations ( P < 0.0001). In non-Indigenous Australians, the A allele at position 204 of ACE rs4291 was prevalent (61.8%) whereas in the Indigenous Australians the A allele was less prevalent (28%). For rs4292, the C allele had a prevalence of 37.9% in non-Indigenous Australians but in Indigenous Australians the prevalence was only 1%. No Indigenous individuals were homozygous for the C allele of AGTR1 (rs5186). Thus the prevalence of RAS SNPs in this Indigenous Australian desert community was different from non-Indigenous Australians as was the prevalence of cytokine SNPs (as shown in a previous study). These differences may affect susceptibility to chronic renal and cardiovascular disease and may alter the efficacy of drugs used to inhibit the RAS. These studies highlight the need to study the pharmacogenetics of drug absorption, distribution, metabolism and excretion in Indigenous Australians for safe prescribing guidelines. [ABSTRACT FROM AUTHOR]

Angiotensin-converting enzyme-2, or ACE2, is primarily a zinc-dependent peptidase and ectoenzyme expressed in numerous cell types and functioning as a counterbalance to ACE in the renin-angiotensin system. It was discovered 21 years ago more than 40 years after the discovery of ACE itself. Its primary physiological activity is believed to be in the conversion of angiotensin II to the vasodilatory angiotensin-(1−7) acting through the Mas receptor. As such it has been implicated in numerous pathological conditions, largely in a protective mode which has led to the search for ACE2 activatory mechanisms. ACE2 has a diverse substrate specificity allowing its participation in multiple peptide pathways. It also regulates aspects of amino acid transport through its homology with a membrane protein, collectrin. It also serves as a viral receptor for the SARS virus, and subsequently SARS-CoV2, driving the current COVID-19 pandemic. ACE2 therefore provides a therapeutic target for the treatment of COVID and understanding the biological events following viral binding can provide insight into the multiple pathologies caused by the virus, particularly inflammatory and vascular. In part this may relate to the ability of ACE2, like ACE, to be shed from the cell membrane. The shed form of ACE2 (sACE2) may be a factor in determining susceptibility to certain COVID pathologies. Hence, for just over 20 years, ACE2 has provided numerous surprises in the field of vasoactive peptides with, no doubt, more to come but it is its central role in COVID pathology that is producing the current intense interest in its biology. [Display omitted] • ACE2 is a multi-functional enzyme primarily metabolising regulatory peptides. • ACE2 counterbalances the actions of ACE through conversion of Ang II to Ang-(1−7). • ACE2 participates in intestinal amino acid transport. • ACE2 is the receptor for some coronaviruses, especially SARS-CoV-2. • ACE2 provides a key therapeutic target in the prevention and treatment of COVID-19. [ABSTRACT FROM AUTHOR]

The renin–angiotensin system (RAS) is a major component of cardiovascular and renal homeostasis, maintaining blood pressure and water and electrolyte balance in health and disease. Whilst knowledge regarding the RAS in adult organisms has substantially increased over the last three decades, physiological effects and levels of functioning of the system during the perinatal period are poorly understood. It has been shown, however, that the RAS is subject to remarkable developmental changes that involve all system components, including the main active biologic peptide, angiotensin II (Ang II) and the receptors through which these effects are mediated, type 1 receptors (AT1Rs) and type 2 receptors (AT2Rs). The pattern of developmental changes suggests a relevant physiological role for the RAS in the critical cardio-renal adaptations to life after birth. In adulthood, the majority of the physiological functions of Ang II are mediated by activation of AT1Rs, whilst the roles for AT2Rs are less clear. Although the integrity of the AT1R signalling pathway is a pre-requisite for normal renal development, the physiological effects mediated by A1TRs during ontogeny are not well characterized. Much less is known regarding the roles that AT2Rs may play in regulating cardio-renal homeostasis in the newborn, despite the fact that the RAS appears to be a major player in fetal programming of disease. This article reviews current knowledge regarding the temporal and spatial expression pattern of ATRs during ontogeny, the cardiovascular and renal effects mediated by the ATRs early in life, as well as the clinical relevance for ATRs in the newborn period. [ABSTRACT FROM AUTHOR]

Background: The renin angiotensin aldosterone system (RAAS) plays a vital role in regulating glucose metabolism and blood pressure, electrolyte and fluid homeostasis. The aim of this systematic review is to assess the association of the RAAS genes with diabetes mellitus (DM) and its complications of retinopathy, neuropathy and cardiovascular disease (CVD). Materials and Methods: The relevant English-language studies were identified using the key words of DM, type 1 diabetes mellitus (T1DM), T2DM, renin angiotensin aldosterone polymorphisms or genotypes and RAAS from the search engines of MEDLINE/PubMed, and Scopus from January 1, 1995 to July 30, 2014. Inclusion criteria for selecting relevant studies were reporting the role of RAAS gene variants in the pathogenesis of T1DM or T2DM, diabetic retinopathy (DR), diabetic neuropathy and cardiovascular complication of DM. Results: The reviewers identified 204 studies of which 73 were eligible for inclusion in the present systematic review. The review indicates the angiotensinogen (AGT) M235T polymorphism might not affect the risk of DM. The role of angiotensin converting enzyme insertion/ deletion (ACE I/D) and angiotensin II type 1 receptor gene (AT1R) A1166C polymorphisms in the pathogenesis of DM could not be established. Studies indicate the absence of an association between three polymorphisms of AGT M235T, ACE I/D and AT1R A1166C and DR in DM patients. A protective role for ACE II genotype against diabetic peripheral neuropathy has been suggested. Also, the ACE I/D polymorphism might be associated with the risk of CVD in DM patients. Conclusion: More studies with adequate sample size that investigate the influence of all RAAS gene variants together on the risk of DM and its complications are necessary to provide a more clear picture of the RAAS genes polymorphisms involvement in the pathogenesis of DM and its complications. [ABSTRACT FROM AUTHOR]

This study aimed to elucidate the roles of both angiotensin II (ANG II) receptors - type 1 (AT1Rs) and type 2 (AT2Rs) - separately and together in influencing hemodynamic effects of endogenously produced nitric oxide (NO) during postnatal development. In conscious, chronically instrumented lambs aged ~1 week (8 ± 1 days, N = 8) and ~6 weeks (41 ± 2 days, N = 8), systolic, diastolic, and mean arterial pressure (SAP, DAP, MAP) and venous pressure (MVP), renal blood flow (RBF), and renal vascular resistance (RVR) were measured in response to the l-arginine analog, l-NAME after pretreatment with either the AT1R antagonist, ZD 7155, the AT2R antagonist, PD 123319, or both antagonists. The increase in SAP, DAP, and MAP by l-NAME was not altered by either ATR antagonist in either age group. The increase in RBF after l-NAME was, however, altered by both ATR antagonists in an age-dependent manner, which was mediated predominantly through AT2Rs in newborn lambs. These findings reveal that there is an age-dependent interaction between the renin-angiotensin (RAS) and the NO pathway in regulating renal but not systemic hemodynamics through both ATRs, whereas AT2Rs appear to be important in the renal hemodynamic effects of NO early in life. [ABSTRACT FROM AUTHOR]

The (pro)renin-renin receptor, (P)RR has been claimed to be a novel element of the renin-angiotensin system (RAS). The function of (P)RR has been widely studied in renal and vascular pathology but the cardio-specific function of (P)RR has not been studied in detail. We therefore generated a transgenic mouse (Tg) with cardio-restricted (P)RR overexpression driven by the alpha-MHC promotor. The mRNA expression of (P)RR was ∼170-fold higher (P<0.001) and protein expression ∼5-fold higher (P<0.001) in hearts of Tg mice as compared to non-transgenic (wild type, Wt) littermates. This level of overexpression was not associated with spontaneous cardiac morphological or functional abnormalities in Tg mice. To assess whether (P)RR could play a role in cardiac hypertrophy, we infused ISO for 28 days, but this caused an equal degree of cardiac hypertrophy and fibrosis in Wt and Tg mice. In addition, ischemia-reperfusion injury was performed in Langendorff perfused isolated mouse hearts. We did not observe differences in parameters of cardiac function or damage between Wt and Tg mouse hearts under these conditions. Finally, we explored whether the hypoxia sensing response would be modulated by (P)RR using HeLa cells with and without (P)RR overexpression. We did not establish any effect of (P)RR on expression of genes associated with the hypoxic response. These results demonstrate that cardio-specific overexpression of (P)RR does not provoke phenotypical differences in the heart, and does not affect the hearts’ response to stress and injury. It is concluded that increased myocardial (P)RR expression is unlikely to have a major role in pathological cardiac remodeling. [ABSTRACT FROM AUTHOR]

Background: Arterial and venous thrombosis may share common pathophysiology involving the activation of platelets and inflammatory mediators. A growing body of evidence suggests prothrombotic effect of renin angiotensin system (RAS) including vascular inflammation and platelet activation. We hypothesized that the use of angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) plays a role in protecting against venous thromboembolism (VTE) in patients atherosclerosis. Methods: We conducted a retrospective study, reviewing 1,100 consecutive patients admitted to a teaching hospital with a diagnosis of either myocardial infarction or ischemic stroke from 2005 to 2010. Patients who had been treated with anticoagulation therapy before or after the first visit were excluded. The occurrence of VTE during the follow up period, risk factors for VTE on admission, and the use of ACEIs or ARBs during the follow up period were recorded. Results: The mean age of the entire study population was 68.1 years. 52.0% of the patients were female and 76.5% were African American. 67.3% were on RAS inhibitorsThe overall incidence of VTE was 9.7% (n = 107). Among the RAS inhibitor users, the incidence of VTE events was 9.0% (54/603) for the ACEI only users, 7.1% (8/113) for the ARB only users, and 0% (0/24) for the patients taking combination of ACEI and ARB. Among patients on RAS inhibitors, 8.4% (62/740) developed a VTE, compared with 12.5% (45/360) in the nonuser group [HR (hazard ratio), 0.58; 95% CI (confidence interval), 0.39–0.84; P<0.01]. Even after controlling for factors related to VTE (smoking, history of cancer, and immobilization, hormone use) and diabetes, the use of RAS inhibitors was still associated with a significantly lower risk of developing VTE (AHR, 0.59; 95% CI, 0.40–0.88; P = 0.01). Conclusions: The use of RAS inhibitors appears to be associated with a reduction in the risk of VTE. [ABSTRACT FROM AUTHOR]

While preventing AKI is not always feasible (in part because many patients present to the hospital with ongoing AKI), mitigating its consequences is within closer reach, with blockade of the renin-angiotensin-aldosterone system (RAAS) after AKI appearing to be one of the most promising approaches. The authors reported a similar risk of AKI in the year following discharge of patients with AKI and treated with ACEi/ARB or not treated. Hsu CY, Liu KD, Yang J, et al: Renin-angiotensin system blockade after acute kidney injury (AKI) and risk of recurrent AKI. [Extracted from the article]

Background: Aliskiren is a novel renin-angiotensin aldosterone system (RAAS) inhibitor, the combination therapy of aliskiren and amlodipine for blood pressure control have been reported recently. The primary objective of this analysis is to review recently reported randomized controlled trials (RCTs) to compare antihypertensive effects and adverse events between mono (amlodipine or aliskiren alone) and combination therapy of both medicines. Methods: Databases for the search included Pubmed, Embase and the Cochrane Central Register of Controlled Trials. Revman v5.0 statistical program was used to analyze the data. Weighted mean differences (WMD) with a 95% confidence interval (CI) were used for the calculation of continuous data, and relative risk (RR) with a 95% CI was used for dichotomous data. Results: We analyzed the data from 7 RCTs for a total of 6074 participants in this meta-analysis. We found that the aliskiren/amlodipine combination therapy had a stronger effect in lowering blood pressure as compared with the monotherapy using aliskiren (SBP: WMD = −10.42, 95% CI −13.03∼−7.82, P<0.00001; DBP: WMD = −6.60, 95% CI −7.22∼−5.97, P<0.00001) or amlodipine (SBP: WMD = −4.85, 95% CI −6.88∼−2.81, P<0.00001; DBP: WMD = −2.91, 95% CI −3.85∼−1.97, P<0.00001). No differences were found in terms of adverse events between combination therapy and monotherapy, except for the rates of peripheral edema and hypokalaemia which were significantly lower in the combination therapy than in the amlodipine monotherapy (RR = 0.78, 0.66∼0.92, P = 0.004; RR = 0.51, 0.27∼0.97, P = 0.04). Similar antihypertensive effects were found in both obese (body mass index > = 30 kg/m2) hypertensive and non-obese (body mass index <30 kg/m2) hypertensive patients. Moreover, there was no difference with the blood pressure lowering or adverse effects with regards to the combination therapy in both subgroups. Conclusion: We found that aliskiren/amlodipine combination therapy provided a more effective blood pressure reduction than monotherapy with either drug without increase in the occurrence of adverse events. [ABSTRACT FROM AUTHOR]

Background: Patients with type 1 diabetes mellitus (DM) and renal hyperfiltration also exhibit systemic microvascular abnormalities, including endothelial dysfunction. The effect of renal hyperfiltration on systemic blood pressure (BP) is less clear. We therefore measured BP, renal hemodynamic function and circulating renin angiotensin aldosterone system (RAAS) mediators in type 1 DM patients with hyperfiltration (n = 36, DM-H, GFR≥135 ml/min/1.73 m2) or normofiltration (n = 40, DM-N), and 56 healthy controls (HC). Since renal hyperfiltration represents a state of intrarenal RAAS activation, we hypothesized that hyperfiltration would be associated with higher BP and elevated levels of circulating RAAS mediators. Methods: BP, glomerular filtration rate (GFR - inulin), effective renal plasma flow (paraaminohippurate) and circulating RAAS components were measured in DM-H, DM-N and HC during clamped euglycemia (4–6 mmol/L). Studies were repeated in DM-H and DM-N during clamped hyperglycemia (9–11 mmol/L). Results: Baseline GFR was elevated in DM-H vs. DM-N and HC (167±6 vs. 115±2 and 115±2 ml/min/1.73 m2, p<0.0001). Baseline systolic BP (SBP, 117±2 vs. 111±2 vs. 109±1, p = 0.004) and heart rate (76±1 vs. 67±1 vs. 61±1, p<0.0001) were higher in DM-H vs. DM-N and HC. Despite higher SBP in DM-H, plasma aldosterone was lower in DM-H vs. DM-N and HC (42±5 vs. 86±14 vs. 276±41 ng/dl, p = 0.01). GFR (p<0.0001) and SBP (p<0.0001) increased during hyperglycemia in DM-N but not in DM-H. Conclusions: DM-H was associated with higher heart rate and SBP values and an exaggerated suppression of systemic aldosterone. Future work should focus on the mechanisms that explain this paradox in diabetes of renal hyperfiltration coupled with systemic RAAS suppression. [ABSTRACT FROM AUTHOR]

Renin-angiotensin system (RAS) is a powerful modulator of renal hemodynamic and fluid homeostasis. Up-regulation in components of intra-renal RAS occurs with ageing. Recently we reported that 2 year old uninephrectomised (uni-x) female sheep have low renin hypertension and reduced renal function. By 5 years of age, these uni-x sheep had augmented decrease in renal blood flow (RBF) compared to sham. We hypothesised that this decrease in RBF in 5 year old uni-x sheep was due to an up-regulation in components of the intra-renal RAS. In this study, renal responses to angiotensin II (AngII) infusion and AngII type 1 receptor (AT1R) blockade were examined in the same 5 year old sheep. We also administered AngII in the presence of losartan to increase AngII bioavailability to the AT2R in order to understand AT2R contribution to renal function in this model. Uni-x animals had significantly lower renal cortical content of renin, AngII (∼40%) and Ang 1–7 (∼60%) and reduced cortical expression of AT1R gene than sham animals. In response to both AngII infusion and AT1R blockade via losartan, renal hemodynamic responses and tubular sodium excretion were significantly attenuated in uni-x animals compared to sham. However, AngII infusion in the presence of losartan caused ∼33% increase in RBF in uni-x sheep compared to ∼14% in sham (P<0.05). This was associated with a significant decrease in renal vascular resistance in the uni-x animals (22% vs 15%, P<0.05) without any changes in systemic blood pressure. The present study shows that majority of the intra-renal RAS components are suppressed in this model of low renin hypertension. However, increasing the availability of AngII to AT2R by AT1R blockade improved renal blood flow in uni-x sheep. This suggests that manipulation of the AT2R maybe a potential therapeutic target for treatment of renal dysfunction associated with a congenital nephron deficit. [ABSTRACT FROM AUTHOR]

The renin-angiotensin system is involved in multiple conditions ranging from cardiovascular disorders to cancer. Components of the pathway, including ACE, renin and angiotensin receptors are targets for disease treatment. This study addresses three receptors of the pathway: AT1, AT2, and MAS and how the receptors are similar and differ in activation by angiotensin peptides. Combining biochemical and amino acid variation data with multiple species sequence alignments, structural models, and docking site predictions allows for visualization of how angiotensin peptides may bind and activate the receptors; allowing identification of conserved and variant mechanisms in the receptors. MAS differs from AT1 favoring Ang-(1–7) and not Ang II binding, while AT2 recently has been suggested to preferentially bind Ang III. A new model of Ang peptide binding to AT1 and AT2 is proposed that correlates data from site directed mutagenesis and photolabled experiments that were previously considered conflicting. Ang II binds AT1 and AT2 through a conserved initial binding mode involving amino acids 111 (consensus 325) of AT1 (Asn) interacting with Tyr (4) of Ang II and 199 and 256 (consensus 512 and 621, a Lys and His respectively) interacting with Phe (8) of Ang II. In MAS these sites are not conserved, leading to differential binding and activation by Ang-(1–7). In both AT1 and AT2, the Ang II peptide may internalize through Phe (8) of Ang II propagating through the receptors’ conserved aromatic amino acids to the final photolabled positioning relative to either AT1 (amino acid 294, Asn, consensus 725) or AT2 (138, Leu, consensus 336). Understanding receptor activation provides valuable information for drug design and identification of other receptors that can potentially bind Ang peptides. [ABSTRACT FROM AUTHOR]

To analyze the long-term effects of early overfeeding on the heart and coronary circulation, the effect of ischemia-reperfusion (I/R) and the role of the renin-angiotensin system (RAS) was studied in isolated hearts from control and overfed rats during lactation. On the day of birth litters were adjusted to twelve pups per mother (controls) or to three pups per mother (overfed). At 5 months of age, the rats from reduced litters showed higher body weight and body fat than the controls. The hearts from these rats were perfused in a Langendorff system and subjected to 30 min of ischemia followed by 15 min of reperfusion (I/R). The myocardial contractility (dP/dt) and the coronary vasoconstriction to angiotensin II were lower, and the expression of the apoptotic marker was higher, in the hearts from overfed rats compared to controls. I/R reduced the myocardial contractily, the coronary vasoconstriction to angiotensin II and the vasodilatation to bradykinin, and increased the expression of (pro)renin receptor and of apoptotic and antiapoptotic markers, in both experimental groups. I/R also increased the expression of angiotensinogen in control but not in overfed rats. In summary, the results of this study suggest that early overnutrition induces reduced activity of the RAS and impairment of myocardial and coronary function in adult life, due to increased apoptosis. Ischemia-reperfusion produced myocardial and coronary impairment and apoptosis, which may be related to activation of RAS in control but not in overfed rats, and there may be protective mechanisms in both experimental groups. [ABSTRACT FROM AUTHOR]

Dysfunction of brain renin-angiotensin system (RAS) components is implicated in the development of hypertension. We previously showed that angiotensin (Ang) II-induced hypertension is mediated by increased production of proinflammatory cytokines (PIC), including tumor necrosis factor (TNF), in brain cardiovascular regulatory centers such as the paraventricular nucleus (PVN). Presently, we tested the hypothesis that central TNF blockade prevents dysregulation of brain RAS components and attenuates Ang II-induced hypertension. Male Sprague-Dawley rats were implanted with radio-telemetry transmitters to measure mean arterial pressure (MAP) and subjected to intracerebroventricular (ICV) infusion of etanercept (10 µg/kg/day) with/without concurrent subcutaneous 4-week Ang II (200 ng/kg/min) infusion. Chronic Ang II infusion resulted in a significant increase in MAP and cardiac hypertrophy, which was attenuated by inhibition of brain TNF with etanercept. Etanercept treatment also attenuated Ang II-induced increases in PIC and decreases in IL-10 expression in the PVN. Additionally, Ang II infusion increased expression of pro-hypertensive RAS components (ACE and AT1R), while decreasing anti-hypertensive RAS components (ACE2, Mas, and AT2 receptors), within the PVN. ICV etanercept treatment reversed these changes. Ang II-infusion was associated with increased oxidative stress as indicated by increased NAD(P)H oxidase activity and super oxide production in the PVN, which was prevented by inhibition of TNF. Moreover, brain targeted TNF blockade significantly reduced Ang II-induced NOX-2 and NOX-4 mRNA and protein expression in the PVN. These findings suggest that chronic TNF blockade in the brain protects rats against Ang II-dependent hypertension and cardiac hypertrophy by restoring the balance between pro- and anti-hypertensive RAS axes and inhibiting PIC and oxidative stress genes and proteins in the PVN. [ABSTRACT FROM AUTHOR]

Transient activation of the renin-angiotensin system (RAS) induces irreversible renal damage causing sustained elevation in blood pressure (BP) in Cyp1a1-Ren2 transgenic rats. In our current study we hypothesized that activation of the AT1-receptor (AT1R) leads to a T-cell response causing irreversible impairment of renal function and hypertension. Cyp1a1-Ren2 rats harbor a construct for activation of the RAS by indole-3-carbinol (I3C). Rats were fed a I3C diet between 4–8 weeks of age to induce hypertension. Next, I3C was withdrawn and rats were followed-up for another 12 weeks. Additional groups received losartan (20 mg/kg/day) or hydralazine (100 mg/kg/day) treatment between 4–8 weeks. Rats were placed for 24h in metabolic cages before determining BP at week 8, 12 and 20. At these ages, subsets of animals were sacrificed and the presence of kidney T-cell subpopulations was investigated by immunohistochemistry and molecular marker analysis. The development of sustained hypertension was completely prevented by losartan, whereas hydralazine only caused a partial decrease in BP. Markers of renal damage: KIM-1 and osteopontin were highly expressed in urine and kidney samples of I3C-treated rats, even until 20 weeks of age. Additionally, renal expression of regulatory-T cells (Tregs) was highly increased in I3C-treated rats, whereas the expression of T-helper 1 (Th1) cells demonstrated a strong decrease. Losartan prevented these effects completely, whereas hydralazine was unable to affect these changes. In young Cyp1a1-Ren2 rats AT1R activation leads to induction of an immune response, causing a shift from Th1-cells to Tregs, contributing to the development of irreversible renal damage and hypertension. [ABSTRACT FROM AUTHOR]

Background: Obesity during childhood has dramatically increased worldwide in the last decades. Environmental factors acting early in life, including nutrition, play an important role in the pathogenesis of obesity and cardiovascular diseases in adulthood. Aims: To analyze the effects of early overfeeding on the heart and coronary circulation, the effect of ischemia-reperfusion (I/R) and the role of the renin-angiotensin system (RAS) were studied in isolated hearts from control and overfed rats during lactation. Methods and Results: On the day of birth litters were adjusted to twelve pups per mother (control) or to three pups per mother (overfed). At weaning (21 days) the rats were killed and the heart perfused in a Langendorff system and subjected to 30 min of ischemia followed by 15 min of reperfusion. The contractility (left developed intraventricular pressure) was lower in the hearts from overfed rats, and was reduced by I/R in hearts from control but not from overfed rats. I/R also reduced the coronary vasoconstriction to angiotensin II more in hearts from control than from overfed rats, and the vasodilatation to bradykinin similarly in both experimental groups. The expression of both angiotensin AGTRa and AGTR2 receptors was increased in the myocardium of overfed rats, and I/R increased the expression of both receptors in control rats but reduced it in overfed rats. The expression of apoptotic and antiapoptotic markers was increased in hearts of overfed rats compared with control, and further increased by I/R. Conclusions: These results suggest that both overfeeding and I/R impair cardiac and coronary function due, at least in part, to activation of the angiotensin pathway. However, overfeeding may reduce the impairment of ventricular contractility by I/R. [ABSTRACT FROM AUTHOR]

Two (pro)renin receptors have been characterized so far, the mannose-6-phosphate receptor (M6P-R) and a specific receptor called (P)RR for ( pro) renin receptor. Each receptor controls a different aspect of renin and prorenin metabolism. The M6P-R is a clearance receptor, whereas (P)RR mediates their cellular effects by activating intracellular signaling and up-regulating gene expression. Moreover, binding to (P)RR increases renin enzymatic activity and fully activates prorenin, the inactive proenzyme form of renin. Experimental models suggest that increased (P)RR synthesis and/or activation may be relevant to diseases, especially to high blood pressure, to cardiac fibrosis associated with hypertension, and to diabetic nephropathy. [ABSTRACT FROM AUTHOR]

Abstract: Cardiovascular function is affected by many mechanisms, including the autonomic system, the kallikrein–kinin system (KKS), the renin–angiotensin system (RAS) and the endothelin system. The function of these systems seems to be fairly well preserved throughout the vertebrate scale, but evolution required several adaptations. Snakes are particularly interesting for studies related to the cardiovascular function because of their elongated shape, their wide variation in size and length, and because they had to adapt to extremely different habitats and gravitational influences. To keep the normal cardiovascular control the snakes developed anatomical and functional adaptations and interesting structural peculiarities are found in their autonomic, KKS, RAS and endothelin systems. Our laboratory has characterized some biochemical, pharmacological and physiological properties of these systems in South American snakes. This review compares the components and function of these systems in snakes and other vertebrates, and focuses on differences found in snakes, related with receptor or ligand structure and/or function in autonomic system, RAS and KKS, absence of components in KKS and the intriguing identity between a venom and a plasma component in the endothelin system. [Copyright &y& Elsevier]

Studies were conducted in rats to determine the effect of maternal diabetes and the consequent hyperglycemia on cardiovascular function in the offspring. Diabetes was induced in pregnant Wistar rats through streptozotocin injection (50 mg/kg). Cardiovascular parameters were measured in 2-mo-old offspring animals of diabetic (OD, n = 12) and control rats (OC, n = 8). Arterial pressure (AP), heart rate (HR), baroreflex sensitivity, and vascular responsiveness to phenylephrine (PH) and sodium nitroprusside (SN) were measured. Angiotensin-converting enzyme (ACE) activity in heart, kidney, and lung was determined. OD rats exhibited increases in systolic AP (138 ± 8 vs. 119 ± 6 mmHg, OD vs. OC), with no change in HR (342 ± 21 vs. 364 ± 39 beats per minute (bpm), OD vs. OC). The reflex tachycardia elicited by SN was reduced in OD rats, as indicated by the slope of the linear regression (-2.2 ± 0.4 vs. -3.6 ± 0.8 bpm/mmHg, OD vs. OC). Vascular responsiveness to PH was increased 63% in OD rats compared with OC. OD rats showed increases in ACE activity in heart, kidney, and lung (1.13 ± 0.24, 3.04 ± 0.86, 40.8 ± 8.9 vs. 0.73 ± 0.19, 1.7 ± 0.45, 28.1 ± 6 nmol His-Leu · min-1 mg protein-1, OD vs. OC). Results suggest that diabetes during pregnancy affects cardiovascular function in offspring, seen as hypertension, baroreflex dysfunction, and activation of tissue renin-angiotensin system. [ABSTRACT FROM AUTHOR]

Obesity is a chronic state of energy imbalance that represents a major public health problem and greatly increases the risk for developing hypertension, hyperglycemia, and a multitude of related pathologies that encompass the metabolic syndrome. The underlying mechanisms and optimal treatment strategies for obesity, however, are still not fully understood. The control of energy balance involves the actions of circulating hormones on a widely distributed network of brain regions involved in the regulation of food intake and energy expenditure, including the arcuate nucleus of the hypothalamus. While obesity is known to disrupt neurocircuits controlling energy balance, including those in the hypothalamic arcuate nucleus, the pharmacological targeting of these central mechanisms often produces adverse cardiovascular and other off-target effects. This highlights the critical need to identify new anti-obesity drugs that can activate central neurocircuits to induce weight loss without negatively impacting blood pressure control. The renin–angiotensin system may provide this ideal target, as recent studies show this hormonal system can engage neurocircuits originating in the arcuate nucleus to improve energy balance without elevating blood pressure in animal models. This review will summarize the current knowledge of renin–angiotensin system actions within the arcuate nucleus for control of energy balance, with a focus on emerging roles for angiotensin II, prorenin, and angiotensin-(1–7) pathways. [ABSTRACT FROM AUTHOR]

Evidence has arisen in recent years suggesting that a tissue renin-angiotensin system (tRAS) is involved in the progression of various human diseases. This system contains two regulatory pathways: a pathological pro-inflammatory pathway containing the Angiotensin Converting Enzyme (ACE)/Angiotensin II (AngII)/Angiotensin II receptor type 1 (AGTR1) axis and a protective anti-inflammatory pathway involving the Angiotensin II receptor type 2 (AGTR2)/ACE2/Ang1–7/MasReceptor axis. Numerous studies reported the positive effects of pathologic tRAS pathway inhibition and protective tRAS pathway stimulation on the treatment of cardiovascular, inflammatory, and autoimmune disease and the progression of neuropathic pain. Cell senescence and aging are known to be related to RAS pathways. Further, this system directly interacts with SARS-CoV 2 and seems to be an important target of interest in the COVID-19 pandemic. This review focuses on the involvement of tRAS in the progression of the mentioned diseases from an interdisciplinary clinical perspective and highlights therapeutic strategies that might be of major clinical importance in the future. [ABSTRACT FROM AUTHOR]

Angiotensin II (ANG II) is part of the renin-angiotensin system (RAS) in vertebrates and exert vasoconstriction in all species studied. The present study examines the vasopressor effect of ANG II in the ball python (Python regius), and examines whether ANG II exert its effect through direct angiotensin receptors or through an activation of α-adrenergic receptors. The studies were conducted in snakes with chronic arterial catheters that had recovered from anesthesia. In addition to demonstrating a clear and pronounced dose-dependent rise in arterial blood pressure upon repeated injections of boluses with ANG II (0.001–1 μg/kg), we demonstrate that the pressor response persisted following α-adrenergic blockade using the α-adrenergic antagonist phentolamine (2.5 mg/kg). Unfortunately, it proved impossible to block the ANG receptors using losartan (1, 3 or even 10 mg/kg). The pressor response to ANG II was associated with a significant rise in heart rate at the higher dosages, pointing to a resetting of the barostatic mechanism for heart rate regulation. The responses were similar in fasting and digesting pythons despite the expected rise in baseline values for blood pressure and heart rate of the digesting snakes. Image 1 • Angiotensin II exerts a pronounced vasopressor action in ball pythons (Python regius) with small effects on heart rate. • The effects of angiotensin II (ANG II) are not altered by blockade of the α-adrenergic receptors. • Angiotensin II (ANG II) elicited similar in responses in fasting and digesting snakes. • Losartan could not block the cardiovascular responses to ANG II in Python regius. [ABSTRACT FROM AUTHOR]

Genetic mapping of modifier loci affecting malignant hypertension in TGRm Ren2 rats. Background. Genetic background has a major influence on the manifestation of multifactorial diseases such as hypertension in which severe complications may be caused through an interaction with additional factors, which may be genetically determined. We have previously described a genetic model of malignant hypertension (MH) in rats carrying the mouse Ren2 gene (TGRmRen2 -27), in which the phenotype is dependent on the genetic background. Methods. Using a single homozygous TGRmRen2 -27 male as transgene donor, we produced two F1 populations with (a ) 100% penetrance of MH in progeny heterozygous for the Fischer F344 genetic background and (b ) 58.5% penetrance in progeny heterozygous for the Lewis genetic background. To identify the modifier loci affecting the phenotype, a cohort of 252 males was produced by breeding the same single male with Fischer-Lewis F1 females. The progeny were phenotyped for clinical and pathological features of MH. Results. Genome-wide screening and quantitative trait loci (QTL) analysis identified two loci, on chromosome 10 (LOD 4.4) and on chromosome 17 (LOD 3.9) close to the Ace and At1 genes, respectively, which contribute to the lethal MH phenotype. Their influence on mortality was consistent with a multiplicative effect of the two loci. In addition, we found higher plasma angiotensin-converting enzyme activity in progeny receiving the Fischer allele than in progeny receiving the Lewis allele (123.5 ± 9.5 vs. 91.8 ± 4.9 U/liter, P < 0.01), suggesting the association of angiotensin-converting enzyme and MH. Conclusions. Our study demonstrates the application of a transgene as a “major gene” to facilitate the identification of modifier loci, which can affect the phenotype of MH, and reveals Ace and At1 as candidate genes involved in the manifestation of the MH phenotype. [ABSTRACT FROM AUTHOR]