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This review examines the impact of obesity on the pathophysiology of heart failure with preserved ejection fraction (HFpEF) and focuses on novel mechanisms for HFpEF prevention using a glucagon-like peptide-1 receptor agonism (GLP-1 RA). Obesity can lead to HFpEF through various mechanisms, including low-grade systemic inflammation, adipocyte dysfunction, accumulation of visceral adipose tissue, and increased pericardial/epicardial adipose tissue (contributing to an increase in myocardial fat content and interstitial fibrosis). Glucagon-like peptide 1 (GLP-1) is an incretin hormone that is released from the enteroendocrine L-cells in the gut. GLP-1 reduces blood glucose levels by stimulating insulin synthesis, suppressing islet α-cell function, and promoting the proliferation and differentiation of β-cells. GLP-1 regulates gastric emptying and appetite, and GLP-1 RA is currently indicated for treating type 2 diabetes (T2D), obesity, and metabolic syndrome (MS). Recent evidence indicates that GLP-1 RA may play a significant role in preventing HFpEF in patients with obesity, MS, or obese T2D. This effect may be due to activating cardioprotective mechanisms (the endogenous counter-regulatory renin angiotensin system and the AMPK/mTOR pathway) and by inhibiting deleterious remodeling mechanisms (the PKA/RhoA/ROCK pathway, aldosterone levels, and microinflammation). However, there is still a need for further research to validate the impact of these mechanisms on humans.

Introduction: An increased risk of atrial fibrillation (AF) has been demonstrated in high-performance athletes. Soluble vascular adhesion molecule-1 (sVCAM-1), a biomarker involved in inflammation and cardiac remodeling, is associated with the development of AF in the general population. However, the relationship between sVCAM-1 and left atrial (LA) remodeling has been poorly investigated in long-distance runners (LDR). Aim: To determine the association between LA remodeling and sVCAM-1 levels in LDR during the training period before a marathon race. Methods: Thirty-six healthy male LDR (37.0 ± 5.3 years; 174.0 ± 7.0 height; BMI: 23.8 ± 2.8; V°O 2 -peak: 56.5 ± 7.3 mL·kg -1 ·min -1 ) were evaluated in this single-blind and cross-sectional study. The LDR were separated into two groups according to previous training levels: high-training (HT) ( n = 18) ≥100 km·week -1 and low-training (LT) ( n = 18) ≥70 and <100 km·week -1 . Also, 18 healthy non-active subjects were included as a control group (CTR). In all participants, transthoracic echocardiography was performed. sVCAM-1 blood levels were measured baseline and immediately finished the marathon race in LDR. Results: HT showed increased basal levels of sVCAM-1 (651 ± 350 vs. 440 ± 98 ng·mL -1 CTR, p = 0.002; and vs. 533 ± 133 ng·mL -1 LT; p = 0.003) and a post-marathon increase (ΔsVCAM-1) (651 ± 350 to 905 ± 373 ng·mL -1 ; p = 0.002), that did not occur in LT (533 ± 133 to 651 ± 138 ng·mL -1 ; p = 0.117). In LDR was a moderate correlation between LA volume and sVCAM-1 level (rho = 0.510; p = 0.001). Conclusions: In male long-distance runners, sVCAM-1 levels are directly associated with LA remodeling. Also, the training level is associated with basal sVCAM-1 levels and changes after an intense and prolonged exercise (42.2 km). Whether sVCAM-1 levels predict the risk of AF in runners remains to be established., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Contreras-Briceño, Herrera, Vega-Adauy, Salinas, Ocaranza, Jalil, Mandiola, García, Chiong, Castro, Lavandero and Gabrielli.)

Background: Thiazides are one of the most common antihypertensive drugs used for hypertension treatment and hydrochlorothiazide (HCTZ) is the most frequently used diuretic for hypertension treatment. The Rho/Rho-kinase (ROCK) path plays a key function in cardiovascular remodeling. We hypothesized that in preclinical hypertension HCTZ reduces myocardial ROCK activation and consequent myocardial remodeling., Methods: The preclinical model of deoxycorticosterone (DOCA)-salt hypertension was used (Sprague-Dawley male rats). After 3 weeks, in 3 different groups: HCTZ, the ROCK inhibitor fasudil or spironolactone was added (3 weeks). After 6 weeks myocardial hypertrophy and fibrosis, cardiac levels of profibrotic proteins, mRNA levels (RT PCR) of pro remodeling and pro oxidative molecules and ROCK activity were determined., Results: Blood pressure, myocardial hypertrophy and fibrosis were reduced significantly by HCTZ, fasudil and spironolactone. In the heart, increased levels of the pro-fibrotic proteins Col-I, Col-III and TGF-β1 and gene expression of pro-remodeling molecules TGF-β1, CTGF, MCP-1 and PAI-1 and the pro-oxidative molecules gp91phox and p22phox were significantly reduced by HCTZ, fasudil and spironolactone. ROCK activity in the myocardium was increased by 54% ( P < 0.05) as related to the sham group and HCTZ, spironolactone and fasudil, reduced ROCK activation to control levels., Conclusions: HCTZ reduced pathologic LVH by controlling blood pressure, hypertrophy and myocardial fibrosis and by decreasing myocardial ROCK activation, expression of pro remodeling, pro fibrotic and pro oxidative genes. In hypertension, the observed effects of HCTZ on the myocardium might explain preventive outcomes of thiazides in hypertension, specifically on LVH regression and incident heart failure.

This single-blind and cross-sectional study evaluated the role of Rho-kinase (ROCK) as a biomarker of the cardiovascular remodelling process assessed by echocardiography in competitive long-distance runners (LDRs) during the training period before a marathon race. Thirty-six healthy male LDRs (37.0 ± 5.3 years; 174.0 ± 7.0 height; BMI: 23.8 ± 2.8; V˙ O 2 -peak: 56.5 ± 7.3 mL·kg -1 ·min -1 ) were separated into two groups according to previous training level: high-training (HT, n = 16) ≥ 100 km·week -1 and low-training (LT, n = 20) ≥ 70 and < 100 km·week -1 . Also, twenty-one healthy nonactive subjects were included as a control group (CTR). A transthoracic echocardiography was performed and ROCK activity levels in circulating leukocytes were measured at rest (48 h without exercising) the week before the race. The HT group showed a higher left ventricular mass index (LVMi) and left atrial volume index (LAVi) than other groups ( p < 0.05, for both); also, higher levels of ROCK activity were found in LDRs (HT = 6.17 ± 1.41 vs. CTR = 1.64 ± 0.66 ( p < 0.01); vs. LT = 2.74 ± 0.84; ( p < 0.05)). In LDRs a direct correlation between ROCK activity levels and LVMi (r = 0.83; p < 0.001), and LAVi (r = 0.70; p < 0.001) were found. In conclusion, in male competitive long-distance runners, the load of exercise implicated in marathon training is associated with ROCK activity levels and the left cardiac remodelling process assessed by echocardiography.

Background: Reverse remodeling is a clinically relevant endpoint in heart failure with reduced ejection fraction (HFrEF). Rho-kinase (ROCK) signaling cascade activation correlates with cardiac remodeling and left ventricular (LV) systolic dysfunction in HFrEF patients. Cardiac resynchronization therapy (CRT) is effective in HFrEF, especially when there is a left bundle block, as this treatment may stimulate reverse remodeling, thereby improving quality of life and prolonging survival for patients with this severe condition. Here, we evaluate the hypothesis that ROCK activation is reduced after effective CRT in HFrEF. Methods: ROCK activation in circulating leukocytes was evaluated in 28 HFrHF patients, using Western blot (myosin light chain phosphatase subunit 1 phosphorylation, MYPT1p/t), before and three months after initiation of CRT. LV systolic function and remodeling were assessed by echocardiography. Results: Three months after CRT, LV ejection fraction increased an average of 14.5% ( p < 0.001) in 13 patients (responders), while no change was observed in 15 patients (non-responders). End-systolic diameter decreased 16% ( p < 0.001) in responders, with no change in non-responders. ROCK activation in PBMCs decreased 66% in responders ( p < 0.05) but increased 10% in non-responders (NS). LV end-diastolic diameter was also 5.2 mm larger in non-responders vs. responders ( p = 0.058). LV ejection fraction, systolic diameter, and ROCK activation levels were similar in both groups at baseline. Conclusion: In HFrEF patients, 3 months of effective CRT induced reverse myocardial remodeling, and ROCK activation was significantly decreased in circulating leukocytes. Thus, decreased ROCK activation in circulating leukocytes may reflect reverse cardiac remodeling in patients with heart failure., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Ocaranza, Jalil, Altamirano, León, Moya, Lonis, Gabrielli, Nab, Córdova, Paredes, Vergara, Bittner, Sabat and Pastorini.)

The renin-angiotensin system, one of the main regulators of vascular function, controls vasoconstriction, inflammation and vascular remodeling. Antagonistic actions of the counter-regulatory renin-angiotensin system, which include vasodilation, anti-proliferative, anti-inflammatory and anti-remodeling effects, have also been described. However, little is known about the direct effects of angiotensin-(1-9), a peptide of the counter-regulatory renin-angiotensin system, on vascular smooth muscle cells. Here, we studied the anti-vascular remodeling effects of angiotensin-(1-9), with special focus on the control of vascular smooth muscle cell phenotype. Angiotensin-(1-9) decreased blood pressure and aorta media thickness in spontaneously hypertensive rats. Reduction of media thickness was associated with decreased vascular smooth muscle cell proliferation. In the A7r5 VSMC cell line and in primary cultures of rat aorta smooth muscle cells, angiotensin-(1-9) did not modify basal proliferation. However, angiotensin-(1-9) inhibited proliferation, migration and contractile protein decrease induced by platelet derived growth factor-BB. Moreover, angiotensin-(1-9) reduced Akt and FoxO1 phosphorylation at 30 min, followed by an increase of total FoxO1 protein content. Angiotensin-(1-9) effects were blocked by the AT2R antagonist PD123319, Akt-Myr overexpression and FoxO1 siRNA. These data suggest that angiotensin-(1-9) inhibits vascular smooth muscle cell dedifferentiation by an AT2R/Akt/FoxO1-dependent mechanism., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: The intracellular ROCK signaling pathway is an important modulator of blood pressure and of cardiovascular and renal remodeling when Rho-kinase activity is increased. Besides, in preclinical models of diabetes, ROCK activation has also a role in abnormal glucose metabolism as well as in subsequent vascular and myocardial dysfunction. In humans, there are a few data assessing ROCK activation in patients with type 2 diabetes mellitus (T2D) and no studies assessing upstream/downstream components of the ROCK pathway. We assessed here levels of ROCK activation and some of the RhoA/ROCK cascade molecules in peripheral blood mononuclear cells (PBMCs) in T2D patients under current treatment., Methods: Cross-sectional observational study comparing 28 T2D patients under current antidiabetic treatment with 31 consecutive healthy subjects, matched by age and gender. Circulating levels of malondialdehyde, angiotensin II and inflammatory cytokines IL-6 and IL-8 were determined in all subjects. ROCK activation in PMBCs, upstream and downstream cascade proteins, and levels of the proinflammatory molecules VCAM, ICAM-1 and IL-8 were determined in their PMBCs by Western blot., Results: Compared to healthy controls, ROCK activation in T2D patients measured by 2 direct ROCK targets in PBMCs was increased by 420 and 570% (p < 0001) and it correlated significantly with serum glucose levels. p38 MAPK phosphorylation (downstream from ROCK) and JAK-2 (upstream from ROCK) were significantly higher in the T2D patients by 580% and 220%, respectively. In T2D patients, significantly increased PBMC levels of the proinflammatory molecules VCAM-1, ICAM-1 and IL-8 were observed compared to control subjects (by 180%, 360% and 260%, respectively). Circulating levels of Ang II and MDA were significantly higher in T2D patients by 29 and 63%, respectively., Conclusions: T2D patients under treatment with glucose-lowering drugs, antihypertensive treatment as well as with statins have significantly increased ROCK activation in their circulating leukocytes along with higher phosphorylation of downstream cascade proteins despite pharmacologic treatment, along with increased plasma angiotensin II and MDA levels. ROCK inhibition might have an additional role in the prevention and treatment of T2D.

The renin-angiotensin system is an important component of the cardiovascular system. Mounting evidence suggests that the metabolic products of angiotensin I and II - initially thought to be biologically inactive - have key roles in cardiovascular physiology and pathophysiology. This non-canonical axis of the renin-angiotensin system consists of angiotensin 1-7, angiotensin 1-9, angiotensin-converting enzyme 2, the type 2 angiotensin II receptor (AT 2 R), the proto-oncogene Mas receptor and the Mas-related G protein-coupled receptor member D. Each of these components has been shown to counteract the effects of the classical renin-angiotensin system. This counter-regulatory renin-angiotensin system has a central role in the pathogenesis and development of various cardiovascular diseases and, therefore, represents a potential therapeutic target. In this Review, we provide the latest insights into the complexity and interplay of the components of the non-canonical renin-angiotensin system, and discuss the function and therapeutic potential of targeting this system to treat cardiovascular disease.

Background: Angiotensin II is a potent activator of the Rho-kinase (ROCK) pathway, through which it exerts some of its adverse vasoconstrictor effects. Clinical evidence on the effects of blocking the angiotensin II receptor 1 on ROCK activity in hypertensive patients is scarce., Objective: To demonstrate that ROCK activity in peripheral blood mononuclear cells (PMBCs) in patients with essential hypertension is reduced earlier than previously observed, along with blood pressure (BP) lowering on treatment with olmesartan., Methods: Prospective pilot open study; 17 hypertensive patients were treated with progressive olmesartan doses starting with 20 mg qd. BP was measured at 3, 6 and 9 weeks after treatment initiation. If treatment failed to normalize BP after 3 weeks, olmesartan dose was increased to 40 mg qd, and if still hypertensive after 6 weeks, 12.5 mg of hydrochlorothiazide qd was added. ROCK activity was measured at baseline and 9 weeks after treatment as myosin phosphatase target subunit 1 phosphorylation (MYPT1-p/T ratio) in PBMC., Results: Mean baseline BP was 162 ± 4.9/101 ± 2.4 mmHg. After 9 weeks of treatment, both systolic and diastolic BP were reduced by 41 and 22 mmHg, respectively (p<0.05). Mean pretreatment MYPT1- p/T ratio in PMBCs was significantly reduced by 80% after 9 weeks with olmesartan (p<0.01)., Conclusion: Normotension achieved after 9 weeks in 82% of the patients treated with olmesartan was associated with a significant reduction of ROCK activity in PBMC., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Increased Rho-kinase activity in circulating leucocytes is observed in heart failure with reduced ejection fraction (HFrEF). However, there is little information in HFrEF regarding other Rho-kinase pathway components an on the relationship between Rho-kinase and apoptosis. Here, Rho-kinase activation levels and phosphorylation of major downstream molecules and apoptosis levels were measured for the first time both in HFrEF patients and healthy individuals., Methods: Cross-sectional study comparing HFrEF patients (n = 20) and healthy controls (n = 19). Rho-kinase activity in circulating leucocytes (peripheral blood mononuclear cells, PBMCs) was determined by myosin light chain phosphatase 1 (MYPT1) and ezrin-radixin-moesin (ERM) phosphorylation. Rho-kinase cascade proteins phosphorylation p38-MAPK, myosin light chain-2, JAK and JNK were also analysed along with apoptosis., Results: MYPT1 and ERM phosphorylation were significantly elevated in HFrEF patients, (3.9- and 4.8-fold higher than in controls, respectively). JAK phosphorylation was significantly increased by 300% over controls. Phosphorylation of downstream molecules p38-MAPK and myosin light chain-2 was significantly higher by 360% and 490%, respectively, while JNK phosphorylation was reduced by 60%. Catecholamine and angiotensin II levels were significantly higher in HFrEF patients, while angiotensin-(1-9) levels were lower. Apoptosis in circulating leucocytes was significantly increased in HFrEF patients by 2.8-fold compared with controls and significantly correlated with Rho-kinase activation., Conclusion: Rho-kinase pathway is activated in PMBCs from HFrEF patients despite optimal treatment, and it is closely associated with neurohormonal activation and with apoptosis. ROCK cascade inhibition might induce clinical benefits in HFrEF patients, and its assessment in PMBCs could be useful to evaluate reverse remodelling and disease regression., (© 2019 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Introduction: The aim of this study was to assess whether apical lesions are associated with inflammatory serum markers of cardiovascular risk, especially high-sensitivity C-reactive protein (hsCRP), in young adults., Methods: In this cross-sectional study, otherwise healthy individuals with apical lesions of endodontic origin (ALEOs) and a clinical diagnosis of asymptomatic apical periodontitis and controls aged between 18 and 40 years were included. Patients' sociodemographic characteristics, medical history, and classic cardiovascular risk factors were recorded, and the pathobiological determinants of atherosclerosis in youth score was calculated. Oral clinical and radiographic examinations were performed. Blood samples were collected to determine the lipid profile, glycated hemoglobin, hsCRP, immunoglobulin G, interleukin (IL)-6, IL-10, IL-12p70, matrix metalloproteinase 8, soluble vascular cellular adhesion molecule-1, soluble intercellular adhesion molecule-1, and soluble E-selectin. Bivariate and multivariate analyses adjusting for oral and classic cardiovascular risk factors were performed., Results: hsCRP levels were significantly higher in ALEO patients versus controls (median = 2.54 vs 0.78), whereas the pathobiological determinants of atherosclerosis in youth score was comparable among the groups. Also, the levels of IL-6, matrix metalloproteinase 8, and soluble E-selectin were significantly higher in ALEO patients. hsCRP, IL-6, and IL-12 correlated with soluble adhesion molecules. Bivariate analysis based on hsCRP serum concentrations ≥1 mg/L showed an odds ratio (OR) = 6.8, and the risk increased 3.3 times for an additional ALEO. In multivariate analysis, ALEO was significantly associated with hsCRP levels ≥1 mg/L (OR = 5.1-12.8) independently of the adjustment model. ALEO also associated with CRP levels >3 mg/L, which was significant after the adjustment for covariates (OR = 4.0)., Conclusions: ALEO is associated with the systemic inflammatory burden and cardiovascular risk determined by hsCRP, supporting a mechanistic link for cardiovascular diseases in young adults., (Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Hypertension-induced cardiovascular and renal damage can be mediated by activation of the renin-angiotensin-aldosterone system. There are different factors beyond renin-angiotensin-aldosterone system involved in hypertension and renal damage. Inflammation has emerged as an important mediator of hypertension and cardiovascular and kidney damage. Angiotensin-(1-9), a peptide of the renin-angiotensin system, counter-regulates both the physiological and pathological actions of angiotensin II. Recent data has shown that angiotensin-(1-9) protects the heart and blood vessels from adverse cardiovascular remodeling in experimental models of hypertension and/or heart failure and reduces cardiac fibrosis in stroke-prone, spontaneously hypertensive rats. These effects are mediated by the angiotensin II type 2 receptor (AT2R). However, it remains unknown whether angiotensin-(1-9) also has an anti-inflammatory effect. In the present study, we investigate whether angiotensin-(1-9) reduces inflammation and fibrosis in the heart, arteries, and kidney in a DOCA-salt hypertensive model and explore the mechanisms underlying the amelioration of end-organ damage. DOCA-salt hypertensive rats received: a) vehicle, b) angiotensin-(1-9), c) PD123319 (AT2R blocker), d) angiotensin-(1-9) plus A779 (a Mas receptor blocker) or e) angiotensin-(1-9) plus PD123319, and sham rats were used as a control. Our results showed that angiotensin-(1-9) decreased hypertension and increased vasodilation in DOCA-salt hypertensive rats. These actions were partially inhibited by PD123319. Moreover, angiotensin-(1-9) decreased diuresis, fibrosis, and inflammation. These beneficial effects were not mediated by Mas or AT2R blockers. We concluded that angiotensin-(1-9) protects against volume overload-induced hypertensive cardiovascular and kidney damage by decreasing inflammation in the heart, aortic wall, and kidney, through mechanisms independent of the Mas or AT2R., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Angiotensin-(19), a peptide of the non-classical renin angiotensin system, has been shown to prevent and revert hypertension and cardiac hypertrophy. We hypothetized that systemic delivery of angiotensin-(1-9) following myocardial infarction will also be protective and extend to provide protection during reperfusion of the ischemic heart. Adult Sprague Dawley rats were subjected to left anterior descending artery ligation and treated with angiotensin-(1-9) via osmotic mini-pump for 2 weeks in the presence or absence of Mas receptor or AT 2 R antagonists (A779 and PD123319, respectively). Myocardial death and left ventricular function were evaluated after infarction. Infarct size and functional parameters were determined in isolated rat hearts after global ischemia/reperfusion in the presence of angiotensin-(1-9) plus receptor antagonists or Akt inhibitor at reperfusion. in vitro, neonatal rat ventricular cardiomyocytes underwent simulated ischemia/reperfusion and angiotensin-(1-9) was co-incubated with A779, PD123319 or Akt inhibitor. Systemic delivery of angiotensin-(1-9) significantly decreased cell death and improved left ventricular recovery after in vivo myocardial infarction. Perfusion with the peptide reduced the infarct size and improved functional recovery after ex vivo ischemia/reperfusion. In vitro, angiotensin-(1-9) decreased cell death in isolated neonatal rat ventricular cardiomyocytes subjected to simulated ischemia/reperfusion. The cardioprotective effects of angiotensin-(1-9) were blocked by PD123319 and Akti VIII but not by A779. Angiotensin-(1-9) limits reperfusion-induced cell death by an AT 2 R- and Aktdependent mechanism. Angiotensin-(1-9) is a novel strategy to protect against cardiac ischemia/reperfusion injury., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Rho-kinase has relevant functions in blood pressure modulation and cardiovascular remodeling. Rho-kinase activity is determined in circulating leukocytes measuring phosphorylation of its target myosin phosphatase target subunit 1 (MYPT1), but its relationship with Rho-kinase activity in the myocardium and in vasculature in hypertension has not been evaluated.The aim was to determine the degree of association between Rho-kinase cascade activation in circulating leukocytes with cardiac and aortic Rho-kinase pathway activation in a model of hypertension and to analyze it with a cause-effect perspective.Hypertensive deoxycorticosterone (DOCA)-salt rats received the Rho-kinase antagonist fasudil (DOCA-Fas, 100 mg/kg/day, 3 weeks). Results were compared with an untreated DOCA-salt and a sham group.Rho-kinase inhibition reduced significantly blood pressure, cardiac hypertrophy, myocardial collagen and macrophage infiltration, but not aortic wall hypertrophy. Fasudil decreased significantly Rho-kinase activity in peripheral blood mononucleated cells (PBMC), myocardium and aortic wall to similar levels as in the sham group. A significant correlation was found between PBMC Rho-kinase activity and cardiac remodeling, specifically with hypertrophy ( r = 0.51, P ≤0.01), myocardial collagen ( r = 0.40, P ≤0.05) and ED1 immunostaining ( r = 0.48, P ≤0.01). In the untreated hypertensive group, increased levels ( P <0.05) of the proinflammatory molecules p65 NF-κB, vascular cell adhesion molecule 1 and interleukin-6 antibody in the myocardium, aortic wall and PBMC were observed and were reduced with fasudil ( P <0.05).In conclusion, in this hypertension model, Rho-kinase and its pathway activation determined in circulating leukocytes reflect the activation of this pathway in the myocardium and in the aortic wall and are significantly related to myocardial remodeling (hypertrophy, fibrosis and inflammation)., (© 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.)

Background: Diuretics are current antihypertensive drugs since they reduce blood pressure and cardiovascular risk. Increased vascular tone is modulated in a relevant way by the RhoA/Rho-kinase (ROCK) pathway, by acting on vascular smooth muscle cell contraction. This pathway has also proremodeling vascular effects. There are few data on the role of diuretics on both vascular ROCK activation and on proremodeling effects. We assessed the effects of hydrochlorothiazide (HCTZ) and spironolactone (spiro) alone and in combination with the ROCK inhibitor fasudil (FAS) on ROCK activation, gene expression of proremodeling markers and on hypertrophy in the aortic wall of hypertensive rats., Methods: Deoxycorticosterone acetate (DOCA)-salt hypertensive rats (male, Sprague-Dawley) were randomized to the specific ROCK inhibitor FAS, HCTZ, spiro or the combinations of FAS/HCTZ or FAS/spiro for 3 weeks. At the end of the study, ROCK activation (by western blot), gene expression of proremodeling markers (by reverse transcription polymerase chain reaction, RT-PCR) and vascular hypertrophy (by morphometry) were determined in the aortic wall., Results: All treatments significantly reduced blood pressure. In the DOCA rats the p-myosin phosphatase target protein-1 (MYPT1)/t-MYPT1 ratio, index of ROCK activation was higher by 2.8 fold (p < 0.05) compared with control rats. All treatments reduced ROCK activation in the aortic wall to control levels (p < 0.05). Besides, significantly increased protein levels of transforming growth factor β1 (TGF-β 1 ), gene expression of TGF-β 1 , connective tissue growth factor (CTGF), p22 phox and gp91 phox subunits of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, as well as increased media thickness and aortic media area/lumen area (AM/LA) in the untreated hypertensive rats were significantly reduced (p < 0.05) to control levels by all treatments. Similar effects were observed using both diuretics alone or in combination with FAS., Conclusions: In the aortic wall, both HCTZ and spiro in antihypertensive doses reduce ROCK activation, subsequent expression of genes that promote vascular remodeling and hypertrophy in this experimental model of hypertension. These effects could explain some of their clinical benefits in hypertensive patients., (© The Author(s), 2016.)

Background: The small guanosine triphosphatase RhoA and its direct target Rho kinase (ROCK) play important roles in cardiovascular pathophysiology. Activated ROCK phosphorylates intracellular proteins with detrimental effects on cardiovascular remodeling. Increased ROCK activity in circulating leukocytes is observed in hypertension and in heart failure, but its relationship with ROCK activation in the myocardium and vessels is unknown. We hypothesized that ROCK activation and phosphorylation/activation of some of its key downstream molecules in the heart and arterial wall are reflected in circulating leukocytes., Methods: Phosphorylation of MYPT1, ERM and p38-MAPK and levels of p65-NF-κB were determined in the left ventricle (LV), aortic wall and circulating leukocytes in rats with high (Brown Norway, BN) and low (Lewis) angiotensin converting enzyme. A group of BN rats received the ROCK inhibitor fasudil (7days)., Results: Compared to Lewis rats, in the BN group phosphorylated levels of MYPT1, ERM and p38-MAPK and levels of p65-NF-κB were increased (P<0.05) in the LV (67%, 92%, 52% and 98%, respectively); in the aortic wall (57%, 51%, 68% and 66%, respectively) and in circulating leukocytes (61%, 72%, 49% and 105%, respectively). Fasudil reduced all these levels to those observed in Lewis rats. Phosphorylated MYPT1, ERM, and p38-MAPK and levels of p65-NF-κB in circulating leukocytes were significantly correlated with their respective LV and aortic wall levels (excepting p65-NF-κB in aorta)., Conclusion: ROCK activity in circulating leukocytes reflects activation of this signaling pathway in the myocardium and aortic wall in this model, and supports its value as a potential cardiovascular remodeling marker., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Objective: The objective of this study was to determine the molecular mechanisms by which cardiac Rho-associated coiled-coil containing protein kinase (ROCK) activation after myocardial infarction (MI) does intervene in cardiac systolic function decline and remodeling., Methods: Simultaneous measurement of different cardiac ROCK target proteins levels, in vivo left ventricular (LV) systolic function, myocardial fibrosis and hypertrophy in rats with MI under ROCK inhibition with fasudil., Results: Seven days after MI, the ventricular mass increased significantly by 5.6% in the MI group and was reduced with fasudil. LV systolic dysfunction improved significantly with fasudil whereas cardiac ROCK activation was reduced to sham levels. The ROCK inhibitor also reduced increased cardiac levels of both ROCK1 and ROCK2 isoforms, cardiomyocyte ROCK2 fluorescence levels and β-myosin heavy chain (MHC) levels in addition to myocardial collagen volume fraction decline. Compared with sham rats, troponin phosphorylation levels after MI were similar and ROCK inhibition reduced them. MI significantly increased phosphorylation levels of extracellular-signal-regulated kinase (ERK) 42 and ERK 44 by twofold and 63%, respectively, whereas in the fasudil-treated MI group these levels were similar to those in the sham group. MI significantly increased phosphorylated levels of the transcription factor GATA-4 and the ROCK inhibitor normalized them., Conclusions: LV systolic dysfunction after MI was strongly associated with cardiac ROCK activation and subsequent phosphorylation of ROCK target proteins that promote ventricular remodeling such as β-MHC and the ERK/GATA-4 pathway. ROCK inhibition with fasudil significantly improved systolic function, diminished myocardial fibrosis and normalized β-MHC and ERK/GATA-4 phosphorylation levels., (© The Author(s), 2015.)

The newly available clinical guidelines in heart failure (HF) from Europe (2012), the United States (2010 and 2013), and Canada (2015) were compared, focusing on the systems for grading the evidence and classifying the recommendations, HF definitions, pharmacologic treatment, and devices used in HF. Some gaps were evident in the methodology for assessing evidence or in HF definitions. Pharmacologic treatments and recommendations for cardiac resynchronization therapy and implantable cardioverter-defibrillators are similar but some differences need to be considered by the practicing clinician. Guideline recommendations regarding new emergent treatments are becoming available., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The renin-angiotensin system (RAS) is a key component of cardiovascular physiology and homeostasis due to its influence on the regulation of electrolyte balance, blood pressure, vascular tone and cardiovascular remodeling. Deregulation of this system contributes significantly to the pathophysiology of cardiovascular and renal diseases. Numerous studies have generated new perspectives about a noncanonical and protective RAS pathway that counteracts the proliferative and hypertensive effects of the classical angiotensin-converting enzyme (ACE)/angiotensin (Ang) II/angiotensin type 1 receptor (AT1R) axis. The key components of this pathway are ACE2 and its products, Ang-(1-7) and Ang-(1-9). These two vasoactive peptides act through the Mas receptor (MasR) and AT2R, respectively. The ACE2/Ang-(1-7)/MasR and ACE2/Ang-(1-9)/AT2R axes have opposite effects to those of the ACE/Ang II/AT1R axis, such as decreased proliferation and cardiovascular remodeling, increased production of nitric oxide and vasodilation. A novel peptide from the noncanonical pathway, alamandine, was recently identified in rats, mice and humans. This heptapeptide is generated by catalytic action of ACE2 on Ang A or through a decarboxylation reaction on Ang-(1-7). Alamandine produces the same effects as Ang-(1-7), such as vasodilation and prevention of fibrosis, by interacting with Mas-related GPCR, member D (MrgD). In this article, we review the key roles of ACE2 and the vasoactive peptides Ang-(1-7), Ang-(1-9) and alamandine as counter-regulators of the ACE-Ang II axis as well as the biological properties that allow them to regulate blood pressure and cardiovascular and renal remodeling., (© The Author(s), 2015.)

Chronic RAS (renin-angiotensin system) activation by both AngII (angiotensin II) and aldosterone leads to hypertension and perpetuates a cascade of pro-hypertrophic, pro-inflammatory, pro-thrombotic and atherogenic effects associated with cardiovascular damage. In 2000, a new pathway consisting of ACE2 (angiotensin-converting enzyme2), Ang-(1-9) [angiotensin-(1-9)], Ang-(1-7) [angiotensin-(1-7)] and the Mas receptor was discovered. Activation of this novel pathway stimulates vasodilation, anti-hypertrophy and anti-hyperplasia. For some time, studies have focused mainly on ACE2, Ang-(1-7) and the Mas receptor, and their biological properties that counterbalance the ACE/AngII/AT1R (angiotensin type 1 receptor) axis. No previous information about Ang-(1-9) suggested that this peptide had biological properties. However, recent data suggest that Ang-(1-9) protects the heart and blood vessels (and possibly the kidney) from adverse cardiovascular remodelling in patients with hypertension and/or heart failure. These beneficial effects are not modified by the Mas receptor antagonist A779 [an Ang-(1-7) receptor blocker], but they are abolished by the AT2R (angiotensin type 2 receptor) antagonist PD123319. Current information suggests that the beneficial effects of Ang-(1-9) are mediated via the AT2R. In the present review, we summarize the biological effects of the novel vasoactive peptide Ang-(1-9), providing new evidence of its cardiovascular-protective activity. We also discuss the potential mechanism by which this peptide prevents and ameliorates the cardiovascular damage induced by RAS activation.

Background: There is experimental evidence on the role of Rho-kinase (ROCK) activation in cardiac hypertrophy but no information on its role in human hypertension and left ventricular hypertrophy (LVH). We hypothesized that ROCK activity is higher in hypertensive patients with LVH compared with hypertensive patients without LVH., Methods: We conducted a cross-sectional study comparing untreated hypertensive patients with (n = 41) and without LVH (n = 46) determined by echocardiography with a healthy normotensive control group (n = 51). Measurements included LV mass, dimensions, and function and ROCK activity determined in circulating leukocytes by measuring Western blot levels of phosphorylated to total myosin light chain phosphatase 1 (MYPT1-p/t)., Results: Compared with normotensive subjects, MYPT1-p/t was significantly increased by 4.5-fold in the hypertensive patients without LVH and by 9-fold in the hypertensive patients with LVH. Compared with the hypertension without LVH group, MYPT1-p/t was significantly increased by 2-fold in the hypertension with LVH gorup. In patients with eccentric LVH, the mean MYPT1-p/t ratio was significantly higher by 4-fold compared with hypertensive patients without eccentric LVH. Patients with an E/e' ratio ≥15 (n = 6) showed a higher MYPT1-p/t ratio (by 26%) compared with patients with a lower E/e' ratio (P ≤ 0.01)., Conclusions: ROCK activity is higher in hypertensive patients with LVH compared with hypertensive patients without LVH, and it is further increased when eccentric LVH is present. Thus, in hypertension, ROCK activation is related to pathological cardiac remodeling and might have a role as an LVH marker.

Background: Little is known about the biological effects of angiotensin-(1-9), but available evidence shows that angiotensin-(1-9) has beneficial effects in preventing/ameliorating cardiovascular remodeling., Objective: In this study, we evaluated whether angiotensin-(1-9) decreases hypertension and reverses experimental cardiovascular damage in the rat., Methods and Results: Angiotensin-(1-9) (600  ng/kg per min for 2 weeks) reduced already-established hypertension in rats with early high blood pressure induced by angiotensin II infusion or renal artery clipping. Angiotensin-(1-9) also improved cardiac (assessed by echocardiography) and endothelial function in small-diameter mesenteric arteries, cardiac and aortic wall hypertrophy, fibrosis, oxidative stress, collagen and transforming growth factor type β - 1 protein expression (assessed by western blot). The beneficial effect of angiotensin-(1-9) was blunted by coadministration of the angiotensin type 2(AT2) receptor blocker PD123319 (36  ng/kg per min) but not by coadministration of the Mas receptor blocker A779 (100  ng/kg per min). Angiotensin-(1-9) treatment also decreased circulating levels of Ang II, angiotensin-converting enzyme activity and oxidative stress in aorta and left ventricle. Whereas, Ang-(1-9) increased endothelial nitric oxide synthase mRNA levels in aorta as well as plasma nitrate levels., Conclusion: Angiotensin-(1-9) reduces hypertension, ameliorates structural alterations (hypertrophy and fibrosis), oxidative stress in the heart and aorta and improves cardiac and endothelial function in hypertensive rats. These effects were mediated by the AT2 receptor but not by the angiotensin-(1-7)/Mas receptor axis.

Objectives: Heart failure (HF) is associated with changes in myocardial metabolism that lead to impairment of contractile function. Trimetazidine (TMZ) modulates cardiac energetic efficiency and improves outcomes in ischemic heart disease. We evaluated the effects of TMZ on left ventricular ejection fraction (LVEF), cardiac metabolism, exercise capacity, O2 uptake, and quality of life in patients with nonischemic HF., Methods and Results: Sixty patients with stable nonischemic HF under optimal medical therapy were included in this randomized double-blind study. Patients were randomized to TMZ (35 mg orally twice a day) or placebo for 6 months. LVEF, 6-minute walk test (6MWT), maximum O2 uptake in cardiopulmonary exercise test, different markers of metabolism, oxidative stress, and endothelial function, and quality of life were assessed at baseline and after TMZ treatment. Left ventricular peak glucose uptake was evaluated with the use of the maximum standardized uptake value (SUV) by 18-fluorodeoxyglucose positron emission tomography ((18)FDG-PET). Etiology was idiopathic in 85% and hypertensive in 15%. Both groups were similar in age, functional class, LVEF, and levels of N-terminal pro-B-type natriuretic peptide at baseline. After 6 months of TMZ treatment, no changes were observed in LVEF (31 ± 10% vs 34 ± 8%; P = .8), 6MWT (443 ± 25 m vs 506 ± 79 m; P = .03), maximum O2 uptake (19.1 ± 5.0 mL kg(-1) min(-1) vs 23.0 ± 7.2 mL kg(-1) min(-1); P = .11), functional class (percentages of patients in functional classes I/II/III/IV 10/3753/0 vs 7/40/50/3; P = .14), or quality of life (32 ± 26 points vs 24 ± 18 points; P = .25) in TMZ versus placebo, respectively. In the subgroup of patients evaluated with (18)FDG-PET, no significant differences were observed in SUV between both groups (7.0 ± 3.6 vs 8.2 ± 3.4 respectively; P = .47)., Conclusions: In patients with nonischemic HF, the addition of TMZ to optimal medical treatment does not result in significant changes of LVEF, exercise capacity, O2 uptake, or quality of life., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Despite reduction in cardiovascular (CV) events and end-organ damage with the current pharmacologic strategies, CV disease remains the primary cause of death in the world. Pharmacological therapies based on the renin angiotensin system (RAS) blockade are used extensively for the treatment of hypertension, heart failure, and CV remodeling but in spite of their success the prevalence of end-organ damage and residual risk remain still high. Novel approaches must be discovered for a more effective treatment of residual CV remodeling and risk. The ACE2/Ang-(1-9) axis is a new and important target to counterbalance the vasoconstrictive/proliferative RAS axis. Ang-(1-9) is hydrolyzed slower than Ang-(1-7) and is able to bind the Ang II type 2 receptor. We review here the current experimental evidence suggesting that activation of the ACE2/Ang-(1-9) axis protects the heart and vessels (and possibly the kidney) from adverse cardiovascular remodeling in hypertension as well as in heart failure.

Background: The small guanosine triphosphatase Rho and its target Rho-kinase have significant roles in experimental remodeling and ventricular dysfunction, but no data are available on Rho-kinase activation in patients with heart failure (HF). We hypothesized that, in patients with chronic HF, Rho-kinase in circulating leukocytes is activated and related to left ventricular (LV) remodeling and dysfunction., Methods: Accordingly, Rho-kinase activity, assessed by the levels of phosphorylated to total myosin light chain phosphatase 1 (MYPT1-P/T) in circulating leukocytes, and echocardiographic LV function data were compared between patients with HF New York Heart Association functional class II or III due to systolic dysfunction (n = 17), healthy controls (n = 17), and hypertensive patients without HF (n = 17)., Results: In the control subjects, mean MYPT1-P/T ratio was 1.2 ± 0.2 (it was similar in the hypertensive patients without HF), whereas in patients with HF, it was significantly increased by >100-fold (P < .001). Both MYPT1-P/T and log MYPT1-P/T ratios were inversely correlated with ejection fraction (r = -0.54, P < .03 and r = -0.86, P < .001, respectively). Furthermore, in patients with HF with LV end-diastolic diameter <60 mm, MYPT1-P/T ratio was 35.8 ± 18.1, whereas it was significantly higher in patients with LV diameter ≥60 mm (P < .05)., Conclusions: Rho-Kinase activity is markedly increased in patients with stable chronic HF under optimal medical treatment, and it is associated with pathologic LV remodeling and systolic dysfunction. Mechanisms of Rho-kinase activation in patients with HF, its role in the progression of the disease, and the direct effect of Rho-kinase inhibition need further investigation., (Copyright © 2011 Mosby, Inc. All rights reserved.)

It is unknown why heart failure progresses even when patients are treated with the best therapy available. Evidences suggest that heart failure progression is due to loss of neurohumoral blockade in advanced stages of the disease and to alterations in myocardial metabolism induced, in part, by this neurohumoral activation. Alterations in cardiac energy metabolism, especially those related to substrate utilization and insulin resistance, reduce the efficiency of energy production, causing a heart energy reserve deficit. These events play a basic role in heart failure progression. Therefore, modulation of cardiac metabolism has arisen as a promissory therapy in the treatment of heart failure. This review describes myocardial energy metabolism, evaluates the role of impaired energy metabolism in heart failure progression and describes new therapies for heart failure involving metabolic intervention.

Introduction: Isoproterenol treatment of Brown Norway and Lewis rats (high and low plasma angiotensin-I-converting enzyme activity, respectively) results in similar cardiac hypertrophy but higher cardiac fibrosis in Brown Norway rats., Materials and Methods: Rats were infused in vivo with isoproterenol for two or 10 days. Cardiac fibrosis and inflammation were evaluated histochemically. We measured the mRNAs of pro-fibrotic factors (transforming growth factor beta(1), endothelin-1) and pro-inflammatory factors (monocyte chemoattractant protein-1). In studies with cardiac fibroblasts incubated with isoproterenol in vitro , we measured cell proliferation, angiotensin-I-converting enzyme and matrix metalloprotease 2 activities and deposition of collagen type I and fibronectin., Results: After treatment with isoproterenol for two days, there were large areas of myocardial injury and numerous inflammatory foci in the left ventricle, these being greater in Brown-Norway than in Lewis rats. After treatment with isoproterenol for 10 days, there were large areas of damage with extensive collagen deposition only in the left ventricle; both strains exhibited this damage which was, however, more severe in Brown-Norway than in Lewis rats. After treatment with isoproterenol for two, but not 10, days, greater amounts of monocyte chemoattractant protein-1 mRNA were found in Brown Norway than in Lewis rats. Cell proliferation, activities of angiotensin-I-converting enzyme and matrix metalloprotease 2, amounts of collagen type I and fibronectin were similar in cardiac fibroblasts from both strains; changes after isoproterenol (10 microM) were also similar in both strains., Conclusion: We conclude that the greater cardiac fibrosis in Brown Norway rats treated with isoproterenol correlates with the early and higher expression of proinflammatory factors.

Changes in cardiac osmolarity occur in myocardial infarction. Osmoregulatory mechanisms may, therefore, play a crucial role in cardiomyocyte survival. Tonicity-responsive enhancer binding protein (TonEBP) is a key transcription factor participating in the adaptation of cells to increases in tonicity. However, it is unknown whether cardiac TonEBP is activated by tonicity. Hypertonicity activated transcriptional activity of TonEBP, increased the amounts of both TonEBP mRNA and protein, and induced both the mRNA and protein of TonEBP target genes (aldose reductase and heat shock protein-70). Hypotonicity decreased the amount of TonEBP protein indicating bidirectional osmoregulation of this transcription factor. Adenoviral expression of a dominant negative TonEBP suppressed the hypertonicity-dependent increase of aldose reductase protein. These results indicated that TonEBP controls osmoregulatory mechanisms in cardiomyocytes.

The RhoA/Rho kinase (ROCK) pathway is a new mechanism of remodeling and vasoconstriction. Few data are available regarding ROCK activation when angiotensin I-converting enzyme is high and blood pressure is normal. We hypothesized that ROCK is activated in the vascular wall in normotensive rats with genetically high angiotensin I-converting enzyme levels, and it causes increased vascular expression of genes promoting vascular remodeling and also oxidative stress. Aortic ROCK activation, mRNA and protein levels (of monocyte chemoattractant protein-1, transforming growth factor [TGF]-beta(1), and plasminogen activator inhibitor-1 [PAI-1]), NADPH oxidase activity, and O(2)(*-) production were measured in normotensive rats with genetically high (Brown Norway [BN]) and low (Lewis) angiotensin-I-converting enzyme levels and in BN rats treated with the ROCK antagonist fasudil (100 mg/kg per day) for 7 days. ROCK activation was 12-fold higher in BN versus Lewis rats (P<0.05) and was reduced with fasudil by 100% (P<0.05). Aortic TGF-beta1, PAI-1, and monocyte chemoattractant protein-1 mRNA levels were higher in BN versus Lewis rats by 300%, 180%, and 1000%, respectively (P<0.05). Aortic TGF-beta1, PAI-1, and monocyte chemoattractant protein-1 protein levels were higher in BN versus Lewis rats (P<0,05). Fasudil reduced TGF-beta1 and PAI-1 mRNA and TGF-beta1, PAI-1, and monocyte chemoattractant protein-1 protein aortic levels to those observed in Lewis rats. Aortic reduced nicotinamide-adenine dinucleotide phosphate oxidase activity and (*)O(2)(-) production were increased by 88% and 300%, respectively, in BN rats (P<0.05) and normalized by fasudil. In conclusion, ROCK is significantly activated in the aortic wall in normotensive rats with genetically high angiotensin-I-converting enzyme and angiotensin II, and it causes activation of genes that promote vascular remodeling and also increases vascular oxidative stress.

The early and long-term effects of coronary artery ligation on the plasma and left ventricular angiotensin-converting enzyme (ACE and ACE2) activities, ACE and ACE2 mRNA levels, circulating angiotensin (Ang) levels [Ang I, Ang-(1-7), Ang-(1-9), and Ang II], and cardiac function were evaluated 1 and 8 weeks after experimental myocardial infarction in adult Sprague Dawley rats. Sham-operated rats were used as controls. Coronary artery ligation caused myocardial infarction, hypertrophy, and dysfunction 8 weeks after surgery. At week 1, circulating Ang II and Ang-(1-9) levels as well as left ventricular and plasma ACE and ACE2 activities increased in myocardial-infarcted rats as compared with controls. At 8 weeks post-myocardial infarction, circulating ACE activity, ACE mRNA levels, and Ang II levels remained higher, but plasma and left ventricular ACE2 activities and mRNA levels and circulating levels of Ang-(1-9) were lower than in controls. No changes in plasma Ang-(1-7) levels were observed at any time. Enalapril prevented cardiac hypertrophy and dysfunction as well as the changes in left ventricular ACE, left ventricular and plasmatic ACE2, and circulating levels of Ang II and Ang-(1-9) after 8 weeks postinfarction. Thus, the decrease in ACE2 expression and activity and circulating Ang-(1-9) levels in late ventricular dysfunction post-myocardial infarction were prevented with enalapril. These findings suggest that in this second arm of the renin-angiotensin system, ACE2 may act through Ang-(1-9), rather than Ang-(1-7), as a counterregulator of the first arm, where ACE catalyzes the formation of Ang II.

Cardiac hypertrophy is one of the main ways in which cardiomyocytes respond to mechanical and neurohormonal stimuli. It enables myocytes to increase their work output, which improves cardiac pump function. However, this compensatory mechanism can become overwhelmed by biomechanical stress, thereby resulting in heart failure, which is associated with high morbidity and mortality. The complex molecular processes that lead to cardiomyocyte growth involve membrane receptors, second messengers, and transcription factors. The common final pathway of all these intracellular substances is gene expression, whose variations are being revealed in increasing detail. The genetic response is characterized by the re-expression of fetal genes, an event which is regarded as the molecular marker of pathologic cardiac hypertrophy, and which is absent in normal physiologic cardiac growth. The possibility of stopping or reversing pathologic cardiac hypertrophy and, thereby, slowing the development of heart failure is a topic of considerable clinical interest and a large amount of relevant data has accumulated. The purpose of this review was to provide a schematic overview of current knowledge about the molecular pathogenesis of cardiomyocyte hypertrophy, with special emphasis on new research topics and investigations.

To determine circulating angiotensin-(1-7) [Ang-(1,7)] levels in rats with different angiotensin converting enzyme (ACE) genotypes and to evaluate the effect of hypertension on levels of this heptapeptide, plasma levels of angiotensin II (Ang II) and Ang-(1-7) were determined by HPLC and radioimmunoassay in (a) normotensive F0 and F2 homozygous Brown Norway (BN; with high ACE) or Lewis (with low ACE) rats and (b) in hypertensive F2 homozygous male rats (Goldblatt model). Genotypes were characterized by PCR and plasma ACE activity measured by fluorimetry. Plasma ACE activity was 2-fold higher (p < 0.05) in homozygous BN compared to homozygous Lewis groups. In the Goldblatt groups, a similar degree of hypertension and left ventricular hypertrophy was observed in rats with both genotypes. Plasma Ang II levels were between 300-400% higher (p < 0.05) in the BN than in the Lewis rats, without increment in the hypertensive animals. Plasma Ang-(1-7) levels were 75-87% lower in the BN rats (p < 0.05) and they were significantly higher (p < 0.05) in the hypertensive rats from both genotypes. Plasma levels of Ang II and Ang-(1-7) levels were inversely correlated in the normotensive rats (r = -0.64; p < 0.001), but not in the hypertensive animals. We conclude that there is an inverse relationship between circulating levels of Ang II and Ang-(1-7) in rats determined by the ACE gene polymorphism. This inverse relation is due to genetically determined higher ACE activity. Besides, plasma levels of Ang-(1-7) increase in renovascular hypertension.

In humans and rats, angiotensin I-converting enzyme activity is significantly determined by a gene polymorphism. Homozygous Brown Norway rats have higher plasma angiotensin I-converting enzyme activity and circulating angiotensin II (Ang II) levels than Lewis rats. Because Ang II induces NAD(P)H oxidase activation, we hypothesized here that Brown Norway rats have higher vascular NAD(P)H oxidase activity and superoxide anion production than Lewis rats. Homozygous Brown Norway (n=15) and Lewis (n=13) male rats were used. Plasma angiotensin I-converting enzyme activity (by fluorimetry), Ang II levels (by high-performance liquid chromatography and radioimmunoassay), and aortic NAD(P)H oxidase activity, as well as superoxide anion production (by chemiluminescence with lucigenin) were measured. Plasma angiotensin I-converting enzyme activity and Ang II levels were 100% higher in Brown Norway rats than in Lewis rats (P<0.05). Aortic angiotensin I- converting enzyme, but not Ang II, was elevated (P<0.05). Aortic superoxide anion production and NAD(P)H oxidase activity were 300% and 260% higher in Brown Norway than in Lewis rats, respectively (P<0.05), which was not observed in Brown Norway rats treated with candesartan (10 mg/kg per day for 7 days). Endothelial NO synthase activity in the aorta from Brown Norway rats was significantly lower than in Lewis rats. However, inducible NO synthase activity and both endothelial NO synthase and inducible NO synthase mRNA and protein levels were similar in both genotypes. In summary, Brown Norway rats have higher vascular NAD(P)H oxidase activity and superoxide anion production than Lewis rats, suggesting the presence of a higher level of vascular oxidative stress in rats with genetically higher angiotensin I-converting enzyme levels. This effect is mediated through the angiotensin I receptor.

Administration of the beta-adrenergic agonist isoproterenol results in cardiac apoptosis. The effect of short-term beta-adrenergic stimulation by isoproterenol on the activity of plasma, lung, and left ventricular (LV) angiotensin I-converting enzyme (ACE) activity and its association with the development of cardiac apoptosis was investigated. beta-Adrenergic stimulation for 24 hours produced an early increase only in the proapoptotic proteins bax and bcl-XS without changes in the levels of the antiapoptotic protein bcl-XL. The ratio between these bcl family proteins was indicative of apoptosis and correlated with an early and significant increase (300%) in DNA laddering. However, after 5 days of the beta-adrenergic stimulation, the ratio changed in favor of antiapoptotic proteins and correlated with the absence of DNA fragmentation. In addition, LV and plasma ACE activities increased markedly with isoproterenol over the study period up to 5 days. ACE activity also regulated expression of the antiapoptotic gene bcl-XL. The administration of perindopril (an ACE inhibitor) prevented the observed increase in bax and bcl-XS levels and attenuated (50% decrease, P<0.05) the effect of isoproterenol on DNA fragmentation. Thus, early and transient cardiac apoptosis triggered by the beta-adrenergic agonist isoproterenol is reversed in the presence of perindopril.

There is a large amount of information in the literature to state that blood pressure control using ambulatory blood pressure measurement has a better predictive value for future cardiovascular events and target organ damage than casual blood pressure measurements. Clinical studies are currently evaluating if this approach is cost-effective. At the present time, and in the usual clinical practice, the use of ambulatory blood pressure monitoring is recommended for patients with resistant or difficult-to-control hypertension, for hypertensive patients with previous cardiovascular events or significant target organ damage, for the diagnosis of white coat hypertension, when there are symptoms suggesting hypotension or there is large variability in casual blood pressure measurements.

Neutral endopeptidase (NEP) hydrolyses angiotensins (Ang) I and II and generates angiotensin-(1-7) [Ang-(1-7)]. In humans, the insertion/deletion (I/D) angiotensin-I converting enzyme (ACE) gene polymorphism determined plasma ACE levels by 40%. In rats, a similar polymorphism determines ACE levels which are inversely associated to NEP activity. The objective of this study is to evaluate the relationship between ACE expression and plasma NEP activity in normotensive subjects and in hypertensive patients. In total, 58 consecutive patients with hypertension, evaluated in our Hypertension Clinic, were compared according to their ACE I/D genotypes with 54 control subjects in terms of both plasma ACE activity and NEP activities. Plasma ACE activity was elevated 51 and 70% in both DD ACE groups (normotensives and hypertensives) compared with their respective ID and II ACE groups (P<0.001). A significant effect of the ACE polymorphism and of the hypertensive status on ACE activity was observed (P<0.001). In normotensive DD ACE subjects, NEP activity was 0.30+/-0.02 U/ml, whereas in the normotensive II ACE and in the normotensive ID ACE subjects NEP activity was increased 65 and 48%, respectively (P<0.001). In the hypertensive DD ACE patients, NEP activity was 0.47+/-0.03 U/mg. An effect of the I/D ACE genotypes on NEP activity (P<0.04) and an interaction effect between the I/D ACE genotype and the hypertensive status were also observed (P<0.001). These results are consistent with a normal and inverse relationship between the ACE polymorphism and NEP activity in normotensive humans (as is also observed in rats). This normal relationship is not observed in hypertensive patients.