endothelin-1 and Hypertrophy--Left-Ventricular

Polycystic ovary syndrome (PCOS) is a good example of obesity-related cardiovascular complication affecting young women. PCOS is not only considered a reproductive problem but rather represents a complex endocrine, multifaceted syndrome with important health implications. Several evidences suggest an increased cardiovascular risk of cardiovascular disease associated with this syndrome, characterized by an impairment of heart structure and function, endothelial dysfunction and lipid abnormalities. All these features, probably linked to insulin-resistance, are often present in obese PCOS patients. Cardiovascular abnormalities represent important long-term sequelae of PCOS that need further investigations.

Topics: Biomarkers; Cardiovascular Diseases; Endothelin-1; Female; Humans; Hypertrophy, Left Ventricular; Insulin Resistance; Obesity; Plasminogen Activator Inhibitor 1; Polycystic Ovary Syndrome; Risk Assessment; Risk Factors

Myocardial remodeling invariably occurs in congestive heart failure (CHF) and is a response to a prolonged cardiovascular stress, which is characterized by a cascade of compensatory structural events. Remodeling of the myocardial interstitium occurs in CHF and likely contributes to the progression of the remodeling process. The myocardial matrix can be considered a biological highway in which a large amount of signaling proteins and structural proteins are being moved within the interstitium, entering and exiting the interstitial space, and docking to cellular components. The rates at which these events occur can accelerate and decelerate depending on the particular cardiac disease state and thereby can alter the course of myocardial remodeling. Once considered merely a scaffolding to align cells, the matrix plays a complex and divergent role in influencing cell behavior. For example, the matrix has a functional role in cell migration, proliferation, adhesion, and cell-to-cell signaling. In light of this, the myocardial matrix should not be regarded as merely a static structure, but rather, as a complex system of dynamic interactions between matrix molecules, signaling proteins, and transmembrane proteins. Specific strategies that are targeted at modifying activity along this matrix highway will likely alter the course of myocardial remodeling and heart failure.

Topics: Angiotensin II; Disease Progression; Endothelin-1; Extracellular Matrix; Heart Failure; Humans; Hypertrophy, Left Ventricular; Integrins; Matrix Metalloproteinases; Myocardial Infarction; Myocardium; Transforming Growth Factor beta; Ventricular Remodeling

In addition to its vasoactive effects, endothelin-1 (ET-1) causes hypertrophy of isolated cardiac myocytes. Since the early 1990s, the cell signaling events initiated by the binding of ET-1 to its cell surface receptors on the myocyte, and their roles in myocyte hypertrophy have been a particular interest of mine. ET-1 activates several intracellular signaling pathways in cardiac myocytes, notably the protein kinase C pathway and the mitogen-activated protein kinase cascades. It is likely that activation of these pathways contributes to the hypertrophic response. More recently, ET-1 has been shown to activate the phosphatidylinositol 3-kinase/Akt pathway, although the activation is relatively weak in comparison to other agonists. The actions of 2 other vasoactive peptides, angiotensin II and bradykinin, on the heart or cardiac myocyte in relation to cardiac hypertrophy are also discussed.

Topics: Angiotensin II; Animals; Bradykinin; Endothelin-1; Humans; Hypertrophy, Left Ventricular; Myocytes, Cardiac; Protein Kinase C; Renin-Angiotensin System; Signal Transduction

The sampling included 231 patient with hypertension disease of stage I-II. The hypertrophy of left ventricle of heart was established in 97 patients (group I) and 134 patients had no hypertrophy of left ventricle of heart (group II). The control group consisted of 25 healthy persons. The increase of tumor necrosis factor alpha and interleukin beta was established in group I as compared with group II and control group. In patients of group I the expressed dysfunction of endothelium was observed. The increase of endothelin I and number of desquamated endotheliocytes as compared with group II and healthy persons was established. The direct relationship between increase of concentration of analyzed cytokines and presence of hypertrophy of left ventricle of heart is revealed.

Topics: Adult; Endothelin-1; Endothelium, Vascular; Female; Humans; Hypertension; Hypertrophy, Left Ventricular; Immune System Diseases; Male; Middle Aged; Tumor Necrosis Factor-alpha

Patients with hypertensive left-ventricular hypertrophy (LVH) have lower coronary flow reserve (CFR). Whether carvedilol can improve CFR of patients with hypertensive LVH is unknown. We aimed to investigate the effects of carvedilol on CFR in patients with hypertensive LVH.. Sixty-three patients were randomly divided into two groups for treatment with carvedilol or metoprolol. The peak diastolic coronary flow velocity in the left anterior descending coronary artery at rest and at maximal vasodilation with dipyridamole infusion was recorded by transesophageal echocardiography (TEE), then CFR was calculated at baseline and at the end of 6 months of therapy. Left-ventricular mass index (LVMI) was calculated by 2-D echocardiography. Endothelium-dependent and -independent reactivity of the brachial artery was measured. Levels of plasma endothelin-1 (ET1), nitric oxide (NO) and other metabolites were monitored and analyzed before and after 6-month therapy.. Both blood pressure and heart rate decreased significantly in the two treatment groups after therapy (p<0.05). With carvedilol treatment, LVMI was lower (p<0.05), endothelium function of the brachial artery was higher (p<0.05), and peak diastolic coronary flow velocity at rest and at maximal vasodilation after dipyridamole infusion was significantly higher (p<0.05) than with metoprolol treatment, which led to a significantly higher CFR (p<0.05). Changes in CFR and LVMI with carvedilol treatment were inversely correlated (R(2)=0.474, p=0.036). With carvedilol treatment, plasma level of ET-1 was lower, but that of NO was significantly higher than with metoprolol treatment (both p<0.05).. The CFR of patients with hypertensive LVH but not coronary artery disease could increase with 6-month carvedilol therapy.

Topics: Administration, Sublingual; Adrenergic beta-Antagonists; Aged; Blood Flow Velocity; Blood Pressure; Brachial Artery; Carbazoles; Carvedilol; Coronary Circulation; Diastole; Dipyridamole; Echocardiography, Transesophageal; Endothelin-1; Endothelium, Vascular; Female; Heart Rate; Humans; Hypertension; Hypertrophy, Left Ventricular; Injections, Intravenous; Male; Metoprolol; Middle Aged; Nitroglycerin; Propanolamines; Vasodilation; Vasodilator Agents

Coarctation of the aorta is associated with increased risk for hypertension in adulthood, despite successful repair. The intrinsic mechanisms underscoring hypertension and left ventricular performance in these patients, however, remains to be determined. Our objective was to evaluate left ventricular performance by means of echocardiographic and biochemical parameters at midterm follow-up in normotensive children who have had undergone successful surgical or catheter interventional treatment of coarctation with a residual gradient of less than 20 mmHg at rest. We studied prospectively 14 patients with native aortic coarctation who underwent surgery or balloon angioplasty, the cohort made up of equal numbers of boys and girls, and having a mean age of 8.5 plus or minus 4 years. We also studied 30 age-matched healthy subjects, measuring mitral inflow pulsed wave signals, isovolumic relaxation and contraction times, myocardial performance index parameters, and levels of B-type natriuretic peptide and endothelin-1 in both groups. We found no differences in systolic blood pressure at rest between the patients and their controls. The ventricular septal diastolic dimensions, left ventricular posterior wall dimensions, mitral valve E wave, deceleration time, isovolumic relaxation time, isovolumic contraction time and myocardial performance index were all significantly increased in the patients. Levels of plasma B-type natriuretic peptide and endothelin-1 were also significantly higher in the patients when compared to the control group. We conclude that aortic coarctation is a chronic disease characterized by persistency of myocardial and vascular alterations. The elevated levels of plasma b-type natriuretic peptide and endothelin-1 may be indicative of late onset hypertension after successful treatment of native coarctation in early childhood.

Topics: Adolescent; Angioplasty, Balloon; Aortic Coarctation; Biomarkers; Blood Pressure Determination; Cardiac Catheterization; Cardiac Surgical Procedures; Child; Diastole; Echocardiography, Doppler; Endothelin-1; Endothelium, Vascular; Female; Follow-Up Studies; Heart Function Tests; Humans; Hypertrophy, Left Ventricular; Male; Myocardial Contraction; Natriuretic Peptide, Brain; Observer Variation; Probability; Prospective Studies; Time Factors; Treatment Outcome

Studies suggest that endothelin-1 contributes to the pathogenesis of hypertension. A G5665T gene polymorphism of preproendothelin-1 has been shown to be associated with higher blood pressure in overweight patients. No study has yet determined the effect of this polymorphism on the change in blood pressure during antihypertensive treatment.. This study aimed to determine this effect in hypertensive patients with left ventricular (LV) hypertrophy during antihypertensive treatment with either irbesartan or atenolol.. We determined the preproendothelin-1 genotype using minisequencing in 102 patients with essential hypertension and LV hypertrophy verified by echocardiography, randomized in a double-blind fashion to treatment with either the AT1-receptor antagonist irbesartan or the beta1-adrenoceptor antagonist atenolol.. The change in systolic blood pressure (SBP) after 12 weeks of treatment was related to the preproendothelin-1 genotype in men; after adjustment for potential covariates (age, blood pressure, and LV mass index at study entry, dose of irbesartan/atenolol, and type of treatment), those carrying the T-allele responded on average with a more than two-fold greater reduction than those with the G/G genotype (-21.9 mmHg 13.9] vs. -8.9 [2.3], p = 0.007). No significant differences in blood pressure change between G/G and carriers of the T-allele were seen among women.. Our finding suggests a gender-specific relationship between the G5665T preproendothelin-1 polymorphism and change in SBP in response to antihypertensive treatment with irbesartan or atenolol, suggesting the endothelin pathway to be a common mechanism included in the hypertensive action of the drugs.

Topics: Antihypertensive Agents; Atenolol; Biphenyl Compounds; Blood Pressure; Endothelin-1; Female; Genotype; Humans; Hypertension; Hypertrophy, Left Ventricular; Irbesartan; Male; Middle Aged; Polymorphism, Genetic; Sex Factors; Tetrazoles; Treatment Outcome

Previous studies have underlined the substantial role of nuclear factor of activated T cells (NFAT) in hypertension-induced myocardial hypertrophy ultimately leading to heart failure. Here, we aimed at neutralizing four members of the NFAT family of transcription factors as a therapeutic strategy for myocardial hypertrophy transiting to heart failure through AAV-mediated cardiac expression of a RNA-based decoy oligonucleotide (dON) targeting NFATc1-c4. AAV-mediated dON expression markedly decreased endothelin-1 induced cardiomyocyte hypertrophy in vitro and resulted in efficient expression of these dONs in the heart of adult mice as evidenced by fluorescent in situ hybridization. Cardiomyocyte-specific dON expression both before and after induction of transverse aortic constriction protected mice from development of cardiac hypertrophy, cardiac remodeling, and heart failure. Singular systemic administration of AAVs enabling a cell-specific expression of dONs for selective neutralization of a given transcription factor may thus represent a novel and powerful therapeutic approach.

Topics: Animals; Cells, Cultured; Dependovirus; Disease Models, Animal; Endothelin-1; Genetic Therapy; Genetic Vectors; Heart Failure; Hypertrophy, Left Ventricular; Mice, Inbred C57BL; Myocytes, Cardiac; NFATC Transcription Factors; Oligonucleotides; Rats, Wistar; Ventricular Function, Left; Ventricular Remodeling

The aim of the study was to find dependence of left ventricular hypertrophy indexes to polymorphism of Les198Asn gene endothelin-1 and BMI.. Materials and methods: We took research in 160 patients with arterial hypertension, using ECG and polymerase chain reaction (PCR). Groups were divided additionally according to BMI (body mass index).. Results: It was found, that patients with obesity had their Left ventricular mass and hypertrophy left ventricular indexes higher, than in patients with normal and increased body weight. Carriers of Asn198Asn and Lys198Asn genotypes Left ventricular mass and hypertrophy left ventricular indexes are higher than in carriers of Lys198Lys genotype.. Conclusions: It was determined that in patients-carriers of Asn198Asn genotype, Left ventricular mass (LVMI) and hypertrophy left ventricular indexes (LVMMI) were higher compared to patients-carriers of Lys198Lys and Lys198Asn type, both in men and women. The dependence of LVMI and LVMMI are shown to be higher in patients with obesity than in people with normal and increased body mass.

Topics: Endothelin-1; Female; Genotype; Heart Ventricles; Humans; Hypertension; Hypertrophy, Left Ventricular; Male; Obesity; Polymorphism, Genetic

The survival rates of women with breast cancer have improved significantly over the last four decades due to advances in breast cancer early diagnosis and therapy. However, breast cancer survivors have an increased risk of cardiovascular complications following chemotherapy. While this increased risk of later occurring structural cardiac remodeling and/or dysfunction has largely been attributed to the cardiotoxic effects of breast cancer therapies, the effect of the breast tumor itself on the heart prior to cancer treatment has been largely overlooked. Thus, the objectives of this study were to assess the cardiac phenotype in breast cancer patients prior to cancer chemotherapy and to determine the effects of human breast cancer cells on cardiomyocytes.. We investigated left ventricular (LV) function and structure using cardiac magnetic resonance imaging in women with breast cancer prior to systemic therapy and a control cohort of women with comparable baseline factors. In addition, we explored how breast cancer cells communicate with the cardiomyocytes using cultured human cardiac and breast cancer cells.. Our results indicate that even prior to full cancer treatment, breast cancer patients already exhibit relative LV hypertrophy (LVH). We further demonstrate that breast cancer cells likely contribute to cardiomyocyte hypertrophy through the secretion of soluble factors and that at least one of these factors is endothelin-1.. Overall, the findings of this study suggest that breast cancer cells play a greater role in inducing structural cardiac remodeling than previously appreciated and that tumor-derived endothelin-1 may play a pivotal role in this process.

Topics: Breast Neoplasms; Case-Control Studies; Cell Communication; Cell Line, Tumor; Cells, Cultured; Culture Media, Conditioned; Endothelin-1; Female; Humans; Hypertrophy; Hypertrophy, Left Ventricular; Magnetic Resonance Imaging; Middle Aged; Myocytes, Cardiac; Paracrine Communication; Retrospective Studies; Tumor Cells, Cultured; Ventricular Remodeling

Topics: Biomarkers; C-Reactive Protein; Endothelin-1; Endothelium, Vascular; Humans; Hypertrophy, Left Ventricular; Inflammation Mediators; Interleukin-6; Nitric Oxide; Phosphorus; Tumor Necrosis Factor-alpha; Uremia; Ventricular Function, Left; Ventricular Remodeling

Patients undergoing surgical repair of aortic coarctation have a 50% risk of pathologic left ventricular remodeling (increased left ventricular mass or relative wall thickness). Endothelin 1, ST2, galectin 3, norepinephrine and B-natriuretic peptide are biomarkers that have been associated with pathologic LV change in adult populations but their predictive value following pediatric coarctation repair are not known.. Biomarker levels at coarctation repair will predict persistent left ventricular remodeling at 1-year follow up.. Prospective, cohort study of 27 patients' age 2 days-12 years with coarctation of the aorta undergoing surgical repair. Echocardiograms were performed preoperation, postoperation, and at 1-year follow-up. Plasma biomarker levels were measured at the peri-operative time points. Association between biomarker concentrations and echocardiographic parameters was assessed.. Neither left ventricular mass index nor relative wall thickness varied from pre-op to post-op. At pre-op, relative wall thickness was elevated in 52% and left ventricular mass index was elevated in 22%; at follow-up, relative wall thickness was elevated in 13% and left ventricular mass index was elevated in 8%. Presence of residual coarctation did not predict left ventricular remodeling (AUC 0.59; P > .05). Multivariable receiver operating characteristic curve combining pre-op ST2 and endothelin 1 demonstrated significant predictive ability for late pathologic left ventricular remodeling (AUC 0.85; P = .02).. Persistent left ventricular hypertrophy and abnormal relative wall thickness at intermediate-term follow-up was rare compared to previous studies. A model combining pre-op endothelin 1 and ST2 level demonstrated reasonable accuracy at predicting persistent abnormalities in this cohort. Larger studies will be needed to validate this finding and further explore the mechanism of persistent left ventricular remodeling in this population.

Topics: Adolescent; Aortic Coarctation; Biomarkers; Cardiac Surgical Procedures; Child; Child, Preschool; Endothelin-1; Female; Humans; Hypertrophy, Left Ventricular; Infant; Infant, Newborn; Interleukin-1 Receptor-Like 1 Protein; Male; Prospective Studies; Risk Factors; Time Factors; Treatment Outcome; Ventricular Function, Left; Ventricular Remodeling

In chronic kidney disease (CKD), endothelin-1 (ET-1) always increases and there are changes in cardiac ultrasonography. In the present study, we aimed at investigating the role of serum ET-1 in predicting cardiac complications in patients with CKD.. The level of serum ET-1 was measured by enzyme-linked immunosorbent assay (ELISA) and cardiac ultrasonography was performed in enrolled patients. Indexes of heart failure, such as left ventricular mass index, interventricular septum thickness and left ventricular end diastolic diameter, were measured in patients with CKD.. In the present study, we found that the level of serum ET-1 was significantly correlated with left ventricular mass index, interventricular septum thickness and left ventricular end diastolic diameter (p < .001) in non-dialysis patients with CKD.. The results of the present study indicated that the level of serum ET-1 is closely related to the cardiac complications of CKD and is a useful predictor of cardiac complication.

Topics: Adult; Echocardiography; Endothelin-1; Female; Heart Ventricles; Humans; Hypertrophy, Left Ventricular; Male; Middle Aged; Renal Insufficiency, Chronic; Ventricular Dysfunction, Left; Ventricular Remodeling; Ventricular Septum

Left ventricular hypertrophy (LVH) is a common abnormality in hemodialysis (HD) patients. Mitochondrial dysfunction contributes to the progression of LVH. As an inner mitochondrial membrane structural protein, mitofilin plays a key role in maintaining mitochondrial structure and function. The aim of this study was to investigate the relationship between mitofilin and LVH in HD patients. A total of 98 HD patients and 32 healthy controls were included in the study. Serum N-terminal proBNP (NT-proBNP), endothelin-1 (ET-1), and atrial natriuretic peptide (ANP) were examined. The protein level of mitofilin and the mitochondrial DNA (mtDNA) copy number were estimated in peripheral blood mononuclear cells (PBMCs). The left ventricle mass index (LVMI) was evaluated in all participants, and the interaction between these variables and the LVMI was assessed. The LVMI was positively correlated with the NT-proBNP, ET-1, and ANP levels, and it was negatively correlated with mtDNA copy number and mitofilin levels. Multiple regression analysis showed that the NT-proBNP, ET-1, and ANP levels as well as mitofilin levels and mtDNA copy number were associated with the LVMI. Although further research of these associations is needed, this result suggests that LVH may affect the levels of mitofilin in HD patients.

Topics: Adult; Atrial Natriuretic Factor; Biomarkers; Cross-Sectional Studies; DNA, Mitochondrial; Echocardiography; Endothelin-1; Female; Heart Ventricles; Humans; Hypertrophy, Left Ventricular; Kidney Failure, Chronic; Male; Middle Aged; Mitochondrial Proteins; Muscle Proteins; Natriuretic Peptide, Brain; Peptide Fragments; Renal Dialysis; Risk Factors

To investigate the effects of different drugs on systolic blood pressure (SBP) and left ventricular hypertrophy (LVH) in spontaneously hypertensive rats under cold stress.. A total of 40 male spontaneously hypertensive rats aged 10 weeks (160~200 g) were given adaptive feeding for 7 days at a temperature of 20±1°C and then randomly divided into control group, cold stress group, metoprolol group, amlodipine group, and benazepril group, with 8 rats in each group. SBP, body weight, and heart rate were measured once a week. After the rats were sacrificed by exsanguination, left ventricular weight (LVW) was measured, and left ventricular weight index (LVWI; mg/g) was calculated. Radioimmunoassay was used to measure the concentrations of endothelin-1 (ET-1) and angiotensin-II (Ang-II) in plasma and myocardium, and the chemical method was used to measure the concentrations of nitric oxide (NO) in plasma and myocardium. RT-PCR was used to measure the mRNA expression of endothelin-A receptor.. Compared with the cold stress group, all medication groups showed significant reductions in SBP since week 5 (P<0.05). The cold stress group showed a significant increase in LVWI compared with the control group (3.38±0.27 mg/g vs 2.89±0.19 mg/g, P<0.05). The amlodipine group showed a significant reduction in LVWI compared with the cold stress group (2.98±0.28 mg/g vs 3.38±0.27 mg/g, P<0.05). The cold stress group showed a significant reduction in plasma NO concentration compared with the control group (104.9±19.5 μmol/L vs 129.3±17.8 μmol/L, P<0.05) ; compared with the cold stress group, all the medication groups showed significant increases in blood NO concentration (P<0.05). The cold stress group showed a significant increase in myocardial ET-1 concentration compared with the control group (6.3±1.5 pg/100 mg vs 4.5±1.9 pg/100 mg, P<0.05) ; compared with the cold stress group, the amlodipine group showed a significant reduction in myocardial ET-1 concentration (4.4±1.0 pg/100 mg vs 6.3±1.5 pg/100 mg, P<0.05). The cold stress group had significantly higher mRNA expression of endothelin-A receptor than the control group (0.86±0.23 vs 0.45±0.16, P<0.01) ; compared with the cold stress group, the amlodipine group showed a significant reduction in the mRNA expression of endothelin-A receptor (0.41±0.14 vs 0.86±0.23, P<0.01).. Amlodipine can reduce the increase in SBP and inhibit LVH in spontaneously hypertensive rats under cold stress.

Topics: Angiotensin II; Animals; Benzazepines; Blood Pressure; Cold Temperature; Endothelin-1; Hypertension; Hypertrophy, Left Ventricular; Male; Myocardium; Rats; Rats, Inbred SHR; Stress, Physiological

Despite the increasing prevalence of heart failure with preserved ejection fraction (HFpEF) in humans, there remains no evidence-based therapies for HFpEF. Endothelin-1 (ET-1) antagonists are a possibility because elevated ET-1 levels are associated with adverse cardiovascular effects, such as arterial and pulmonary vasoconstriction, impaired left ventricular (LV) relaxation, and stimulation of LV hypertrophy. LV hypertrophy is a common phenotype in HFpEF, particularly when associated with hypertension.. In the present study, we found that ET-1 levels were significantly elevated in patients with chronic stable HFpEF. We then sought to investigate the effects of chronic macitentan, a dual ET-A/ET-B receptor antagonist, on cardiac structure and function in a murine model of HFpEF induced by chronic aldosterone infusion. Macitentan caused LV hypertrophy regression independent of blood pressure changes in HFpEF. Although macitentan did not modulate diastolic dysfunction in HFpEF, it significantly reduced wall thickness and relative wall thickness after 2 weeks of therapy. In vitro studies showed that macitentan decreased the aldosterone-induced cardiomyocyte hypertrophy. These changes were mediated by a reduction in the expression of cardiac myocyte enhancer factor 2a. Moreover, macitentan improved adverse cardiac remodeling, by reducing the stiffer cardiac collagen I and titin n2b expression in the left ventricle of mice with HFpEF.. These findings indicate that dual ET-A/ET-B receptor inhibition improves HFpEF by abrogating adverse cardiac remodeling via antihypertrophic mechanisms and by reducing stiffness. Additional studies are needed to explore the role of dual ET-1 receptor antagonists in patients with HFpEF.

Topics: Aged; Animals; Case-Control Studies; Collagen Type I; Connectin; Diastole; Echocardiography; Endothelin A Receptor Antagonists; Endothelin B Receptor Antagonists; Endothelin-1; Female; Heart; Heart Failure; Humans; Hypertrophy; Hypertrophy, Left Ventricular; In Vitro Techniques; Male; MEF2 Transcription Factors; Mice; Middle Aged; Myocytes, Cardiac; Pyrimidines; RNA, Messenger; Stroke Volume; Sulfonamides; Ventricular Dysfunction, Left; Ventricular Remodeling

Cardiac valve calcification (CVC) and left ventricular (LV) alterations are frequent complication in end-stage renal disease (ESRD). We determined the prevalence of CVC and LV hypertrophy (LVH) in ESRD patients before renal replacement therapy and 12 months after peritoneal dialysis (PD).. A prospective longitudinal of 50 incident PD patients was studied. Demographic and clinical data were recorded and blood assayed at baseline and after 1-year of follow-up. CVC and LVH were evaluated by M-mode two-dimensional echocardiography.. CVC of the mitral and aortic valves and of both valves were noted in 30, 18 and 10% of patients, respectively. After 12 months of PD regimen, 20% patients had aortic, 24% mitral and 8% had calcification of both valves. After one year of PD, LVH was 62 and 36% in patients with and without CVC, respectively (p < 0.05). Endothelin-1 is an independent predictor of CVC at the baseline, while nitric oxide is inversely an independent predictor at the end of follow-up.. CVC is associated with LVH in PD patients. These findings identified a potential role for monitored markers to be incorporated into therapeutic strategies aimed at detection and treatment of cardiovascular complications and prevention strategies.

Topics: Adult; Aged; Aorta; Biomarkers; Calcinosis; Echocardiography; Endothelin-1; Female; Heart Valve Diseases; Humans; Hypertrophy, Left Ventricular; Kidney Failure, Chronic; Logistic Models; Male; Middle Aged; Mitral Valve; Peritoneal Dialysis; Prospective Studies; Young Adult

Left ventricular hypertrophy is the most common structural cardiac alteration in chronic dialysis patients. The aim of this study was to determine the possible association of endotelin-1 (ET-1) and nitric oxide (NO) with parameters of echocardiography in order to assess their participation in left ventricular (LV) remodeling in patients on peritoneal dialysis (PD).. This prospective longitudinal study included 40 PD patients. Serum levels of ET-1 and NO baseline and after 12 months of PD treatment were measured and compared with echocardiography parameters done at the same time of PD treatment. Linear regression analysis was used to detect independent correlations of variables.. Mean ET-1 serum concentration decreased significantly after 12 months of PD treatment compared to baseline values (p < 0.01). NO serum concentration increased significantly 12 months after treatment compared to baseline values (p < 0.01). Left ventricular hypertrophy (LVH) was observed in 72.5% of patients at baseline with significant reduction in LV mass index after 12 months of PD treatment (p < 0.001). On linear regression analysis serum concentration of ET-1 was independent predictors of LV mass index, as well as NO at the end of observed period.. According to our data ET-1 and NO are independently related to the process of left ventricular remodeling in PD patients.

Topics: Adult; Aged; Biomarkers; Endothelin-1; Endothelium, Vascular; Humans; Hypertrophy, Left Ventricular; Kidney Failure, Chronic; Male; Middle Aged; Nitric Oxide; Peritoneal Dialysis; Prospective Studies; Regression Analysis; Ultrasonography; Ventricular Remodeling

Dioscorea opposita Thunb. (Huai Shan Yao, DOT), a common staple food in China, has been used for more than 2000 years in traditional Chinese medicine (TCM) to treat different systemic diseases including hypertension. The objective of this study was to investigate the possible antihypertensive effects of the aqueous extract of (DOT) in renovascular hypertensive rats as well as the mechanism in reducing blood pressure.. The two-kidney one-clip (2K1C) Goldblatt model of renovascular hypertension was used in Wistar rats. Rats with captopril, low-dose DOT and high-dose DOT treated 2K1C groups for 6 weeks. The blood pressure, cardiac mass index (heart weight/body weight), plasma level of angiotensin-II (Ang-II), endothelin-1(ET-1), superoxide dismutase (SOD) and malondialdehyde (MDA) were evaluated.. DOT significantly reduced mean systolic and diastolic blood pressure after treatment. DOT also significantly increased plasma SOD activity but decreased plasma MDA concentration. Renal function was improved with captopril and DOT. DOT reduced plasma Ang-II activity and plasma ET concentration. They couldalso significantly reduce the left ventricular hypertrophy and cardiac mass index.. Our results suggest that DOT may have an antihypertensive effect on hypertension by inhibit ET-converting enzyme and antioxidant activity, which warrant further exploration.

Topics: Angiotensin II; Animals; Antihypertensive Agents; Antioxidants; Blood Pressure; Captopril; China; Dioscorea; Drugs, Chinese Herbal; Endothelin-1; Heart; Hypertension; Hypertension, Renovascular; Hypertrophy, Left Ventricular; Kidney; Male; Malondialdehyde; Oxidative Stress; Phytotherapy; Rats, Sprague-Dawley; Rats, Wistar; Superoxide Dismutase

The purpose of this study was to determine endothelin (ET)-1 and nitric oxide (NO) serum concentration levels at baseline and after 1 year of peritoneal dialysis (PD) treatment. A further aim was to evaluate the association between ET-1 and NO with parameters of echocardiography and the common carotid artery (CCA) ultrasound, and to assess their impact on cardiovascular remodeling. We also aimed to evaluate the influence of dialysis adequacy and residual renal function (RRF) on cardiovascular remodeling.. This study included 40 PD patients in whom we measured serum ET-1 and NO concentrations, echocardiography and CCA ultrasound parameters.. ET-1 decreased and NO serum concentration levels increased (p < 0.01) after 12 months of PD treatment compared to baseline values. Left ventricular (LV) hypertrophy was observed in 77.5% of patients at baseline with significant reduction in LV mass index (LVMI), CCA intima media thickness (IMT) and plaque score after 12 months of PD treatment (p < 0.001). The dialysis adequacy and RRF were significantly associated with LVMI and CCA IMT after 12 months on PD.. In our study, ET-1 significantly decreased while NO increased during PD treatment and both were independently related to the cardiovascular remodeling parameters in PD patients.

Topics: Adult; Aged; Biomarkers; Carotid Artery Diseases; Diabetes Mellitus, Type 2; Endothelin-1; Female; Follow-Up Studies; Humans; Hypertrophy, Left Ventricular; Kidney Failure, Chronic; Male; Middle Aged; Nitric Oxide; Peritoneal Dialysis; Prospective Studies; Ultrasonography; Ventricular Remodeling

To investigate the role of endothelial dysfunction on left ventricular remodeling in patients with chronic kidney disease and to evaluate the correlation between endothelial dysfunction and left ventricular remodeling.. Seventy-three patients with chronic kidney disease as study-group and thirty healthy volunteers as control-group were enrolled in the present study. All patients in both groups had echocardiography examination. The concentration of endothelin-1, nitric oxide, and inducible nitric oxide synthase of serum of all patients and healthy volunteers was measured. The incidence of cardiac structural abnormalities in patients with chronic kidney disease, and the relationship between endothelial dysfunction and cardiac structural abnormalities were analyzed.. The incidence of left ventricular hypertrophy, left ventricular concentric remodeling, and left ventricular systolic dysfunction was 65%, 8.33%, and 16.67%, respectively. The level of endothelin-1 and nitric oxide increased in study-group, and the concentration of inducible nitric oxide synthase decreased. There was significant positively relationship between plasma endothelin-1 and left ventricular mass index, interventricular septal thickness, left ventricular diastolic diameter. There was negatively relationship between the level of serum nitric oxide and the maximum flow velocity at the mitral in left ventricular diastolic stage. There was not any correlation between inducible nitric oxide synthase with left ventricular remodeling.. The results showed that there was a higher incidence of left ventricular hypertrophy in patients with chronic kidney disease. Endothelin-1 and nitric oxide played an important role on the development of left ventricular hypertrophy.

Topics: Adult; Biomarkers; Endothelin-1; Endothelium, Vascular; Female; Humans; Hypertrophy, Left Ventricular; Male; Middle Aged; Nitric Oxide Synthase Type II; Renal Insufficiency, Chronic; Ventricular Remodeling

This study was conducted to study left ventricular hypertrophy (LVH), diastolic dysfunction, pulse pressure (PP), and plasma endothelin (ET)-1 level in amateur marathon runners with an exaggerated blood pressure response (EBPR) to exercise. The study participants included normotensive marathon runners (NM, n = 15), EBPR marathon runners (EBPR, n = 17), normotensive sedentary individuals (CON, n = 13), and hypertensive patients (HTN, n = 14). An integrated M-mode/2-dimensional echocardiographic analysis was performed. Plasma ET-1 levels at resting were measured using a commercial ELISA kit. LV wall thickness and end-diastolic dimensions as well as LV mass index (LVMI) were higher in EBPR than in CON. There were no differences in systolic function among the groups. Analysis of diastolic function, such as lower Em and higher E/Em ratio on TDI, showed a worse relaxation pattern in EBPR. Despite LVH, NM subjects showed no abnormality of LV diastolic dysfunction. HTN subjects in the early stage of their disease showed a slightly modified LV structural and diastolic function, but there was no statistical difference compared with CON. The E/Em ratio was significantly correlated with PP and LVMI. LVMI was significantly correlated with PP. There was a significant difference in plasma ET-1 concentration between marathon runners and hypertensive subjects. We demonstrated that marathon runners with EBPR showed an increase in LVMI and diastolic dysfunction more than HTN subjects in the early stage. PP was significantly related to these two variables. Caution should be exercised when connecting LVH and diastolic dysfunction with plasma ET-1 concentration in all marathon runners.

Topics: Adult; Athletes; Blood Pressure; Cardiomegaly, Exercise-Induced; Diastole; Endothelin-1; Humans; Hypertension; Hypertrophy, Left Ventricular; Male; Middle Aged; Running; Sedentary Behavior; Ultrasonography

The objective of this article is to assess the effects of nebivolol on resistant vascular reactivity, ventricular hypertrophy and the renin-angiotensin system in spontaneously hypertension rats (SHR).. Rats were divided into: SHR treated with nebivolol (8 mg/kg, i.g.)/atenolol(80 mg/kg, i.g.); SHR control group; normotensive Wistar-Kyoto (WKY) control group. Vascular responses to KCl, noradrenaline (NA), endothelin-1 (ET-1), angiotensin II (Ang II), acetylcholine (ACh) and sodium nitroprusside (SNP) were tested on the femoral and renal artery. Left ventricle weight/body weight ratio (LVW/BW) was measured. Ang II and angiotensin-converting enzyme (ACE) activity in plasma and the left ventricle were determined. Plasma renin activity (PRA) was quantified.. Systolic blood pressure was decreased after nebivolol treatment in SHR. Compared with WKY, the contractions to KCl, NA, Ang II and ET-1 were increased in SHR while the relaxation to ACh was impaired. LVW/BW was higher in SHR. Levels of Ang II and ACE activity in plasma and the left ventricle were increased in SHR, but PRA was similar in these groups. Compared with atenolol, nebivolol markedly improved resistant vascular reactivity and decreased LVW/BW and Ang II. But nebivolol had no influence on ACE activity and PRA in SHR.. Nebivolol treatment improved resistant arterial reactivity and reduced left ventricular hypertrophy and Ang II in SHR.

Topics: Acetylcholine; Angiotensin II; Animals; Benzopyrans; Blood Pressure; Body Weight; Endothelin-1; Ethanolamines; Femoral Artery; Hypertrophy, Left Ventricular; In Vitro Techniques; Male; Nebivolol; Nitroprusside; Norepinephrine; Rats; Rats, Inbred SHR; Renal Artery; Renin-Angiotensin System; Systole; Vascular Resistance

Endothelin-1 promotes cardiomyocyte hypertrophy by inducing changes in gene expression. Immediate early genes including Atf3 (activating transcription factor 3), Egr1 (early growth response 1) and Ptgs2 (prostaglandin-endoperoxide synthase 2) are rapidly and transiently up-regulated by endothelin-1 in cardiomyocytes. Atf3 regulates the expression of downstream genes and is implicated in negative feedback regulation of other immediate early genes. To identify Atf3-regulated genes, we knocked down Atf3 expression in cardiomyocytes exposed to endothelin-1 and used microarrays to interrogate the transcriptomic effects. The expression of 23 mRNAs (including Egr1 and Ptgs2) was enhanced and the expression of 25 mRNAs was inhibited by Atf3 knockdown. Using quantitative PCR, we determined that knockdown of Atf3 had little effect on up-regulation of Egr1 mRNA over 30 min, but abolished the subsequent decline, causing sustained Egr1 mRNA expression and enhanced protein expression. This resulted from direct binding of Atf3 to the Egr1 promoter. Mathematical modelling established that Atf3 can suffice to suppress Egr1 expression. Given the widespread co-regulation of Atf3 with Egr1, we suggest that the Atf3-Egr1 negative feedback loop is of general significance. Loss of Atf3 caused abnormal cardiomyocyte growth, presumably resulting from the dysregulation of target genes. The results of the present study therefore identify Atf3 as a nexus in cardiomyocyte hypertrophy required to facilitate the full and proper growth response.

Topics: Activating Transcription Factor 3; Animals; Animals, Newborn; Base Sequence; Cells, Cultured; Cyclooxygenase 2; Early Growth Response Protein 1; Endothelin-1; Feedback, Physiological; Gene Targeting; Hypertrophy, Left Ventricular; Molecular Sequence Data; Myocytes, Cardiac; Rats; Rats, Sprague-Dawley; Transcriptome; Up-Regulation

Endothelin-1 (ET-1), a circulating vasoactive peptide with potent vasoconstricting and mitogenic properties, may contribute to target-organ damage in hypertension. We investigated whether plasma levels of C-terminal pro-endothelin-1 (CT-pro-ET-1) are associated with left ventricular (LV) mass and aortic root diameter in African-American adults with hypertension. Plasma CT-pro-ET-1 was measured by an immunoluminometric assay in 1041 African Americans (65±9 years, 72% women) with hypertension. LV mass and aortic root diameter were measured according to the American Society of Echocardiography guidelines, and LV mass was indexed by height to the power 2.7 (LVMi). Multivariable regression analyses were used to assess whether plasma CT-pro-ET-1 was associated with LVMi and aortic root diameter, independent of potential confounding variables. Plasma CT-pro-ET-1 was modestly correlated with LVMi (r=0.21, P<0.0001) and aortic root diameter (r=0.09, P=0.004). In separate multivariable regression models that adjusted for age, sex, body mass index, total and high-density lipoprotein cholesterol, smoking history, diabetes, history of myocardial infarction or stroke, and blood pressure-lowering medication and statin use, log CT-pro-ET-1 was significantly associated with greater LVMi (P=0.001) and larger aortic root diameter (P=0.006). CT-pro-ET-1 is independently associated with LVMi and aortic root diameter and may be a marker of target-organ damage in African-Americans adults with hypertension.

Topics: Aged; Aortic Valve; Biomarkers; Black or African American; Confounding Factors, Epidemiologic; Echocardiography, Doppler; Endothelin-1; Female; Heart Ventricles; Humans; Hypertension; Hypertrophy, Left Ventricular; Luminescent Measurements; Male; Middle Aged; Peptide Fragments; Regression Analysis; Risk Factors; United States

Hyperuricemia is associated with cardiovascular disease, but it is usually considered a marker rather than a risk factor. Previous studies using uric acid-lowering drugs in normouricemic animals are not suitable to answer the effect of hyperuricemia on ventricular remodeling after myocardial infarction. The purpose of this study was to determine whether hyperuricemia adversely affects ventricular remodeling in infarcted rats with elevated uric acid. Male Wistar rats aged 8 wk were randomly assigned into either vehicle, oxonic acid, oxonic acid + allopurinol, oxonic acid + benzbromarone, oxonic acid + ABT-627, or oxonic acid + tempol for 4 wk starting 24 h after ligation. Postinfarction was associated with increased oxidant production, as measured by myocardial superoxide, isoprostane, xanthine oxidase activity, and dihydroethidium staining. Compared with normouricemic infarcted rats, hyperuricemic infarcted rats had a significant increase of superoxide production (1.7×) and endothelin-1 protein (1.2×) and mRNA (1.4×) expression, which was associated with increased left ventricular dysfunction and enhanced myocardial hypertrophy and fibrosis. These changes were all prevented by treatment with allopurinol. For similar levels of urate lowering, the uricosuric agent benzbromarone had no effect on ventricular remodeling. In spite of equivalent hyperuricemia, the ability of both ABT-627 and tempol to attenuate ventricular remodeling suggested involvement of endothelin-1 and redox pathways. Hyperuricemia is associated with unfavorable ventricular remodeling probably through a superoxide and endothelin-1-dependent pathway. Uric acid lowering without inhibition of superoxide and endothelin-1 may not have an effect on remodeling. Chronic administration of allopurinol, ABT-627, and tempol is associated with attenuated ventricular remodeling.

Topics: Allopurinol; Analysis of Variance; Animals; Antioxidants; Atrasentan; Biomarkers; Cyclic N-Oxides; Dinoprost; Disease Models, Animal; Endothelin A Receptor Antagonists; Endothelin-1; Fibrosis; Gout Suppressants; Hypertrophy, Left Ventricular; Hyperuricemia; Isoprostanes; Male; Myocardial Infarction; Myocardium; Oxidative Stress; Pyrrolidines; Rats; Rats, Wistar; Receptor, Endothelin A; RNA, Messenger; Spin Labels; Superoxides; Time Factors; Up-Regulation; Uric Acid; Ventricular Dysfunction, Left; Ventricular Function, Left; Ventricular Remodeling; Xanthine Oxidase

Coronary vascular dysfunction has been observed in several models of heart failure (HF). Recent evidence indicates that exercise training is beneficial for patients with HF, but the precise intensity and underlying mechanisms are unknown. Left ventricular (LV) hypertrophy can play a significant role in the development of HF; therefore, the purpose of this study was to assess the effects of low-intensity interval exercise training on coronary vascular function in sedentary (HF) and exercise trained (HF-TR) aortic-banded miniature swine displaying LV hypertrophy. Six months postsurgery, in vivo coronary vascular responses to endothelin-1 (ET-1) and adenosine were measured in the left anterior descending coronary artery. Baseline and maximal coronary vascular conductance were similar between all groups. ET-1-induced reductions in coronary vascular conductance (P < 0.05) were greater in HF vs. sedentary control and HF-TR groups. Pretreatment with the ET type A (ET(A)) receptor blocker BQ-123 prevented ET-1 hypersensitivity in HF animals. Whole cell voltage clamp was used to characterize composite K(+) currents (I(K(+))) in coronary smooth muscle cells. Raising internal Ca(2+) from 200 to 500 nM increased Ca(2+)-sensitive K(+) current in HF-TR and control, but not HF animals. In conclusion, an ET(A)-receptor-mediated hypersensitivity to ET-1, elevated resting LV wall tension, and decreased coronary smooth muscle cell Ca(2+)-sensitive I(K(+)) was found in sedentary animals with LV hypertrophy. Low-intensity interval exercise training preserved normal coronary vascular function and smooth muscle cell Ca(2+)-sensitive I(K(+)), illustrating a potential mechanism underlying coronary vascular dysfunction in a large-animal model of LV hypertrophy. Our results demonstrate the potential clinical impact of exercise on coronary vascular function in HF patients displaying pathological LV hypertrophy.

Topics: Animals; Blood Pressure; Capillaries; Cardiotonic Agents; Coronary Circulation; Coronary Disease; Coronary Vessels; Dobutamine; Endothelin A Receptor Antagonists; Endothelin-1; Heart Rate; Hypertrophy, Left Ventricular; In Vitro Techniques; Male; Muscle, Smooth, Vascular; Myocardial Contraction; Peptides, Cyclic; Physical Conditioning, Animal; Potassium Channels, Calcium-Activated; Receptor, Endothelin A; Swine; Swine, Miniature

We have previously reported gender differences in ventricular remodeling and development of heart failure using the aortocaval fistula model of chronic volume overload in rats. In contrast to males, female rats exhibited no adverse ventricular remodeling and less mortality in response to volume overload. This gender-specific cardioprotection was lost following ovariectomy and was partially restored using estrogen replacement. However, it is not known if estrogen treatment would be as effective in males. The purpose of this study was to evaluate the structural and functional effects of estrogen in male rats subjected to chronic volume overload. Four groups of male rats were studied at 3 days and 8 wk postsurgery as follows: fistula and sham-operated controls, with and without estrogen treatment. Biochemical and histological studies were performed at 3 days postsurgery, with chronic structural and functional effects studied at 8 wk. Measurement of systolic and diastolic pressure-volume relationships was obtained using a blood-perfused isolated heart preparation. Both fistula groups developed significant ventricular hypertrophy after 8 wk of volume overload. Untreated rats with fistula exhibited extensive ventricular dilatation, which was coupled with a loss of systolic function. Estrogen attenuated left ventricular dilatation and maintained function in treated rats. Estrogen treatment was also associated with a reduction in oxidative stress and circulating endothelin-1 levels, as well as prevention of matrix metalloproteinase-2 and -9 activation and breakdown of ventricular collagen in the early stage of remodeling. These data demonstrate that estrogen attenuates ventricular remodeling and disease progression in male rats subjected to chronic volume overload.

Topics: Animals; Collagen; Disease Models, Animal; Disease Progression; Endothelin-1; Estradiol; Estrogens; Hypertrophy, Left Ventricular; Male; Mast Cells; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Oxidative Stress; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha; Ventricular Remodeling

While calreticulin has been shown to be critical for cardiac development, its role in cardiac pathology is unclear. Previous studies have shown the detrimental effects on the heart of sustained germline calreticulin overexpression, yet without calreticulin, the heart does not develop normally. Thus, carefully balanced calreticulin levels are required for the heart to develop and to function properly into adulthood. But what happens to calreticulin levels, and how is this regulated, during cardiac hypertrophy, during which the fetal gene program is reactivated, at least partially? Our working hypothesis was that c-Src, a kinase whose activity we previously found to be correlated with calreticulin expression, was involved with calreticulin in regulating the response to hypertrophic signals. Thus, we subjected adult mice to transverse aortic constriction to induce left ventricular hypertrophy. We found that aortic constriction caused calreticulin levels to increase, whereas those of c-Src fell with longer constriction time. We also examined the ability of embryonic stem cell-derived cardiomyocytes to respond to soluble hypertrophic agonists. Endothelin-1 treatment caused a significantly greater cell area increase of calreticulin-null cardiomyocytes, which had higher c-Src activity, compared with wild-type cells. c-Src inhibition abolished this difference. Greater c-Src activity may explain the efficacy with which calreticulin-null cells are able to induce the hypertrophic program, while cells containing calreticulin may be able to attenuate the hypertrophic response as a result of decreased c-Src activity. Thus, calreticulin may have a protective effect on the heart in the face of cardiac hypertrophy.

Topics: Animals; Aorta; Calreticulin; Cardiomegaly; Constriction, Pathologic; Embryo, Mammalian; Endothelin-1; Gene Expression Regulation; Heart Ventricles; Hemodynamics; Hypertrophy, Left Ventricular; Male; Mice; Mice, Inbred C57BL; Myocytes, Cardiac; Organ Size; Phenylephrine; Pressure; Signal Transduction; Solubility; src-Family Kinases

Pulmonary hypertension is associated with reduced nitric oxide bioavailability and early mortality in sickle cell disease (SCD). We previously demonstrated that placenta growth factor (PlGF), an angiogenic factor produced by erythroid cells, induces hypoxia-independent expression of the pulmonary vasoconstrictor endothelin-1 in pulmonary endothelial cells. Using a lentivirus vector, we simulated erythroid expression of PlGF in normal mice up to the levels seen in sickle mice. Consequently, endothelin-1 production increased, right ventricle pressures increased, and right ventricle hypertrophy and pulmonary changes occurred in the mice within 8 weeks. These findings were corroborated in 123 patients with SCD, in whom plasma PlGF levels were significantly associated with anemia, endothelin-1, and tricuspid regurgitant velocity; the latter is reflective of peak pulmonary artery pressure. These results illuminate a novel mechanistic pathway linking hemolysis and erythroid hyperplasia to increased PlGF, endothelin-1, and pulmonary hypertension in SCD, and suggest that strategies that block PlGF signaling may be therapeutically beneficial.

Topics: Adult; Anemia, Sickle Cell; Animals; Cell Line; Endothelin-1; Enzyme-Linked Immunosorbent Assay; Humans; Hypertension, Pulmonary; Hypertrophy, Left Ventricular; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Myocardium; Placenta Growth Factor; Pregnancy Proteins

Liver X receptor (LXR) is a nuclear receptor regulating cholesterol metabolism. Liver X receptor has also been shown to exert anti-proliferative and anti-inflammatory properties. In this study, we evaluated the effect of LXR activation on cardiac hypertrophy in vitro and in vivo.. Treatment with the synthetic LXR agonist T0901317 (T09) attenuated the hypertrophic response of cultured cardiomyocytes to endothelin-1 almost to control levels. siRNA interference showed that this effect was indeed LXR specific. To corroborate these findings in vivo, abdominal aortic constriction (AC) was used as a pressure overload model to induce cardiac hypertrophy in wild-type and LXR-α-deficient (LXR-α(-/-)) mice. In wild-type mice, T09 treatment resulted in a decrease of cardiac wall thickening 4 and 7 weeks after AC. Also, after 7 weeks of AC, mean arterial blood pressure and left ventricular weight/body weight (LVW/BW) ratios were decreased in T09 treated mice. These effects were not observed in LXR-α(-/-) mice, indicating that the beneficial effect of LXR activation on cardiac hypertrophy is attributable to the LXR-α isoform. T09 induced robust cardiac expression of metabolic genes which are downstream of LXR-α, such as SREBP-1c, ABCA1, and ABCG1.. Together these results indicate that LXR exerts salutary effects in cardiac hypertrophy, possibly via metabolic remodelling.

Topics: Analysis of Variance; Animals; Blood Pressure; Disease Models, Animal; Endothelin-1; Heart Ventricles; Hydrocarbons, Fluorinated; Hypertrophy, Left Ventricular; In Vitro Techniques; Liver X Receptors; Mice; Myocytes, Cardiac; Orphan Nuclear Receptors; RNA, Small Interfering; Sulfonamides; Ultrasonography

The study was designed to examine the effects of polydatin on ventricular remodeling induced by isoproterenol in mice and by abdominal aortic banding in rats. Polydatin reduced cardiac weight indexes in mice and rats, lowered the contents of cyclic AMP and angiotensin II in mice. It also decreased the size of cardiomyocyte, the levels of aldosterone, tumor necrosis factor-α, angiotensin II and endothelin-1, reduced ventricular collagen volume and decreased blood pressure in rats. The results demonstrate that polydatin has the beneficial effects on attenuating ventricular remodeling, which are associated with its inhibiting the activation of neurohormone, especially in rennin-angiotensin-aldosterone system.

Topics: Aldosterone; Angiotensin II; Animals; Aorta, Abdominal; Blood Pressure; Cardiovascular Agents; Collagen; Cyclic AMP; Drugs, Chinese Herbal; Endothelin-1; Fallopia japonica; Glucosides; Heart; Hypertrophy, Left Ventricular; Isoproterenol; Male; Mice; Myocytes, Cardiac; Organ Size; Phytotherapy; Rats; Rats, Sprague-Dawley; Renin-Angiotensin System; Stilbenes; Tumor Necrosis Factor-alpha; Ventricular Remodeling

We investigated the effects of iptakalim, a new ATP-sensitive potassium channel (K(ATP)) opener providing endothelial protection, on the progression of cardiac hypertrophy to failure in a rat model of pressure overloading caused by abdominal aortic banding (AAB). Endothelial dysfunction is central to cardiac hypertrophy and failure induced by pressure overload. It would be useful to clarify whether iptakalim could prevent this.. The effects of pressure overload were assessed in male Sprague-Dawley rats 6 weeks after AAB using progression of cardiac hypertrophy to heart failure as the endpoint. The AAB-treated rats had significantly elevated blood pressure, systolic and diastolic cardiac dysfunction, evidence of left ventricular hypertrophy (LVH), and transition to heart failure. LVH was characterized by increases in the ratios of heart and left ventricular weights to body weight, increased myocyte cross-sectional areas, myocardial and perivascular fibrosis, and elevated cardiac hydroxyproline. These could be prevented by treatment with iptakalim at daily oral doses of 1, 3, and 9 mg/kg for 6 weeks. Progression to cardiac failure, demonstrated by increases in relative lung and right ventricular weights, cardiac function disorders and overexpression of atrial and B-type natriuretic peptide mRNA, could also be prevented. The downregulated nitric oxide signalling system was enhanced, whereas the upregulated endothelin signalling system was inhibited, resulting in normalization of the balance between these two systems.. Iptakalim protected the endothelium and prevented progression of cardiac hypertrophy to failure induced by a pressure overload.

Topics: Animals; Aorta, Abdominal; Atrial Natriuretic Factor; Blood Pressure; Cardiovascular Agents; Disease Models, Animal; Disease Progression; Dose-Response Relationship, Drug; Endothelin-1; Endothelium, Vascular; Fibrosis; Heart Failure; Heart Rate; Hydroxyproline; Hypertension; Hypertrophy, Left Ventricular; KATP Channels; Male; Myocardium; Natriuretic Peptide, Brain; Nitric Oxide; Propylamines; Rats; Rats, Sprague-Dawley; Signal Transduction; Time Factors; Ventricular Remodeling

Topics: Animals; Cardiovascular Agents; Disease Progression; Endothelin-1; Endothelium, Vascular; Fibrosis; Heart Failure; Hemodynamics; Humans; Hypertension; Hypertrophy, Left Ventricular; KATP Channels; Mice; Myocardium; Nitric Oxide; Propylamines; Signal Transduction; Ventricular Remodeling

Matrix Gla protein (MGP) expression is increased in cardiac hypertrophy, but the precise mechanisms regulating its expression are unknown. Here we characterized the effect of pressure overload and myocardial infarction in vivo as well as mechanical stretch and hypertrophic agonists in vitro on MGP expression. When angiotensin II (Ang II) was administered by osmotic minipumps, left ventricular (LV) MGP mRNA levels increased significantly from 6 h to 2 weeks, whereas intravenous arginine(8)-vasopressin increased LV MGP mRNA levels within 4 h. During post-infarction remodeling process, MGP mRNA levels were elevated at 24 h (1.3-fold, p<0.05) and the maximal increase was observed at 4 weeks (2.8-fold, p<0.01). Ang II increased MGP mRNA levels 20% (p<0.05) in neonatal rat cardiac myocytes and 40% (p<0.05) in cardiac fibroblasts, whereas endothelin-1 decreased MGP mRNA levels 30% (p<0.01) in myocytes and had no effect in fibroblasts. Cyclic mechanical stretch resulted in reduction of MGP gene expression in both cardiac myocytes and fibroblasts. These results demonstrate that MGP is rapidly upregulated in response to cardiac overload well before the development of LV hypertrophy and post-infarction remodeling process. Our results also suggest that Ang II may be involved in mediating load-induced activation of MGP expression.

Topics: Angiotensin II; Animals; Animals, Newborn; Arginine Vasopressin; Calcium-Binding Proteins; Cells, Cultured; Endothelin-1; Extracellular Matrix Proteins; Fibroblasts; Gene Expression Regulation; Hypertrophy, Left Ventricular; Male; Matrix Gla Protein; Myocardial Contraction; Myocardial Infarction; Myocytes, Cardiac; Rats; Rats, Inbred SHR; Rats, Sprague-Dawley; RNA, Messenger; Stress, Mechanical; Up-Regulation

Inhibition of endothelin-A (ET(A)) receptors has been shown to reduce ventricular electrical abnormalities associated with cardiac failure. In this study, we investigate the effect of ET(A)-receptor inhibition on the development of regional alterations of the transient outward K(+) current (I (to)) in the setting of pressure-induced left ventricular (LV) hypertrophy. Cardiac hypertrophy was induced in female Sprague-Dawley rats by stenosis of the ascending aorta (AS) for 7 days. Treatment with the selective ET(A)-receptor antagonist darusentan (LU135252, 35 mg [kg body weight](-1) day(-1)) was started 1 day before the surgery. AS induced a 46% increase in the relative LV weight (p < 0.001) and caused a significant reduction in I (to) (at +40 mV) in epicardial myocytes (19.5 +/- 1.2 pA pF(-1), n = 32 vs 23.2 +/- 1.2 pA pF(-1), n = 35, p < 0.05). Darusentan further reduced I (to) in AS (15.4 +/- 1.3 pA pF(-1), n = 37, p < 0.05) and sham-operated animals (19.8 +/- 1.6 pA pF(-1), n = 48, ns.). The effects of AS and darusentan on I (to) were significant and independent as tested by two-way analysis of variance. I (to) was not affected in endocardial myocytes. These results indicate that endothelin-1 may exert a tonic effect on the magnitude of I (to) in the epicardial region of the left ventricle but that ET(A)-receptor activation is not necessary for the development of electrical alterations associated with pressure-induced hypertrophy.

Topics: Animals; Aortic Valve Stenosis; Blood Pressure; Disease Models, Animal; Electrophysiology; Endothelin A Receptor Antagonists; Endothelin-1; Female; Gene Expression Regulation; Heart; Hypertrophy, Left Ventricular; Myocytes, Cardiac; Phenylpropionates; Potassium; Potassium Channels; Pyrimidines; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A

Our objective was to analyse the role of endothelin1 gene (EDN1) variation in essential left ventricular hypertrophy (LVH). We searched for EDN1 variants in 145 Spanish patients with an essential form of LVH (not secondary to hypertension, aortic stenosis, or any other disease that could explain the hypertrophy). The five EDN1 coding exons and 1.5 kilobases of the promoter region were analysed through single strand conformation analysis and direct sequencing. We found four nucleotide changes: -1224 C/A (promoter), -131 ins/del A (exon 1, 5'-non-translated sequence), A/G in codon 106 (exon 3, silent), and G/T in codon 198 (exon 5, lys198asn). To determine the association between these polymorphisms and cardiac hypertrophy, we compared the genotype frequencies from these 145 patients with 250 healthy controls. We found a higher frequency of patients homozygous for 198 lys (198 KK) (65% vs. 52%; p = 0.01; OR = 1.76) and for -1224 AA (73% vs. 66%; p = 0.19). Homozygotes for -1224 A + 198 K (AA+KK) were significantly more frequent in patients (62% vs. 45%; p = 0.0007; OR = 2.10; 95% CI = 1.35-3.25). The expression of the -1224 C/A and exon 5 K198N variants was analysed with cells in culture. These in vitro studies showed that these variations did not differ in their expression levels. In conclusion, our work has shown that EDN1 variation, and in particular homozygosity for the -1224A/198K haplotype, is associated with the risk of developing cardiac hypertrophy. However, these EDN1 variants do not affect in vitro gene expression.

Topics: Adolescent; Adult; Amino Acid Substitution; Endothelin-1; Female; Haplotypes; Humans; Hypertrophy, Left Ventricular; Male; Middle Aged; Point Mutation

The aim of the work was to study the maintenance of atrial and brain natriuretic peptide (ANP, BNP) and endothelin-1 (ET-1) in patients with idiopathic arterial hypertension and the relationships between cardiac morphological parameters and concentrations of examined peptides in group of patients with left ventricular hypertrophy (LVH).. Seventy-six patients were enrolled in the study: 21 patients with confirmed idiopathic arterial hypertension (group 1), 18 with idiopathic hypertension and eccentric hypertrophy (group 1a), 14 with idiopathic hypertension and concentric hypertrophy (group 1b), and 23 patients without arterial hypertension, organic heart disease, or chronic respiratory tract diseases (group 2 - control group). All subjects were submitted for echocardiographic evaluation. Posterior wall thickness (PWT), interventricular septum thickness (IVST), left ventricular end-diastolic diameter (LVEDd), left atrium diameter (LAD), left ventricular mass index (LVMI), ejection fraction (EF), fractional shortening (FS), midwall shortening fraction (MWS), and relative wall thickness index (RWT) were studied. Concentrations of ANP(1-28), BNP, and ET-1 were determined with the use of radioimmunological kits (RIA). The obtained results were subjected to statistical analysis.. A considerable increase of ANP and BNP was observed in all patients with hypertension (group 1) in comparison to patients without hypertension (group 2). Significant increases of ANP were found in groups 1a and 1b in comparison to group 1 and 2, as well as considerably increase of BNP in group 1b compared to groups 1, 1a, and 2. In the group of patients with hypertension (group 1), a significant increase in the concentration of ET-1 compared to group 2 was found. However, the concentrations of ET-1 in groups 1 and 2 were not statistically different. Significant differences in concentrations of ET-1 between groups 1a, 1b, and 1 and 2 were seen. Significant correlations were found between concentrations of ANP, BNP, ET-1 and morphological parameters: PWT, IVST, LVMI and RWT. In group 1b, a correlation between concentrations of ANP, BNP, MWS, and LAD was found. The multiple regression analysis showed that RWT independently correlates with concentrations of ANP and BNP, and the concentration of BNP is in closer relation to RWT than ANP. In the case of ET-1, the multiple regression analysis did not show that LVMI or RWT had any independent influence on secretion of ET-1 in patients with idiopathic hypertension and LVH.. Increased concentration of ANP in patients with idiopathic hypertension may point to the coexistence of complications with type of LVH. High concentration of BNP may specifically suggest concentric LVH. This is important - especially if there are difficulties in interpretations of results of other clinical examinations. However, increased concentrations of ET-1 in the plasma of patients with hypertension and LVH should not be treated as an indicator of LVH degree.

Topics: Atrial Natriuretic Factor; Biomarkers; Blood Pressure; Echocardiography, Doppler; Endothelin-1; Female; Heart Atria; Heart Ventricles; Humans; Hypertension; Hypertrophy, Left Ventricular; Male; Middle Aged; Natriuretic Peptide, Brain; Prognosis; Radioimmunoassay; Severity of Illness Index; Stroke Volume

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor characterized to play a role in detection and adaptation to environmental stimuli. Genetic deletion of AhR results in hypertension, and cardiac hypertrophy and fibrosis, associated with elevated plasma angiotensin II (Ang II) and endothelin-1 (ET-1), thus AhR appears to contribute to cardiovascular homeostasis. In these studies, we tested the hypothesis that ET-1 mediates cardiovascular pathology in AhR null mice via ETA receptor activation. First, we determine the time courses of cardiac hypertrophy, and of plasma and tissue ET-1 expression in AhR wildtype and null mice. AhR null mice exhibited increases in heart-to-body weight ratio and age-related expression of cardiac hypertrophy markers, beta-myosin heavy chain (beta-MHC), and atrial natriuretic factor (ANF), which were significant at 2 months. Similarly, plasma and tissue ET-1 expression was significantly elevated at 2 months and increased further with age. Second, AhR null mice were treated with ETA receptor antagonist, BQ-123 (100 nmol/kg/day), for 7, 28, or 58 days and blood pressure, cardiac fibrosis, and cardiac hypertrophy assessed, respectively. BQ-123 for 7 days significantly reduced mean arterial pressure in conscious, catheterized mice. BQ-123 for 28 days significantly reduced the histological appearance of cardiac fibrosis. Treatment for 58 days significantly reduced cardiac mass, assessed by heart weight, echocardiography, and beta-MHC and ANF expression; and reduced cardiac fibrosis as determined by osteopontin and collagen I mRNA expression. These findings establish ET-1 and the ETA receptor as primary determinants of hypertension and cardiac pathology in AhR null mice.

Topics: Angiotensin II; Animals; Blood Pressure; Body Weight; Cardiomegaly; Disease Progression; Echocardiography; Endothelin A Receptor Antagonists; Endothelin-1; Fibrosis; Hypertrophy, Left Ventricular; Mice; Mice, Inbred C57BL; Mice, Knockout; Myocytes, Cardiac; Organ Size; Peptides, Cyclic; Receptor, Endothelin A; Receptors, Aryl Hydrocarbon; RNA, Messenger

Both angiotensin receptor antagonists and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors have been shown to attenuate cardiomyocyte hypertrophy after myocardial infarction. Whether combination treatment may be superior to either drug alone on cardiomyocyte hypertrophy remains unclear. After ligation of the left anterior descending artery, rats were randomized to both, one, or neither of the angiotensin receptor antagonists olmesartan (0.01, 0.1, 1, and 2 mg.kg-1.day-1) and HMG-CoA reductase inhibitor pravastatin (5 mg.kg-1.day-1) for 4 wk. Each drug, when given alone, decreased cardiomyocyte sizes isolated by enzymatic dissociation at the border zone when compared with vehicles. However, compared with either drug alone, combined olmesartan and pravastatin prevent cardiomyocyte hypertrophy to a larger extent, which was further confirmed by downregulation of the left ventricular atrial natriuretic peptide mRNA. The myocardial endothelin-1 levels at the border zone were 6.5-fold higher (P<0.0001) in the vehicle group compared with the sham group, which can be inhibited after pravastatin administration. Combination treatment significantly attenuated cardiomyocyte hypertrophy in a dose-dependent manner, although tissue endothelin-1 levels remained stable in combination groups of different olmesartan doses. Measurements of the arrhythmic score mirrored those of cardiomyocyte hypertrophy. Dual therapy with pravastatin and olmesartan, which produced an additive reduction in cardiomyocyte hypertrophy and cardiac fibrosis after myocardial infarction through different mechanisms, decreases the propensity of the heart to arrhythmogenesis. Pravastatin administration provided favorable ventricular remodeling, probably through decreased tissue endothelin-1 level. In contrast, olmesartan-related attenuated cardiomyocyte hypertrophy is independent of endothelin-1 pathway.

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Dose-Response Relationship, Drug; Drug Therapy, Combination; Endothelin-1; Gene Expression Regulation; Heart Ventricles; Hemodynamics; Hydroxymethylglutaryl CoA Reductases; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertrophy, Left Ventricular; Imidazoles; Male; Myocardial Infarction; Pravastatin; Rats; Rats, Wistar; Receptor, Angiotensin, Type 1; Tetrazoles; Ventricular Remodeling

Statin therapy may be associated with lower mortality in patients with heart failure, but the underlying mechanism of such an association is unknown. We have evaluated the effects of pitavastatin on cardiac function and survival in a rat model of hypertensive heart failure and investigated the molecular mechanism of the observed effects. Dahl salt-sensitive rats fed with high-salt diet from 7 weeks of age developed compensatory left ventricular hypertrophy at 12 weeks and heart failure at 19 weeks. Dahl salt-sensitive rats were treated with either vehicle or pitavastatin (0.3 mg/kg per day) from 7 or 12 weeks. Both early-onset and late-onset pitavastatin treatment reduced left ventricular fibrosis, improved cardiac function, and increased the survival rate apparent at 19 weeks. The increases in the expression levels of hypertrophic, profibrotic, and metalloproteinase genes as well as in gelatinase activities in the heart induced by the high-salt diet were suppressed by pitavastatin treatment. Furthermore, the level of cardiac endothelin-1 was increased in association with the development of heart failure in a manner sensitive to treatment with pitavastatin. Both early and late pitavastatin treatment thus improved cardiac function and survival, with modulation of extracellular matrix remodeling and endothelin-1 signaling possibly contributing to these beneficial effects.

Topics: Animals; Blood Pressure; Cardiac Output, Low; Disease Models, Animal; Endothelin-1; Extracellular Matrix; Gene Expression; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertension; Hypertrophy, Left Ventricular; Lipids; Male; Matrix Metalloproteinases; Protein Prenylation; Quinolines; Rats; Rats, Inbred Dahl; Receptors, Endothelin; Renin-Angiotensin System; Survival Rate; Tissue Inhibitor of Metalloproteinases; Ventricular Remodeling

Epidemiological studies showed that hypercholesterolemia is associated with higher left ventricular mass. Endothelin signaling is activated in hyperlipidemic animals and may contribute to progressive ventricular hypertrophy. Simvastatin has been shown to inhibit endothelin-1. However, the behavior of simvastatin on ventricular hypertrophy in hyperlipidemic animals is not well understood. In this study, we evaluated the hemodynamic, biochemical, and morphological responses to simvastatin in cholesterol-fed (1%) rabbits. The left ventricular weight increased 8 wk after cholesterol feeding compared with that in normocholesterolemic rabbits. Simvastatin at a clinical therapeutic dose (1.2 mg x kg(-1) x day(-1)) significantly decreased left ventricular weight by 14% and left ventricular myocyte sizes by 14% as isolated by enzymatic dissociation. Hypercholesterolemia upregulated ventricular preproendothelin-1 mRNA as assessed by real-time quantitative RT-PCR and elevated production of cardiac endothelin-1 concentration. The increased endothelin-1 responses can be inhibited after simvastatin administration. Left ventricular mass indexed by body weight positively correlated with tissue endothelin-1 levels (P = 0.0003). In Langendorff-perfused rabbit hearts, hyperlipidemia led to significant QT prolongation compared with normocholesterolemia, which can be reversed by administering simvastatin. In contrast, simvastatin-induced beneficial effects were reversed by the addition of mevalonate. The addition of bosentan, a nonspecific endothelin receptor blocker, improved the response in hypercholesterolemic rabbits and did not have additional beneficial effects in simvastatin-treated rabbits. The results of the present study suggest that the antihypertropic and electrocardiographic effects of simvastatin at a clinical therapeutic dose are mediated through inhibition of tissue endothelin-1 expression, which is linked to mevalonate metabolism, and result in an amelioration of cardiomyocyte hypertrophy development by an atherogenic diet.

Topics: Animals; Cholesterol; Electrocardiography; Endothelin-1; Hypercholesterolemia; Hypertrophy, Left Ventricular; Hypolipidemic Agents; Linear Models; Long QT Syndrome; Male; Myocytes, Cardiac; Perfusion; Rabbits; RNA, Messenger; Simvastatin

Endothelin (ET)-1 has been implicated in the development of cardiac hypertrophy. We investigated the effect of pravastatin on development of ventricular hypertrophy in spontaneously hypertensive rats (SHR) and whether the attenuated hypertrophic effect was via reduced ET-1 expression. Normolipidemic SHR were treated with one of the following therapies for 8 wk: vehicle, the nonselective ET receptor antagonists bosentan, pravastatin, mevalonate, hydralazine, or combination of pravastatin + mevalonate from the age of 8 wk at the very early stage of cardiac hypertrophy. Treatment with bosentan and pravastatin significantly decreased left ventricular mass index for body weight and cardiomyocyte sizes isolated by enzymatic dissociation. The myocardial ET-1 levels and preproET-1 mRNA assessed using real-time quantitative RT-PCR were significantly higher (both P < 0.001) in the SHR compared with Wistar-Kyoto rats. The increased tissue ET-1 levels can be inhibited after pravastatin administration. Immunohistochemical analysis confirmed the changes of ET-1. Left ventricular mass index for body weight correlated positively with tissue ET-1 levels (P = 0.0004). A dissociation between the effects of blood pressure and cardiac structure was noted, because pravastatin and hydralazine reduced arterial pressure similarly. Pravastatin-induced effects were reversed by the addition of mevalonate. In conclusion, these results suggest a crucial role of cardiac endothelin system in the early development of ventricular hypertrophy in the SHR. Pravastatin is endowed with cardiac antihypertropic properties that are independent of its hemodynamic and hypolipidemic effects and appear to be related to their capacity to decrease cardiac ET-1 levels, which is linked to mevalonate metabolism.

Topics: Animals; Body Weight; Cardiac Pacing, Artificial; Endothelin-1; Hemodynamics; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertension; Hypertrophy, Left Ventricular; Immunohistochemistry; Male; Myocardium; Organ Size; Pravastatin; Rats; Rats, Inbred SHR; RNA, Messenger; Ventricular Function

Association of polymorphic markers G7831A of ACE gene, Lys198Asn of endothelin-1 (EDN1) gene, and 4a/4b of NOS3 gene with characteristics of structure and function of the left ventricle was studied in 70 (31 men and 39 women) natives of Yakutia with hypertension. Mean age of patients was 48.3+/-0.74 years, duration of hypertension -- 12.4+/-0.99 years; 60 (85.7%), 7 (10%) and 3 (4.3%) patients had III, II and I degree of hypertension, respectively. Polymerase chain reaction was used for identification of alleles of polymorphic markers G7831A of ACE gene, Lys198Asn of EDN1 gene, and 4a/4b of NOS3 gene. Polymorphic marker G7831A of ACE gene was not associated with severity of hypertrophy of left ventricular myocardium as well as with state of systolic and diastolic left ventricular function. Patients with allele Asn of EDN1 gene in the genotype had significantly lower value of peak A integral of trans-mitral blood flow. Patients with allele 4a of NOS3 gene had thicker left ventricular walls, greater left ventricular myocardial mass and mass index.

Topics: Adult; Alanine; Asparagine; Blood Flow Velocity; Endothelin-1; Female; Gene Frequency; Genotype; Glycine; Humans; Hypertension; Hypertrophy, Left Ventricular; Lysine; Male; Middle Aged; Mitral Valve; Nitric Oxide Synthase; Peptidyl-Dipeptidase A; Polymerase Chain Reaction; Polymorphism, Genetic; Russia; Severity of Illness Index

To study the relation of expression change of tumor necrosis factor-alpha (TNF-alpha), angiotensin II (Ang II), and endothelin-1 (ET-1), and the effect of imidapril on myocardial hypertrophy due to overload.. Sixty-three rats were randomly divided into four groups: sham operation (n=15), overload group (n=16), imidapril group (n=16), and Caweidiluo group (n=16). Hypertrophic myocardium was reproduced in rats by constricting abdominal aorta. Blood samples and heart were harvested 12 weeks after aorta constriction, and myocardial hypertrophy index, the contents of Ang II, ET-1 in the myocardium and plasma were determined by radioimmunoassay and TNF-alpha in the myocardium and plasma were determined by enzyme linked immunoadsorbent assay.. Left ventricle showed obvious hypertrophy 12 weeks after operation. The contents of TNF-alpha, Ang II and ET-1 in the myocardium, and the content of TNF-alpha in serum, Ang II and ET-1 in plasma were increased compared with those of controls (all P<0.01). The treatment of imidapril and Caweidiluo could restrain the development of left ventricle hypertrophy after operation, and imidapril decreased the contents of TNF-alpha, Ang II and ET-1 in myocardium compared with overload group (all P<0.01). Imidapril lowered the contents of TNF-alpha in serum, Ang II and ET-1 in plasma, compared with overload group (all P<0.01), but not ET-1. Caweidiluo lowered the contents of TNF-alpha, Ang II and ET-1 in myocardium, the contents of TNF-alpha in serum, Ang II and ET-1 in plasma (all P<0.01) compared with overload group (both P<0.01).. The activation of rennin-angiotensin system (RAS) by over load results to an elevation of TNF-alpha contents in plasma and myocardium, and it is probably one of the major regulatory pathways of myocardial hypertrophy.

Topics: Adrenergic beta-Antagonists; Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Carbazoles; Disease Models, Animal; Endothelin-1; Hypertrophy, Left Ventricular; Imidazolidines; Myocardium; Propanolamines; Random Allocation; Rats; Tumor Necrosis Factor-alpha

Mechanical factors play a key role in activation of cardiac growth factor response in hemodynamic overload, and both cooperate in myocardial remodeling. The present study was performed to investigate whether a different growth factor response is activated in the right and left ventricles in aortocaval fistula and its effects on regional myocardial adaptation. Relations between regional growth factor expression (angiotensin II, insulin-like growth factor-I, and endothelin-1), myocyte shape changes, and collagen deposition were investigated at mRNA and peptide levels in adult pigs after the creation of an aortocaval fistula distal to the renal arteries (n=15) and in sham-operated animals (n=15). The role of angiotensin II was investigated by the administration of angiotensin-converting enzyme inhibitor or angiotensin II receptor antagonist. In the left ventricle, pure volume overload was accompanied by persistent increase of insulin-like growth factor-I mRNA expression, peptide concentration (2.2-fold versus sham at 3 months, P<0.05), and significant increase of myocyte length (+29% at 3 months, P<0.05). Conversely, the mixed pressure-volume overload faced by the right ventricle resulted in significant regional overexpression of all growth factors investigated (angiotensin II, insulin-like growth factor-I, and endothelin-1), with corresponding increase of myocyte diameter and length and collagen deposition (+117% at 3 months). Collagen accumulation in the right ventricle as well as the increase in right ventricular end-diastolic pressure at the 3-month observation were inhibited by angiotensin II antagonism. The left and right ventricles respond differently to aortocaval fistula, and local growth factor expression is closely related to the regional myocardial adaptation.

Topics: Adaptation, Physiological; Angiotensin II; Animals; Cardiac Volume; Collagen; Endothelin-1; Female; Growth Substances; Heart Ventricles; Hemodynamics; Hypertrophy, Left Ventricular; Hypertrophy, Right Ventricular; Insulin-Like Growth Factor I; Male; RNA, Messenger; Swine

Peroxisome proliferator-activated receptor-alpha (PPAR-alpha) is a lipid-activated nuclear receptor that negatively regulates the vascular inflammatory gene response by interacting with transcription factors, nuclear factor-kappaB, and AP-1. However, the roles of PPAR-alpha activators in endothelin (ET)-1-induced cardiac hypertrophy are not yet known.. First, in cultured neonatal rat cardiomyocytes, a PPAR-alpha activator, fenofibrate (10 micromol/L), and PPAR-alpha overexpression markedly inhibited the ET-1-induced increase in protein synthesis. Second, fenofibrate markedly inhibited ET-1-induced increase in c-Jun gene expression and phosphorylation of c-Jun and JNK. These results suggest that this PPAR-alpha activator interferes with the formation and activation of AP-1 protein induced by ET-1 in cardiomyocytes. Third, fenofibrate significantly inhibited the increase of ET-1 mRNA level by ET-1, which was also confirmed by luciferase assay. Electrophoretic mobility shift assay revealed that fenofibrate significantly decreased the ET-1-stimulated or phorbol 12-myristate 13-acetate-stimulated AP-1 DNA binding activity, and the nuclear extract probe complex was supershifted by anti-c-Jun antibody. Fourth, 24 hours after aortic banding (AB) operation, fenofibrate treatment significantly inhibited left ventricular hypertrophy and hypertrophy-related gene expression pattern (ET-1, brain natriuretic peptide, and beta-myosin heavy chain mRNA) in AB rats.. These results suggest that PPAR-alpha activation interferes with the signaling pathway of ET-1-induced cardiac hypertrophy through negative regulation of AP-1 binding activity, partly via inhibition of the JNK pathway in cultured cardiomyocytes. We also revealed that fenofibrate treatment inhibited left ventricle hypertrophy and phenotypic changes in cardiac gene expression in AB rats in vivo.

Topics: Animals; Animals, Newborn; Aorta; Cells, Cultured; Disease Models, Animal; Endothelin-1; Fenofibrate; Genes, fos; Genes, jun; Hypertrophy, Left Ventricular; JNK Mitogen-Activated Protein Kinases; Ligation; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases; Myocytes, Cardiac; Phosphorylation; Protein Processing, Post-Translational; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins c-jun; Rats; Rats, Sprague-Dawley; Receptors, Cytoplasmic and Nuclear; RNA, Messenger; Signal Transduction; Tetradecanoylphorbol Acetate; Transcription Factor AP-1; Transcription Factors

The hypothesis that endothelin (ET) receptor mechanisms are altered during development and progression of left ventricular hypertrophy (LVH) in vivo was tested using spontaneously hypertensive rats (SHRs). Ventricular cardiomyocytes were isolated from SHRs before onset (8 and 12 wk) and during progression (16, 20, and 24 wk) of LVH and compared with age-matched normotensive Wistar-Kyoto (WKY) rats. PreproET-1 mRNA expression was elevated in SHR (P < 0.05) relative to WKY cardiomyocytes at 20-24 wk. ET binding-site density was twofold greater in SHR than WKY cells at 12 wk (P < 0.05) but normalized at 20 wk. ET(B) receptors were detected on SHR cardiomyocytes as early as 8 wk and their affinity increased progressively with age (P < 0.05), whereas ET(B) receptors were not detected on WKY cells until 20 wk. ET-1 stimulated protein synthesis with similar maximum responses between strains (21-30%), in contrast with sarafotoxin 6c, which stimulated protein synthesis in SHR (13-20%) but not WKY cells at 12-20 wk. In SHR but not WKY cells, the ET(B) receptor-selective ligand A-192621 increased protein synthesis progressively with the development of LVH (15% maximum effect). In conclusion, the presence of ET(B) receptors (8-12 wk) coupled with functional responsiveness of SHR cells but not WKY cells to sarafotoxin 6c at 12 wk supports the involvement of ET(B) receptors before the onset of cardiomyocyte hypertrophy, whereas altered ET(B) receptor characteristics during active hypertrophy (16-24 wk) indicate that ET(B) receptor mechanisms may also contribute to disease progression.

Topics: Animals; Binding Sites; Binding, Competitive; Disease Progression; Endothelin-1; Endothelin-3; Hypertrophy, Left Ventricular; Male; Muscle Proteins; Myocardial Contraction; Myocardium; Myocytes, Cardiac; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Receptor, Endothelin B; Viper Venoms

Hypertension is associated with changes in concentrations of vasoactive peptides and procollagen propeptides, but their relationships with left ventricular hypertrophy and cardiac function are unclear.. We measured plasma levels of atrial natriuretic peptide (ANP), its amino terminal propeptide (NT-proANP), B-type natriuretic peptide (BNP), endothelin-1 (ET-1), and serum levels of the aminoterminal propeptide of type I procollagen (PINP) and the aminoterminal propeptide of type III procollagen (PIIINP) and echocardiographic parameters in 97 patients with hypertension in the Anglo-Scandinavian Cardiac Outcomes Trial.. Median values (reference values) of the peptides were: ANP 11.2 (6.9-14.9) pmol/l, NT-proANP 351 (143-311) pmol/l, BNP 1.1 (0.4-7.2) pmol/l, ET-1 8.7 (1.2-5.0) pmol/l, PIIINP 2.8 (1.7-4.2) microg/l and PINP 29 (19-84) microg/l. Plasma BNP levels in patients with left ventricular hypertrophy (1.2 pmol/l) and patients with echocardiographic signs of diastolic dysfunction (1.5 pmol/l) were greater than those in patients without hypertrophy (0.7 pmol/l) and normal diastolic parameters (0.9 pmol/l) (p<0.05). BNP was the only biochemical parameter that independently predicted interventricular septal diastolic diameter (p<0.05), left ventricular mass index (p<0.01) and ratio of the velocity-time integrals of the E and A waves of the mitral inflow in a stepwise logistic regression analysis (p<0.05).. The results show that BNP reflects the remodelling process in hypertension.

Topics: Adult; Atrial Natriuretic Factor; Biomarkers; Case-Control Studies; Diastole; Endothelin-1; Humans; Hypertension; Hypertrophy, Left Ventricular; Middle Aged; Natriuretic Peptide, Brain; Peptide Fragments; Procollagen; Protein Precursors; Ultrasonography; Ventricular Dysfunction, Left

Endothelin-1 (ET-1) is a powerful vasconstrictor peptide implicated in development of essential hypertension and left ventricular hypertrophy. To evaluate the impact of genetic variability of the ET-1 gene on progression of blood pressure (BP) and left ventricular mass (LVM), we conducted individual growth curve modeling for 537 European American and black youths with 12 assessments during a 15-year period. Four common single-nucleotide polymorphisms (SNPs) including T-1370G, +138/ex1 del/ins, T-37/in2C, and Lys198Asn were included in this study. Single SNP analyses showed that individuals with the +138/ex1 ins allele had a borderline significant lower systolic BP (SBP; P=0.072). Furthermore, the -37/in2C allele showed an SBP-lowering effect in males, accounting for 1.6% between-subject variation of SBP (P=0.016). Haplotype analyses in males confirmed the BP-lowering effect of the -37/in2C allele. SBP in individuals homozygous for the del (+138/ex1) -C (-37/in2) haplotype was 3.3 mm Hg lower than those homozygous for the del (+138/ex1) -T (-37/in2) haplotype (P=0.038). For LVM, we observed a significant gene-environment interaction. LVM levels were 20 g higher in carriers versus noncarriers of the -1370G allele in the low socioeconomic status (SES) group only (P=0.004). In summary, our results uncover a sex-specific protective effect of variation in the ET-1 gene on the progression of hypertension risk, and a SES-specific effect on risk of developing left ventricular hypertrophy in multiethnic youth.

Topics: Adolescent; Black People; Blood Pressure; Body Mass Index; Child; Cohort Studies; Endothelin-1; Female; Genotype; Haplotypes; Humans; Hypertension; Hypertrophy, Left Ventricular; Linkage Disequilibrium; Male; Polymorphism, Single Nucleotide; Risk Factors; Sex Factors; Socioeconomic Factors; White People

Endothelin-1 is involved in mechanical load-induced cardiac growth processes; it also has effects on contractility. The interaction of endothelin-1 and the Frank-Starling response is unknown. The present study aimed to characterize the role of endothelin-1 in the regulation of the Frank-Starling response, one of the major mechanisms regulating cardiac contractile force, in both normal and hypertrophied hearts. Nontransgenic rat hearts and hypertrophic hearts of hypertensive double transgenic rats harboring human angiotensinogen and renin genes were studied in a Langendorff isolated heart setup with a liquid-filled balloon inside the left ventricle used to measure contractile parameters. The rats were studied at compensated phase, before showing any signs of heart failure. Compensated hypertrophy in double transgenic rat hearts resulted in improved contractility at a given level of preload when compared with nontransgenic rat hearts. Hearts of both rat lines showed preserved Frank-Starling responses, that is, increased contractile function in response to increased end-diastolic pressure. The mixed endothelin A/B receptor antagonist bosentan attenuated the Frank-Starling response by 53% (P<0.01) in the double transgenic hearts but not in nontransgenic hearts. The diastolic parameters remained unaffected. The left ventricles of the double transgenic rat hearts showed an 82% higher level of endothelin type A receptor mRNA and a 25% higher level of immunoreactive endothelin-1 compared with nontransgenic rat hearts. The type 1 angiotensin II receptor antagonist CV-11974 had no significant effect on contractile function in response to load in either strain. These results show that endogenous endothelin-1 contributes to the Frank-Starling response in hypertrophied rat hearts by affecting systolic performance.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Angiotensinogen; Animals; Animals, Genetically Modified; Benzimidazoles; Biphenyl Compounds; Bosentan; Endothelin Receptor Antagonists; Endothelin-1; Heart Ventricles; Humans; Hypertension; Hypertrophy, Left Ventricular; Male; Myocardial Contraction; Organ Culture Techniques; Rats; Rats, Inbred SHR; Rats, Sprague-Dawley; Receptor, Angiotensin, Type 1; Renin; RNA, Messenger; Stress, Mechanical; Sulfonamides; Tetrazoles

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates toxicity of xenobiotics, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin. Genetic deletion of the AhR leads to cardiac hypertrophy, suggesting a role for the AhR in cardiovascular physiology and disease; however, the pathways involved in the development of cardiac hypertrophy have not been determined. Thus, we investigated the role of (1) pressure overload using indwelling catheters and (2) vasoactive peptides endothelin-1 (ET-1) and angiotensin II (Ang II), assessed by RIA, in the progression of cardiac hypertrophy in AhR-null mice. Histochemical analysis, expression of cardiac hypertrophy marker genes, and echocardiography were used to assess the degree of cardiac hypertrophy. AhR-null mice developed elevated mean arterial pressures (MAP) by 5 months, which was associated with a two- and ninefold increase in plasma ET-1 and Ang II, respectively, compared to wild-type. Captopril-treatment (4 mg/kg) of AhR-null mice from 2 to 5 months of age significantly decreased MAP and plasma Ang II, but did not affect ET-1. Further, captopril improved cardiac function and reduced cardiac hypertrophy as evidenced by reduction in left ventricle mass, left ventricle internal dimension, and molecular cardiac hypertrophy markers. Captopril also decreased fibrosis of the heart and kidney. These findings show that pressure overload is associated with elevated ET-1 and hypertrophic growth of the heart and that cardiac hypertrophy is mediated, in part, by Ang II.

Topics: Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Biomarkers; Captopril; Disease Models, Animal; Echocardiography; Endothelin-1; Genetic Markers; Heart Ventricles; Hypertension; Hypertrophy, Left Ventricular; Mice; Mice, Inbred C57BL; Mice, Knockout; Organ Size; Receptors, Aryl Hydrocarbon; RNA, Messenger; Ventricular Myosins

It is well established that angiotensin-converting enzyme (ACE) inhibitors (ACEI) reduce blood pressure (BP) and hypertrophy of the left ventricle and vessels. The aim of our study was to compare chemically different ACEIs regarding their ability to modulate left ventricular and media hypertrophy, ACE activity and plasma endothelin-1 concentrations in spontaneously hypertensive rats (SHRs).. After establishing equi-effective dose regimes, SHRs were treated (3 months) with captopril, enalapril, fosinopril or ramipril (2 x 25, 10, 20 or 1 mg/kg per day or corresponding 1% doses for studying blood pressure-independent effects).. Systolic blood pressure was reduced in SHRs receiving high doses of captopril, enalapril, fosinopril or ramipril (-61, -54, -35 and -47 mmHg), whereas low doses were ineffective. Left ventricular weight was decreased in animals treated with high doses (captopril/enalapril/fosinopril/ramipril: -17/-19/-17/-19%), but not low doses of agents. Media thickness of thoracal aorta was reduced by administering high doses (captopril/enalapril/fosinopril/ramipril: -31/-32/-27/-26%) and low doses (-16/-22/-22/-19%) of agents. ACE activity was reduced in heart, aorta and kidney of rats treated with high and low doses of all ACE inhibitors, whereby high doses showed more pronounced effects. Plasma endothelin-1 concentrations were not altered. A blood-pressure-ineffective treatment with an AT -antagonist revealed similar effects on cardiovascular hypertrophy.. ACEIs reduce cardiovascular hypertrophy uniformly via an AT -receptor- mediated mechanism, reinforcing the opinion that ACEI effects are indeed class effects. The significance of local renin-angiotensin systems was confirmed by antihypertrophic effects in the aorta that were apparent in the absence of any blood pressure reduction.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Aorta, Thoracic; Blood Pressure; Body Weight; Captopril; Circadian Rhythm; Dose-Response Relationship, Drug; Enalapril; Endothelin-1; Fosinopril; Hypertrophy, Left Ventricular; Male; Peptidyl-Dipeptidase A; Ramipril; Rats; Rats, Inbred SHR

To characterize the cardiac angiotensin and endothelin (ET) system in compensated left ventricular hypertrophy due to long standing arterial hypertension and to assess the role of angiotensin and ET converting enzymes in mediating the observed changes of angiotensin and ET levels, respectively.. We studied the left ventricular renin-angiotensin system (RAS) and ET system in 20-week-old male transgenic hypertensive TG(mREN2)27 rats, a model of the monogenic renin-dependent form of severe hypertension. Age-matched Sprague-Dawley rats served as controls.. TG(mREN2)27 rats exhibited left ventricular hypertrophy without signs of congestion. Transgene overexpression led to an activation of the tissue RAS with increased angiotensin II levels in spite of unchanged angiotensin converting enzyme (ACE) activity and ACE mRNA levels. ET-1 production was markedly increased in TG(mREN2)27 rats indicating that the ET-system was activated. Cardiac ET-1 in TG(mREN2)27 originated most likely from increased preproET-1 production because preproET-1 mRNA levels were increased but ET converting enzyme gene expression and activity were unchanged. Furthermore, ET-1 binding sites were significantly increased in TG(mREN2)27 rats without changes in K(D) values and ET(A)/ET(B) receptor ratios. ET(A) receptor gene expression was not altered whereas ET(B) receptor mRNA levels were up-regulated twofold in TG(mREN2)27 rats suggesting that ET(A) and ET(B) receptor expression may be regulated differentially.. Cardiac ET and angiotensin systems are co-activated in compensated cardiac hypertrophy before onset of heart failure, and thus may be involved in the mechanism by which cardiac remodelling and progression of left ventricular dysfunction occur in TG(mREN2)27 rats.

Topics: Angiotensin II; Animals; Animals, Genetically Modified; Aspartic Acid Endopeptidases; Collagen; Endothelin-1; Endothelin-Converting Enzymes; Hypertension; Hypertrophy, Left Ventricular; Immunohistochemistry; Male; Metalloendopeptidases; Models, Animal; Myocardium; Peptidyl-Dipeptidase A; Rats; Rats, Sprague-Dawley; Receptors, Endothelin; Renin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

The role of load versus angiotensin II (Ang II) and endothelin-1 (ET) in the pathogenesis of hypertensive heart disease is controversial. We sought to determine whether alterations in cardiac structure and function due to hypertension (HTN) were dependent on Ang II or ET activation. Methods and Results-- Bilateral renal wrapping to produce HTN (n=12) or sham surgery (n=6) was performed in adult dogs. Weekly blood pressure, plasma renin activity, Ang II, ET, and catecholamines were measured. Systolic (end-systolic elastance, Ees) and diastolic (tau) function were assessed in sham and HTN dogs at 5 (HTN-5wk) or 12 (HTN-12wk) weeks. Ang II and ET were assayed in the left ventricle (LV) and kidney. Mean arterial pressure was higher in renal wrap dogs at week 1 (*P<0.05 versus controls: 139+/-4* versus 123+/-4 mm Hg), week 5 (174+/-7* versus 124+/-4 mm Hg), and week 12 (181+/-12* versus 124+/-4 mm Hg). LV mass index was increased in HTN-5wk (22%*) and HTN-12wk (39%*). LV fibrosis was increased in HTN-12wk. Ees was preserved in HTN-5wk and HTN-12wk. tau was increased in HTN-5wk (50+/-3* ms) and HTN-12wk (62+/-10* ms) dogs compared with sham (41+/-2 ms). Plasma Ang II, ET, catecholamines, and plasma renin activity were unchanged during the progressive HTN. Ang II and ET in LV and kidney were not different from controls.. Systemic HTN induces LV hypertrophy, myocardial fibrosis, and isolated diastolic dysfunction in the absence of local or systemic activation of Ang II or ET. These findings suggest that load is the prevailing stimulus for the structural and functional changes associated with early hypertensive heart disease.

Topics: Angiotensin II; Animals; Catecholamines; Diastole; Disease Models, Animal; Dogs; Endothelin-1; Heart Ventricles; Hemodynamics; Hypertension; Hypertrophy, Left Ventricular; Kidney; Natriuretic Peptide, Brain; Propranolol; Renin; Systole; Ventricular Dysfunction, Left

In view of their mutual crosstalk, the roles of angiotensin II (Ang II) and endothelin-1 (ET-1) in the myocardium are assumed to be synergistic and supplemental.. In the phase of compensated left ventricular (LV) hypertrophy of Dahl salt-sensitive rats, Ang II peptide and the ACE mRNA in the LV were increased by 1.6- and 3.8-fold, respectively. In contrast, ET-1 peptide and the preproET-1 mRNA remained unchanged. In subsequent congestive heart failure (CHF), Ang II and ACE mRNA did not show further increases. But ET-1 and the mRNA were increased de novo by 5.3- and 4.1-fold, respectively. In ascending aorta-banded rats, the local activations of Ang II and ET-1 also showed a differential time course between LV hypertrophy and CHF. Long-term treatments of Dahl salt-sensitive rats with temocapril (an ACE inhibitor) and with bosentan (a mixed ET receptor blocker) equally improved long-term survival. Temocapril reduced the LV/body weight ratio and ameliorated LV fractional shortening. Conversely, although bosentan equally improved fractional shortening, it did not reduce the increase in LV mass. Combined treatment with these 2 drugs further ameliorated the animal's survival without additional decreases in systolic pressure.. The pathophysiological roles in the myocardium during the transition to CHF differ qualitatively between Ang II and ET-1. Thus, long-term therapy with a combination of ACE inhibition and ET antagonism may provide a new approach for heart failure in humans.

Topics: Angiotensin II; Angiotensinogen; Animals; Antihypertensive Agents; Blood Pressure; Bosentan; Disease Progression; Endothelin-1; Endothelins; Gene Expression Regulation; Heart Failure; Heart Ventricles; Hemodynamics; Hypertrophy, Left Ventricular; Male; Organ Size; Peptidyl-Dipeptidase A; Protein Precursors; Rats; Rats, Inbred Dahl; Rats, Sprague-Dawley; RNA, Messenger; Sulfonamides; Survival Analysis; Thiazepines; Time Factors

The mechanisms controlling the coronary vascular responses of vessels perfusing the left ventricular (LV) myocardium that is hypertrophied from chronic volume overload are unclear. We hypothesised that endothelial function is compromised, and receptor-mediated contraction is exacerbated, in coronary resistance vessels from rabbits with LV hypertrophy compared to controls. The mitral valve of 10 rabbits was damaged surgically to cause mitral regurgitation and chronic volume overload, resulting in LV hypertrophy (LV hypertrophy rabbits). Echocardiographic assessment at 12 weeks verified that mitral regurgitation was present in LV hypertrophy but not sham-operated, weight- and age-matched animals (control rabbits; n = 17). Percentage increases from weeks 0 to 12 in LV cross-sectional area (47 +/- 7 % vs. 2 +/- 8 %), LV volume (47 +/- 14 % vs. 7 +/- 10 %) and LV mass (27 +/- 4 % vs. 3 +/- 6 %), were greater (all P < 0.05) in LV hypertrophy vs. control rabbits, respectively. At 12 weeks, coronary resistance vessel (approximately 130 microm, internal diameter) reactivity was evaluated using wire myography. Endothelium-dependent (i.e. acetylcholine, 10(-8)-10(-5) M) and -independent (i.e. sodium nitroprusside, 10(-9)-10(-4) M) relaxation, and receptor-mediated vasocontraction (i.e. endothelin-1, 10(-11)-10(-7) M) were similar between groups. However, tension development in response to nitric oxide synthase inhibition (10(-6) M N (G)-monomethyl-L-arginine) was greater (P < 0.05) in LV hypertrophy compared to control rabbits. These results indicate that while coronary resistance vessel function is similar between groups, our estimate of basal nitric oxide production is greater in vessels from LV hypertrophy than control rabbits.

Topics: Acetylcholine; Animals; Blood Vessels; Chronic Disease; Coronary Circulation; Endothelin-1; Hyperemia; Hypertrophy, Left Ventricular; Male; Microcirculation; Mitral Valve Insufficiency; Myocardial Contraction; Nitric Oxide; Nitric Oxide Donors; Nitroprusside; Rabbits; Reference Values; Vasodilation; Vasodilator Agents; Ventricular Function, Left

Cardiac troponin T (cTnT) is a highly sensitive marker for the detection of myocardial damage. However, patients maintained on chronic dialysis often have increased serum cTnT concentrations without evidence of acute myocardial injury. The reason for this is unclear. In chronic haemodialysis patients, elevated plasma concentrations of big endothelin-1 (big ET-1) and endothelin-1 (ET-1) have been reported which may be associated with ischaemic heart disease. The aim of the present study was to investigate possible associations between cTnT, big ET-1, ET-1, other cardiac markers and cardiac disease in dialysis patients.. Thirty-six haemodialysis (HD) patients and 26 peritoneal dialysis (PD) patients without symptoms of acute myocardial ischaemia were investigated. In all patients, serum concentrations of cTnT (2nd generation ELISA), cardiac troponin I (TnI) (Opus, Behring), creatine kinase MB (CKMB) mass and creatine kinase (CK) were determined, in HD patients before and after dialysis. Additionally, in HD patients, plasma ET-1 and big ET-1 were measured. In 27 HD patients, left ventricular mass index (LVMI) was determined. Patients with ischaemic heart disease (IHD) were compared with non-IHD patients.. Serum cTnT was elevated (> or =0.10 microg/l) in 20 of 36 HD patients and in eight of 26 PD patients. cTnI was elevated (> or =0.5 microg/l) in four of 62 dialysis patients. HD+PD patients with IHD showed higher cTnT than HD+PD patients without IHD, and ET-1 concentrations were higher in HD patients with than without IHD. In HD patients, there was a positive correlation between cTnT and big ET-1. In HD patients with left ventricular hypertrophy (LVH), serum cTnT, CKMB mass and post-dialysis plasma big ET-1 were higher than in patients with normal LVMI. Furthermore there was a positive correlation between cTnT levels and LVMI.. These findings suggest that circulating cTnT may reflect left ventricular hypertrophy and/or myocardial ischaemia in dialysis patients, and indicate that ET-1 and big ET-1 might be associated with these conditions.

Topics: Adult; Aged; Aged, 80 and over; Creatine Kinase; Endothelin-1; Endothelins; Female; Heart Diseases; Humans; Hypertrophy, Left Ventricular; Isoenzymes; Male; Middle Aged; Myocardial Ischemia; Osmolar Concentration; Peritoneal Dialysis; Protein Precursors; Renal Dialysis; Troponin T; Ultrasonography

In normal hearts, endothelin-1 (ET-1) has been shown to initiate myocyte growth and to modulate cardiac function. However, regulation of the various components of the system and the functional effects of ET-1 in established left ventricular hypertrophy (LVH) are less clear. We thus studied ET-1, ET(A) receptor, and endothelin converting enzyme (ECE-1) mRNA regulation as well as the effects of ET-1 on coronary resistance, LV contractility and relaxation in hypertrophied rat hearts. Cardiac pressure overload, secondary to banding of the ascending aorta, resulted in a transient increase of cardiac ET-1 and ET(A) receptor mRNAs that reached a maximum at 2 days (+75% and +40%, respectively, P<0.05, each). ET-1 mRNA levels reached a second peak at 84 days of pressure overload (+60%, P<0.05), at the later time point in conjunction with elevated ECE-1 mRNA levels (+20%, P<0.05). The functional implications of ET-1 were examined in a study of isolated perfused hearts. Both hearts with established LVH and sham control hearts responded to ET-1 perfusion (10(-1)] to 10(-9) M) with an increase of coronary perfusion pressure (CPP; +85+/-15 and +75+/-8 mm Hg; P<0.001 each) and a slight decrease of LV systolic pressure (LVP; -12+/-9 and -9+/-7 mm Hg; P = NS). In contrast, ET-1 increased LV end-diastolic pressure (LVEDP) only in LVH hearts (+22+/-7 mm Hg, P<0.05 versus baseline and +20+/-7 mm Hg, P<0.05 versus sham). Direct stimulation of protein kinase C mimicked the effects of ET-1, whereas inhibition of this kinase or the Na+ -H+ exchanger blunted the effects of ET-1 on CPP, LVP, and LVEDP. Interestingly, coadministration of the vasodilator and the nitric oxide (NO) donor nitroglycerin not only prevented the increase of CPP and LVEDP, but also uncovered a slight positive inotropic effect of ET-1 in LVH hearts. Thus, the cardiac expression of ET-1, ET(A), and ECE-1 mRNAs displays a distinct pattern during early and advanced cardiac pressure overload. Furthermore, ET-1 mediates a slight depression of systolic, and a profound depression of diastolic, functional parameters in hearts with established LVH, effects that appear to be secondary to ET-1-related coronary vasoconstriction. The data suggest a functional role of the endothelin system in hearts with established pressure overload hypertrophy.

Topics: Amiloride; Animals; Aortic Diseases; Aspartic Acid Endopeptidases; Blood Pressure; Endothelin-1; Endothelin-Converting Enzymes; Enzyme Inhibitors; Hypertrophy, Left Ventricular; In Vitro Techniques; Male; Metalloendopeptidases; Myocardium; Nitroglycerin; Protein Kinase C; Rats; Rats, Wistar; Receptor, Endothelin A; Receptors, Endothelin; Staurosporine

The activation of B(2) receptors by kinins could exert cardioprotective effects in myocardial ischemia and heart failure.. To test whether the absence of bradykinin B(2) receptors may affect cardiac structure and function, we examined the developmental changes in blood pressure (BP), heart rate, and heart morphology of bradykinin B(2) receptor gene knockout (B(2)(-/-)), heterozygous (B(2)(+/-)), and wild-type (B(2)(+/+)) mice. The BP of B(2)(-/-) mice, which was still normal at 50 days of age, gradually increased, reaching a plateau at 6 months (136+/-3 versus 109+/-1 mm Hg in B(2)(+/+), P<0.01). In B(2)(+/-) mice, BP elevation was delayed. At 40 days, the heart rate was higher (P<0.01) in B(2)(-/-) and B(2)(+/-) than in B(2)(+/+) mice, whereas the left ventricular (LV) weight and chamber volume were similar among groups. Thereafter, the LV growth rate of B(2)(-/-) and B(2)(+/-) mice was accelerated, leading at 360 days to a LV weight-to-body weight ratio that was 9% and 17% higher, respectively, than that of B(2)(+/+) mice. In B(2)(-/-) mice, hypertrophy was associated with a marked chamber dilatation (42% larger than that of B(2)(+/+) mice), an elevation in LV end-diastolic pressure (25+/-3 versus 5+/-1 mm Hg in B(2)(+/+) mice, P<0.01), and reparative fibrosis.. The disruption of the bradykinin B(2) receptor leads to hypertension, LV remodeling, and functional impairment, implying that kinins are essential for the functional and structural preservation of the heart.

Topics: Age Factors; Animals; Atrial Natriuretic Factor; Blood Pressure; Cardiomyopathy, Dilated; Disease Models, Animal; Endothelin-1; Fibrosis; Gene Expression; Heart Rate; Heterozygote; Homozygote; Hypertension; Hypertrophy, Left Ventricular; Kallikrein-Kinin System; Male; Mice; Mice, Knockout; Myocardium; Phenotype; Receptor, Bradykinin B2; Receptors, Bradykinin; RNA, Messenger; Sarcomeres

Carvedilol and lacidipine have been shown to exert cardioprotective effects in rat models of chronic hypertension. We investigated their effects in an acute model of pressure overload produced by suprarenal aortic constriction, in which enhanced myocardial production of endothelin-1 could play a crucial role. In the absence of drug treatment, after 1 week, aortic banding provoked an increase in carotid pressure associated with left ventricular hypertrophy (29%; P<0.01). These changes were accompanied by increased myocardial expression of preproendothelin-1 (2.5 times; P<0.05) and skeletal alpha-actin (3.6 times; P<0.05), but the expression of cardiac alpha-actin was not modified. Oral administration of carvedilol at a dose of 30 mg. kg(-1). d(-1) to rats with aortic banding normalized carotid pressure and left ventricular weight as well as preproendothelin-1 and skeletal alpha-actin gene expression. Carvedilol at a lower dose (7.5 mg x kg(-1) x d(-1)) and lacidipine 1 mg x kg(-1) x d(-1) had only moderate and nonsignificant effects on carotid pressure but largely prevented left ventricular hypertrophy (P<0.01) and preproendothelin-1 overexpression (P<0.05). Labetalol (60 mg x kg(-1) x d(-1)) tended to exert similar effects but insignificantly. These results show that the antihypertrophic properties of carvedilol and lacidipine are partly independent of their antihypertensive effects and may be related to their ability to blunt myocardial preproendothelin-1 overexpression. Moreover, carvedilol at a dose of 7.5 mg x kg(-1) x d(-1) did not prevent myocardial overexpression of skeletal alpha-actin, which suggests that, in this model, reexpression of a fetal gene can be activated by pressure overload independently of cardiac hypertrophy.

Topics: Actins; Animals; Antihypertensive Agents; Aortic Diseases; Blood Pressure; Carbazoles; Carotid Arteries; Carvedilol; Constriction, Pathologic; Dihydropyridines; Disease Models, Animal; Endothelin-1; Endothelins; Gene Expression; Heart Rate; Heart Ventricles; Hypertrophy, Left Ventricular; Labetalol; Ligation; Male; Myocardium; Organ Size; Propanolamines; Protein Precursors; Rats; Rats, Sprague-Dawley; Renin; RNA, Messenger

Endothelin-1 (Et-1) is a vasoconstrictor produced by endothelial and vascular smooth muscle cells in response to hypoxia, which induces hypertrophy in cultured cardiac myocytes. We measured plasma Et-1 levels and left ventricular dimensions in 13 patients with sickle cell anemia (SCD) and in 12 African-American controls ages 16-29 years. Endothelin-1 concentrations are significantly higher in SCD subjects than controls (10.6 +/- 1.9 vs. 3.0 +/- 1.3 pmol/L). There was a negative correlation between oxygen saturation and Et-1 levels in SCD patients (r = -0.71, P = 0.01). SCD subjects have more dilated and hypertrophied hearts corrected for body surface area than controls as evidenced by significant increases in left ventricular end diastolic dimension (31 +/- 0.8 vs. 24 +/- 0.9 mm/m2, P < 0.001), left ventricular end systolic dimension (20 +/- 0.9 vs. 16 +/- 0.8 mm/m2, P = 0.002), left ventricular posterior wall thickness (5.0 +/- 0.1 vs. 4.0 +/- 0.1 mm/m2, P < 0.001), and left ventricular mass (125 +/- 7.2 vs. 69 +/- 5.1 g/m2, P < 0.001). The index of left ventricular function, the shortening fraction, was not different between groups (34 +/- 1.2% in SCD vs. 35 +/- 1.5% in controls). The correlation between left ventricular mass and levels of Et-1 in SCD subjects was not significant (r = 0.47, P = 0.121).

Topics: Adolescent; Adult; Anemia, Sickle Cell; Body Surface Area; Echocardiography; Endothelin-1; Female; Humans; Hypertrophy, Left Ventricular; Male; Organ Size; Oxygen

We evaluated 30 consecutive patients and 48 age- and sex-matched controls to explore the possibility of a pathogenic contribution by plasma endothelin-1 in the cardiac expression of systemic sclerosis. Venous plasma endothelin-1 was measured by radio-immunoassay and left ventricular function by echocardiography. The patient group had elevated plasma endothelin-1 (2.6 +/- 0.2 vs. 1.8 +/- 0.1 pmol/1, P < 0.001), but endothelin-1 was not related to age, heart rate, blood pressure, total peripheral resistance, disease duration or systemic sclerosis score. Endothelin-1 was related to left ventricular hypertrophy in terms of septal thickness (r = 0.33, P < 0.01) and left ventricular mass index (r = 0.32, P < 0.01). Plasma endothelin-1 was further related to measures indicating reduced left ventricular filling; left atrial emptying index (r = -0.50, P < 0.0005), the first third filling fraction (r = -0.31, P < 0.05) and the time velocity integral of Doppler early/late filling velocity (r = -0.40, P < 0.001). Furthermore, circulating endothelin-1 was related to impaired left ventricular contractility as estimated by pre-ejection period/left ventricular ejection time (r = 0.32, P < 0.01) and end-systolic wall stress/volume index (r = -0.30, P < 0.05). We conclude that plasma endothelin-1 is elevated in relation to the degree of left ventricular hypertrophy, diastolic dysfunction and impaired contractility in systemic sclerosis. It may be of pathogenic importance to the cardiac involvement in systemic sclerosis which is not mediated via an increase in systemic blood pressure. It is not yet clear whether our findings are exclusive to systemic sclerosis patients or represent a generalized phenomenon in patients with impaired left ventricular function.

Topics: Adult; Aged; Atrial Natriuretic Factor; Cardiomyopathies; Case-Control Studies; Echocardiography; Endothelin-1; Female; Humans; Hypertrophy, Left Ventricular; Male; Middle Aged; Multivariate Analysis; Scleroderma, Systemic; Ventricular Dysfunction, Left

Osteopontin (OP) has been identified in cultured rat cardiac fibroblasts, where it contributes to angiotensin II (AII)-induced remodeling processes; in cultured cardiomyocytes; and in macrophages in cardiac tissues with inflammation. However, the presence of OP has not been reported in histological sections of myocardial tissue. In the present study, we investigated (1) the regulation of OP mRNA expression in cultured rat cardiomyocytes; (2) the localization of OP mRNA in neonatal and adult normal and hypertrophied rat hearts; and (3) the histology of OP expression in myocardial specimens from humans either with myocyte hypertrophy or with no pathological changes.. Cultured neonatal cardiomyocytes expressed OP mRNA and were immunoreactive for OP. Endothelin-1 (ET-1) and norepinephrine (NE) increased both OP and atrial natriuretic peptide (ANP) mRNA levels twofold to threefold (P<.01). OP mRNA was prominent in ventricular tissue from neonatal and adult rats with renovascular hypertension and aortic banding, whereas barely detectable levels were observed in normal adult cardiac tissue. ANP and OP mRNA levels in normal and hypertrophied ventricles correlated (r2=.87, P<.001). OP immunoreactivity and mRNA transcripts were predominantly found in cardiomyocytes not associated with inflammatory cells in sections from neonatal and adult hypertrophied hearts. No staining was detectable in normal adult hearts. Human myocardium with extensive fibrosis and cardiomyocyte hypertrophy obtained from explanted hearts with either idiopathic (n=5) or ischemic cardiomyopathy (n=7) demonstrated substantial myocyte immunoreactivity for both OP and ANP in right and left ventricles that was not associated with leukocyte infiltration. In situ hybridization identified cardiomyocytes as the major source of OP mRNA transcripts in these hearts. In contrast, OP immunoreactivity was not detectable in four of five endomyocardial biopsies with normal histology.. The present study provides the first evidence that cardiomyocytes are a prominent source of OP in vivo and suggests that induction of OP expression is strongly associated with ventricular hypertrophy.

Topics: Animals; Cells, Cultured; Endothelin-1; Gene Expression Regulation; Humans; Hypertrophy, Left Ventricular; Male; Middle Aged; Myocardium; Norepinephrine; Osteopontin; Rats; Rats, Sprague-Dawley; RNA, Messenger; Sialoglycoproteins

Left ventricular dilatation after myocardial infarction is associated with impaired ventricular function and heart failure and has important implications for survival. The purpose of this study was to investigate the role of endothelin-1 (ET-1) in ventricular dilatation and the effects of chronic endothelin receptor blockade by a mixed ET(A) and ET(B) receptor blocker (bosentan) on the circulating and cardiac endothelin systems.. Three hours after coronary ligation or sham operation, bosentan (100 mg x kg body wt(-1) x d(-1)) or placebo was given by gavage. Seven days and 8 weeks after surgery, hemodynamic and left ventricular volume studies were performed. Acute bosentan treatment (7 days) had no effects on hemodynamic parameters and early left ventricular dilatation. In the rats with large infarcts, chronic bosentan treatment (8 weeks) versus placebo reduced left ventricular systolic pressure (116+/-2 versus 125+/-3 mm Hg, P<.05) and arterial pressure (93+/-2 versus 103+/-3 mm Hg, P<.05), improved stroke volume index (0.69+/-0.06 versus 0.52+/-0.04 mL/kg, P<.05), and prevented in part the rightward shift of the pressure-volume curve. Chronic bosentan treatment also decreased ET-1 levels (390+/-33 versus 475+/-22 pg/g tissue, P<.05) and density of ET-1 receptors (262+/-24 versus 346+/-31 fmol/mg protein, P<.05) in left ventricular myocardium.. In the present study, a mixed ET(A) and ET(B) receptor antagonist (bosentan) partially prevented left ventricular dilatation and improved hemodynamics, suggesting that endothelin plays a role in left ventricular remodeling after myocardial infarction. Supporting this hypothesis, we show inhibitory effects of bosentan on the peripheral and myocardial endothelin system.

Topics: Animals; Antihypertensive Agents; Bosentan; Dose-Response Relationship, Drug; Endothelin-1; Female; Heart Ventricles; Hemodynamics; Hypertrophy, Left Ventricular; Myocardial Infarction; Rats; Rats, Wistar; Receptors, Endothelin; Sulfonamides; Time Factors

The phenotypic expression of left ventricular hypertrophy (LVH) in patients with hypertrophic cardiomyopathy (HCM) is variable. This phenotypic variability is not completely explained by the responsible mutations or other known factors. Recent data denote a role for the modifier genes and environmental factors. We studied the role of 3 potential modifier genes, i.e., angiotensinogen (AGT), angiotensin II receptor 1a (AT1a), and endothelin-1 (END1) on the phenotypic expression of LVH in patients with hypertrophic cardiomyopathy (HCM).. The study population was comprised of 108 genetically independent patients with HCM. Left ventricular mass index (LVMI) and LVH score were determined per published protocols. The genotypes of AGT (M235T, T174M, and G-6A), AT1a, and END1 were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or mutation-specific PCR (MS-PCR).. Male patients had higher mean LVMI and LVH score than female patients (146.0 +/- 33.5 vs 129.4 +/- 33.6, p = 0.01 and 6.0 vs 5.0, p = 0.010, respectively). Gender accounted for 4.8% and 5.4% of the variability of LVMI and LVH score, respectively. The END1 genotypes also had a significant influence on LVH scores accounting for 2.9% of their variability (p = 0.042). The median LVH score was greater in patients with the AA and AG genotypes, as compared to patients with the GG genotype (7.0 vs 5.0, p = 0.034). Neither the AGT nor the AT1 genotypes had a significant influence on the expression of LVH. In multivariate regression analysis, END1 and gender accounted for 7.3% of the variability of the LVH score (p = 0.007).. Our results show that gender and the END1 gene modify the phenotypic expression of hypertrophy in patients with HCM.

Topics: Adult; Angiotensinogen; Cardiomyopathy, Hypertrophic; DNA Primers; Endothelin-1; Female; Gene Expression; Genotype; Humans; Hypertrophy, Left Ventricular; Male; Middle Aged; Phenotype; Polymerase Chain Reaction; Polymorphism, Genetic; Receptors, Angiotensin; Sex Characteristics

We have recently shown that angiotensin II-induced hypertrophy of cultured rat cardiomyocytes was partially blocked by an endothelin (ET) receptor antagonist (BQ123) selective for the ETA subtype, suggesting the possible involvement of endogenous ET-1 in the mechanism of cardiac hypertrophy in vitro. In the present study, we studied the in vivo blockade effects of BQ123 on cardiac hypertrophy provoked by left ventricular overload with aortic banding in adult rats.. Forty rats were divided into four groups: (1) sham-operated rats without BQ123 administration, (2) rats with aortic banding without BQ123 administration, (3) sham-operated rats with BQ123 administration, and (4) rats with aortic banding with BQ123 administration. BQ123 (250 micrograms/h) was administered continuously by an osmotic pump starting 24 hours before operation. BQ123 blocked increases in the ratio of left ventricular weight to body weight and in the diameter of cardiomyocytes provoked by aortic banding at 1 week, but those blockade actions were no longer observed at 2 weeks. Skeletal alpha-actin and atrial natriuretic peptide (ANP) mRNA in the left ventricle, transcriptional markers for cardiac hypertrophy, significantly increased in the rats with aortic banding at 1 week and 2 weeks. In the rats with BQ123 administration, despite the hemodynamic overload, skeletal alpha-actin and ANP mRNA in the left ventricle remained at the control levels at 1 week; however, those blockade actions were abolished at 2 weeks. Plasma ET-1 levels increased after aortic banding, peaking at 24 hours, then returned to the basal level at 4 days. Prepro-ET-1 mRNA levels in the left ventricle also increased 24 hours after aortic banding, then declined to the basal level at 4 days.. These data suggest that endogenous ET-1 synthesized in the cardiovascular system plays a role in the mechanism of cardiac hypertrophy during the early phase of pressure overload in vivo.

Topics: Actins; Animals; Atrial Natriuretic Factor; Endothelin Receptor Antagonists; Endothelin-1; Endothelins; Gene Expression; Hypertrophy, Left Ventricular; Male; Peptides, Cyclic; Protein Precursors; Rats; Rats, Wistar; RNA, Messenger