Publications by authors named "Ennis I"

Cardiovascular (CV) disease is the major cause of mortality. Estrogens (E) exert multiple CV and neuroprotective effects. During menopause, CV and cognitive pathologies increase dramatically.

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IGF-1 and apelin are released in response to exercise training with beneficial effects. Previously we demonstrated that a swimming routine is effective to convert pathological into physiological cardiac hypertrophy, and that IGF-1 improves contractility and the redox state, in spontaneously hypertensive rats (SHR). Now, we hypothesize that the apelinergic pathway is involved in the cardioprotective effects of IGF-1 in the SHR.

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It has been demonstrated the dysregulation of the cardiac endocannabinoid system in cardiovascular diseases. Thus, the modulation of this system through the administration of phytocannabinoids present in medicinal cannabis oil (CO) emerges as a promising therapeutic approach. Furthermore, phytocannabinoids exhibit potent antioxidant properties, making them highly desirable in the treatment of cardiac pathologies, such as hypertension-induced cardiac hypertrophy (CH).

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Background: It has been previously demonstrated that the maintenance of ischemic acidic pH or the delay of intracellular pH recovery at the onset of reperfusion decreases ischemic-induced cardiomyocyte death.

Objective: To examine the role played by nitric oxide synthase (NOS)/NO-dependent pathways in the effects of acidic reperfusion in a regional ischemia model.

Methods: Isolated rat hearts perfused by Langendorff technique were submitted to 40 min of left coronary artery occlusion followed by 60 min of reperfusion (IC).

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The myocardium is a highly oxidative tissue in which mitochondria are essential to supply the energy required to maintain pump function. When pathological hypertrophy develops, energy consumption augments and jeopardizes mitochondrial capacity. We explored the cardiac consequences of chronic swimming training, focusing on the mitochondrial network, in spontaneously hypertensive rats (SHR).

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Article Synopsis
  • The COVID-19 pandemic has caused significant mortality while revealing long-term effects known as long COVID, affecting various body systems, including bone health.
  • This study examines how acute infection with SARS-CoV-2, particularly the ancestral and Omicron strains, influences the formation of osteoclasts—bone-resorbing cells.
  • Findings indicate that both viral strains increase osteoclast formation and specific gene expressions related to osteoclastogenesis, opening up new research possibilities for understanding bone health in COVID-19 patients.
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The Argentinean Society of Hypertension, in agreement with the May Measurement Month (MMM) initiative of the International Society of Hypertension, implemented for the third consecutive year a hypertension screening campaign. A volunteer cross-sectional survey was carried out in public spaces and health centres during the month of May 2019 across 33 cities in Argentina. Hypertension was defined as systolic blood pressure (BP) ≥140 mmHg and/or diastolic BP ≥90 mmHg based on the mean of the second and third BP measurements, or in those on treatment for high BP.

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The present document provides scientific evidence reviewed and analysed by a group of specialist clinicians in hypertension that aims to give an insight into a pharmacological strategy to improve blood pressure control. Evidence shows that most hypertensive patients will need at least two drugs to achieve blood pressure goals. There is ample evidence showing that treatment adherence is inversely related to the number of drugs taken.

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Current evidence reveals that cardiac mineralocorticoid receptor (MR) activation following myocardial stretch plays an important physiological role in adapting developed force to sudden changes in hemodynamic conditions. Its underlying mechanism involves a previously unknown nongenomic effect of the MR that triggers redox-mediated Na/H exchanger (NHE1) activation, intracellular Na accumulation, and a consequent increase in Ca transient amplitude through reverse Na/Ca exchange. However, clinical evidence assigns a detrimental role to MR activation in the pathogenesis of severe cardiac diseases such as congestive heart failure.

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Physical training stimulates the development of physiologic cardiac hypertrophy (CH), being a key event in this process the inhibition of the Na/H exchanger. However, the role of the sodium bicarbonate cotransporter (NBC) has not been explored yet under this circumstance. C57/Bl6 mice were allowed to voluntary exercise (wheel running) for five weeks.

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Hypertension continues to be the leading cause of death and disability in the industrialized world, with a high level of unawareness and unacceptably poor control. Therefore, the Argentinian Society of Hypertension, in agreement with the May Measurement Month (MMM) initiative of the International Society of Hypertension, implemented for the second consecutive year an educational campaign during the month of May 2018. A volunteer cross-sectional survey was carried out in public spaces and health centres during the month of May 2018 across 33 cities in Argentina.

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The association between hypertension, diabetes, cardio and cerebrovascular disease and severe and fatal COVID-19, described in different countries, is remarkable. Myocardial damage and myocardial dysfunction are postulated as a possible causal nexus. Frequent findings of elevated troponin levels and electrocardiographic anomalies support this concept.

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The first case of COVID-19 was reported on 31 December 2019 in Wuhan, China. Ever since there has been unprecedented and growing interest in learning about all aspects of this new disease. Debate has been generated as to the association between antihypertensive therapy with renin-angiotensin-aldosterone system (RAAS) inhibitors and SARS-CoV-2 infection.

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Na/H exchanger and cardiac hypertrophy.

Hipertens Riesgo Vasc

November 2020

Reactive cardiac hypertrophy (CH) is an increase in heart mass in response to hemodynamic overload. Exercise-induced CH emerges as an adaptive response with improved cardiac function, in contrast to pathological CH that represents a risk factor for cardiovascular health. The Na/H exchanger (NHE-1) is a membrane transporter that not only regulates intracellular pH but also intracellular Na concentration.

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Aim: Myocardial Na/H exchanger-1 (NHE-1) hyperactivity and oxidative stress are interrelated phenomena playing pivotal roles in the development of pathological cardiac hypertrophy and heart failure. Exercise training is effective to convert pathological into physiological hypertrophy in the spontaneously hypertensive rats (SHR), and IGF-1-key humoral mediator of exercise training-inhibits myocardial NHE-1, at least in normotensive rats. Therefore, we hypothesize that IGF-1 by hampering NHE-1 hyperactivity and oxidative stress should exert a cardioprotective effect in the SHR.

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Background/aims: Myocardial stretch increases cardiac force in two consecutive phases: The first one due to Frank-Starling mechanism, followed by the gradually developed slow force response (SFR). The latter is the mechanical counterpart of an autocrine/paracrine mechanism involving the release of angiotensin II (Ang II) and endothelin (ET) leading to Na⁺/H⁺ exchanger 1 (NHE-1) phosphorylation and activation. Since previous evidence indicates that p38-MAP kinase (p38-MAPK) negatively regulates the Ang II-induced NHE1 activation in vascular smooth muscle and the positive inotropic effect of ET in the heart, we hypothesized that this kinase might modulate the magnitude of the SFR to stretch.

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Chronic activation of the renin angiotensin system (RAS) favors several cardiac diseases, among which myocardial hypertrophy occupies an outstanding place. In this context, the hyperactivity of the cardiac Na/H (NHE-1) exchanger plays a key role. The pathologic remodeling of the myocardium constitutes an independent risk factor for morbidity and mortality with continuously increasing healthcare cost.

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Cardiac adaptation to endurance training includes improved contractility by a non-yet clarified mechanism. Since IGF-1 is the main mediator of the physiological response to exercise, we explored its effect on cardiac contractility and the putative involvement of nitric oxide (NO) and CaMKII in control and swim-trained mice. IGF-1 increased cardiomyocyte shortening (128.

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Introduction: Increased cardiac mass, as well as reduced arterial distensibility, are well recognised independent cardiovascular risk factors.

Objective: The aim of this study was to determine the existence of early structural and/or functional alterations of the left ventricle (LV) and the aortic root in young people with optimal (O), normal (N) or normal-high (HN) blood pressure (BP).

Material And Methods: BP was recorded, and LV mass (LVM), LV function, and aortic distensibility (AD) were evaluated by echocardiogram in medical students.

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We examined the effect of specific and local silencing of sodium/hydrogen exchanger isoform 1 (NHE1) with a small hairpin RNA delivered by lentivirus (L-shNHE1) in the cardiac left ventricle (LV) wall of spontaneously hypertensive rats, to reduce cardiac hypertrophy. Thirty days after the lentivirus was injected, NHE1 protein expression was reduced 53.3 ± 3% in the LV of the L-shNHE1 compared with the control group injected with L-shSCR (NHE1 scrambled sequence), without affecting its expression in other organs, such as liver and lung.

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Background: Reactive oxygen species, such as superoxide, are being increasingly recognized as key components of a vast array of signaling pathways. Angiotensin II is a well-recognized stimulus for superoxide production through NADPH oxidase activation and opening of the mitochondrial ATP-sensitive potassium channels (mKATP). A role for this mechanism has been proposed to explain several physiological effects of the peptide.

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Background: The involvement of NHE-1 hyperactivity, critical for pathological cardiac hypertrophy (CH), in physiological CH has not been elucidated yet. Stimulation of NHE-1 increases intracellular Na(+) and Ca(2+) favouring calcineurin activation. Since myocardial stretch, an activator of NHE-1, is common to both types of CH, we speculate that NHE-1 hyperactivity may also happen in physiological CH.

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Mineralocorticoid receptor (MR) antagonists decrease morbidity and mortality in heart failure patients for whom oxidative stress is usual; however, the underlying mechanism for this protection is unclear. Since aldosterone stimulates reactive oxygen species (ROS) production in several tissues, we explored its effect and the intracellular pathway involved in the rat myocardium. Aldosterone dose-dependently increased O2(-) production in myocardial slices.

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Emerging evidence supports a key role for endothelin-1 (ET-1) and the transactivation of the epidermal growth factor receptor (EGFR) in angiotensin II (Ang II) action. We aim to determine the potential role played by endogenous ET-1, EGFR transactivation and redox-dependent sodium hydrogen exchanger-1 (NHE-1) activation in the hypertrophic response to Ang II of cardiac myocytes. Electrically paced adult cat cardiomyocytes were placed in culture and stimulated with 1 nmol l(-1) Ang II or 5 nmol l(-1) ET-1.

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Article Synopsis
  • Myocardial stretch activates an angiotensin II-dependent loop that triggers redox-sensitive signaling pathways through reactive oxygen species, and mineralocorticoid receptors (MR) play a crucial role in this process.
  • Researchers used a lentiviral vector to knock down MR in Wistar rats and analyzed its effects on cardiac signaling and responses to stretch and angiotensin II.
  • Results showed that reducing MR expression led to decreased production of reactive oxygen species in response to angiotensin II, lack of stretch-induced kinase activation, and impaired cardiac force generation, highlighting MR's importance in myocardial stretch responses.
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