endothelin-1 and Cardiac-Output--Low

Chemotherapy is an established approach for several malignancies, but its utility may be hampered by induced cardiac toxicity possibly leading to heart failure, with a negative impact on the patient's quality of life and ultimately survival. Prospective left ventricular systolic function monitoring has demonstrated that cardiotoxicity could be subclinically present for many months or years before its overt manifestation. Although considered irreversible, some reports suggested recovery or delayed progression of cardiac dysfunction by preventive cardioactive therapies. Thus, the identification of earlier instrumental or biochemical markers of cardiac injury able to predict heart failure remains a major task. Diastolic indexes as a primary expression of hemodynamic dysfunction after cardiac damage, analyzed by means of conventional or newer Doppler technologies (tissue Doppler, color M-mode, etc.) are discussed. Moreover, brain natriuretic peptides, troponins and endothelin-1, as possible sensitive/specific markers/predictors of subclinical cardiotoxicity are reviewed in order to update and possibly improve the strategy for the detection and clinical management of chemotherapy-related cardiotoxic effects.

Topics: Antineoplastic Combined Chemotherapy Protocols; Biomarkers; Cardiac Output, Low; Endothelin-1; Female; Heart Failure; Humans; Male; Natriuretic Peptide, Brain; Neoplasms; Predictive Value of Tests; Primary Prevention; Prognosis; Quality of Life; Sensitivity and Specificity; Severity of Illness Index; Troponin; Ventricular Dysfunction, Left

Sympatho-excitation is a hallmark of the chronic heart failure (CHF) state. It has long been assumed that this sympatho-excitation is mediated by a reduction in sensory input from cardiopulmonary and arterial baroreceptors. However, recent data suggest that these reflexes may only be important in the initiation of the sympatho-excitatory state and may not be necessary for the sustained increase in sympathetic nerve activity (SNA) in CHF. Two humoral factors that can influence SNA are nitric oxide (NO) and angiotensin II (AngII). Animals with CHF exhibit a downregulation in central gene expression for the neuronal isoform of nitric oxide synthase (nNOS). In addition, blockade of AngII receptors in combination with NO donation reduces SNA in animals with CHF, while NO donation alone has no effect on SNA. Chronic exercise training (EX) reduces both plasma AngII and SNA in rabbits with CHF while improving baroreflex function. Blockade of AT1 receptors enhances baroreflex function in non-EX CHF rabbits, but has little effect in EX CHF rabbits. These data suggest that the sympatho-excitatory state that is typical of CHF is, in part, due to changes in AngII and NO. Depressed baroreflex function and the elevated SNA can be improved by EX in animals with CHF.

Topics: Angiotensin II; Animals; Cardiac Output, Low; Chronic Disease; Endothelin-1; Nitric Oxide; Physical Conditioning, Animal; Sympathetic Nervous System

There is now considerable evidence to suggest that neurohormonal and immune mechanisms may play a central role in the pathogenesis of chronic heart failure (CHF), which is likely to have important implications for the management of this condition. It has been proposed that CHF is a state of immune activation with inflammatory cytokines contributing to both the central and the peripheral manifestations of this syndrome. The immune system is the body's natural defence mechanism against infection and other stresses, which has several different components that interact with each other in a complex manner. The main components which are thought to be relevant to the pathogenesis of CHF are: cytokines, adhesion molecules, autoantibodies, nitric oxide, and endothelin-1, and this review will concentrate on these factors. This article will also discuss the potential role of anti-cytokine therapies in the treatment of CHF.

Topics: Autoantibodies; Cardiac Output, Low; Cell Adhesion Molecules; Chronic Disease; Cytokines; Endothelin-1; Humans; Inflammation Mediators; Nitric Oxide; Oxidative Stress; Tumor Necrosis Factor-alpha

Mechanical stretch induced by high blood pressure is an initial factor leading to cardiac hypertrophy. In an in vivo study, an angiotensin II (AngII) type 1 receptor antagonist TCV116 reduced left ventricular (LV) weight, LV wall thickness, transverse myocyte diameter, relative amount of V3 myosin heavy chain, and interstitial fibrosis, while treatment with hydralazine did not. In an in vitro study using cultured cardiomyocytes, mechanical stretch activated second messengers such as mitogen-activated protein (MAP) kinase, followed by increased protein synthesis. Additionally, in the stretch-conditioned medium AngII and endothelin-1 concentrations were increased. Furthermore, the Na+/H+ exchanger activated by mechanical stretch modulated the hypertrophic responses of cardiomyocytes. The pathways leading to MAP kinase activation differed between cell types. In cardiac fibroblasts AngII activated MAP kinase via G beta gamma subunit of Gi, Src, Shc, Grb2, and Ras, whereas Gq and protein kinase C were critical in cardiomyocytes.

Topics: Angiotensin II; Animals; Cardiac Output, Low; Cardiomegaly; Endothelin-1; Hypertension; Myocardium; Renin-Angiotensin System; Signal Transduction; Sodium-Hydrogen Exchangers; Stress, Mechanical

Endothelin-1, discovered in 1988, is a 21-amino-acid peptide and currently the most potent vasoconstrictor and pressor substance known. Generated by vascular endothelial cells in response to a variety of chemical and mechanical signals, endothelin-1 is known to potentiate the actions of other vasoconstrictor substances and act as a comitogen in addition to directly causing vasoconstriction. There is evidence that endothelin-1 may contribute to the pathophysiology of conditions associated with sustained vasoconstriction, such as hypertension and heart failure, vasospastic conditions, such as subarachnoid hemorrhage, and atherogenesis. Studies using endothelin receptor antagonists show that endothelin-1 plays an important role in the maintenance of vascular tone and blood pressure in healthy humans, predominantly via an effect on the vascular smooth muscle ETA receptors. The endothelin receptor antagonist bosentan also effectively lowers blood pressure in hypertensive subjects and produces sustained and favorable effects on systemic and pulmonary hemodynamics in patients with chronic heart failure. A good side-effect profile, together with a potential for inhibition of atherogenesis, makes the endothelin receptor antagonists a potentially interesting class of novel agents for the treatment of cardiovascular disease.

Topics: Amino Acid Sequence; Animals; Cardiac Output, Low; Cardiovascular Physiological Phenomena; Cardiovascular System; Chronic Disease; Endothelin-1; Endothelins; Humans; Hypertension

The endothelins are a family of three structurally related peptides. Endothelin-1 (ET-1) is formed from the big endothelin by the action of the endothelin converting enzyme. It acts on two types of receptor, ETA and ETB. ET-1 is a powerful vasoconstrictor but also has a number of other effects: positive inotropism and stimulation of cell growth, for example. Endothelin is found in the general circulation but its role is mainly local in maintaining vascular tone. The endothelin system is activated in cardiac failure and increased concentrations of plasma endothelin increased, ET-1 converting enzyme and increased density of endothelin receptors are observed. The action of the endothelin system and its relationships with other neuro-hormonal systems activated in cardiac failure are not fully understood but research is under way which should clarify these mechanisms in the next few years. In view of the properties of endothelin, inhibition of its action might be particularly useful in patients with cardiac failure. Its action can be blocked either by preventing its synthesis by inhibiting the endothelin converting enzyme or by blocking the endothelin receptor. Endothelin receptor blockade is associated with beneficial haemodynamic changes, an action on ventricular remodelling and possibly an improved prognosis. Many substances, either selective for ETA receptors or mixed ETA and ETB receptor blockers, are under development. The benefits of these products will require confirmation by large scale clinical trials.

Topics: Cardiac Output, Low; Chronic Disease; Endothelin Receptor Antagonists; Endothelin-1; Endothelins; Glycopeptides; Humans; Metalloendopeptidases

To investigate the potential differential effects of selective endothelin (ET) A and dual ET-A/B receptor blockade in patients with chronic heart failure.. Nine patients with chronic heart failure (New York Heart Association class II-III) each received intravenous infusions of BQ-123 alone (selective ET-A blockade) and combined BQ-123 and BQ-788 (dual ET-A/B blockade) in a randomised, placebo controlled, three way crossover study.. Selective ET-A blockade increased cardiac output (maximum mean (SEM) 33 (12)%, p < 0.001) and reduced mean arterial pressure (maximum -13 (4)%, p < 0.001) and systemic vascular resistance (maximum -26 (8)%, p < 0.001), without changing heart rate (p = 0.38). Dual ET-A/B blockade significantly reduced the changes in all these haemodynamic variables compared with selective ET-A blockade (p < 0.05). Selective ET-A blockade reduced pulmonary artery pressure (maximum 25 (7)%, p = 0.01) and pulmonary vascular resistance (maximum 72 (39)%, p < 0.001). However, there was no difference between these effects and those seen with dual ET-A/B blockade. Unlike selective ET-A blockade, dual ET-A/B blockade increased plasma ET-1 concentrations (by 47 (4)% with low dose and 61 (8)% with high dose, both p < 0.05).. While there appeared to be similar reductions in pulmonary pressures with selective ET-A and dual ET-A/B blockade, selective ET-A blockade caused greater systemic vasodilatation and did not affect ET-1 clearance. In conclusion, there are significant haemodynamic differences between selective ET-A and dual ET-A/B blockade, which may determine responses in individual patients.

Topics: Adult; Aged; Antihypertensive Agents; Cardiac Output; Cardiac Output, Low; Cross-Over Studies; Drug Therapy, Combination; Endothelin A Receptor Antagonists; Endothelin Receptor Antagonists; Endothelin-1; Female; Heart Rate; Hemodynamics; Humans; Infusions, Intravenous; Male; Middle Aged; Oligopeptides; Peptides, Cyclic; Piperidines; Treatment Outcome; Ventricular Function

Blockade of AngII (angiotensin II) and ET (endothelin)-1, established and potential therapeutic strategies respectively, for heart failure, may have an adverse effect on the cardiac secretion of the natriuretic peptides, hormones with actions beneficial in this disease. The present study investigates the roles of AngII and ET-1 in regulating the stretch-induced release of the natriuretic peptides during the development of heart failure. On seven separate days, eight sheep underwent incremental left ventricular pacing (155, 190 and 225 beats/min for 90 min each) with concurrent infusions of a vehicle control, AngII, ET-1, AngII+ET-1, losartan [AT1 (AngII type 1) receptor antagonist], bosentan (ET(A)/ET(B) receptor antagonist) or losartan+bosentan. Pacing-induced rises in LAP (left atrial pressure) were amplified by the simultaneous administration of separate AngII and ET-1, and attenuated following blockade of the peptides, with maximum effects observed during combined treatments. Although these changes in atrial pressure were paralleled by concomitant alterations in circulating levels of both ANP (atrial natriuretic peptide) and BNP (brain natriuretic peptide), the plasma natriuretic peptide/atrial pressure relationship tended to be augmented by AngII and ET-1 and diminished by their blockade. A significant difference was demonstrated between the enhanced plasma BNP response to increasing LAP during combined AngII+ET-1 administration and decreased response during losartan+bosentan treatment ( P <0.05). A similar, but non-significant, trend was evident for ANP. The present study indicates dual AngII/ET-1 blockade diminishes BNP (and to a lesser extent ANP) secretion in developing heart failure, suggesting that augmentation of the natriuretic peptide system during the combination of these therapies may be of benefit.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Animals; Anti-Arrhythmia Agents; Antihypertensive Agents; Atrial Natriuretic Factor; Blood Pressure; Bosentan; Cardiac Output; Cardiac Output, Low; Cardiac Pacing, Artificial; Cyclic GMP; Endothelin Receptor Antagonists; Endothelin-1; Female; Infusions, Parenteral; Losartan; Natriuretic Peptide, Brain; Renin; Sheep; Sulfonamides

Inhaled nitric oxide (iNO) therapy is an effective treatment of pulmonary hypertension following left ventricular assist device (LVAD) implantation. As iNO may also modulate circulating endothelin-1 (ET-1) and big endothelin following LVAD implantation, we investigated the effects of iNO on ET-1 and big endothelin plasma concentration gradients. In order to assist weaning from cardiopulmonary bypass, iNO was administered to 15 consecutive patients with secondary pulmonary hypertension following implantation of a LVAD. Central venous, pulmonary arterial and arterial ET-1 and big endothelin plasma levels were measured preoperatively, on cardiopulmonary bypass prior to iNO administration, 12, 24 and 48 hours postoperatively, and 72 hours after weaning from iNO. The ET-1 gradients between central venous and pulmonary arterial plasma levels decreased significantly with time, and there was a trend for lower arterial-pulmonary arterial plasma concentration gradients. Big endothelin plasma concentration gradients were not altered significantly. The decrease in ET-1 plasma concentration gradients during and after iNO administration may reflect a restoration of the physiologic balance between the different vascular beds. This provides further evidence that intermittent iNO therapy may modulate ET-1 after LVAD implantation.

Topics: Administration, Inhalation; Antihypertensive Agents; Blood Pressure; Cardiac Output, Low; Cardiopulmonary Bypass; Central Venous Pressure; Down-Regulation; Endothelin-1; Female; Heart Failure; Heart-Assist Devices; Humans; Hypertension, Pulmonary; Intraoperative Care; Male; Middle Aged; Nitric Oxide; Time Factors; Treatment Outcome; Ventricular Dysfunction, Right

Elevated plasma endothelin-1 (ET-1) levels in patients with chronic heart failure correlate with pulmonary artery pressures and pulmonary vascular resistance. ET(A) receptors on vascular smooth muscle cells mediate pulmonary vascular contraction and hypertrophy. We determined the acute hemodynamic effects of sitaxsentan, a selective ET(A) receptor antagonist, in patients with chronic stable heart failure receiving conventional therapy.. This multicenter, double-blind, placebo-controlled trial enrolled 48 patients with chronic New York Heart Association functional class III or IV heart failure (mean left ventricular ejection fraction 21+/-1%) treated with ACE inhibitors and diuretics. Patients with a baseline pulmonary capillary wedge pressure >/=15 mm Hg and a cardiac index

Topics: Cardiac Output, Low; Chronic Disease; Double-Blind Method; Endothelin Receptor Antagonists; Endothelin-1; Female; Hemodynamics; Humans; Male; Middle Aged; Norepinephrine; Pulmonary Circulation; Receptor, Endothelin A; Time Factors; Tumor Necrosis Factor-alpha; Vasodilation; Vasodilator Agents

The role of biomarkers in asymptomatic diastolic dysfunction (DD) has not been investigated so far. The aim of the study was to evaluate the clinical associations and the diagnostic property of different biomarkers in patients with asymptomatic DD.. Within a population based observational study, healthy participants (50-85 years) with an LVEF ≥ 50 % and no cardiovascular risk factor were prospectively identified. Patients were classified as having either DD (grade ≥ 1, n = 103) or no DD (CON: n = 85). All patients underwent physical examination including medical history, six-minute-walk-testing, QoL (SF-36), comprehensive echocardiography and blood sampling to measure routine values and specified biomarkers (NTproBNP, MRproANP, GDF-15, MRproADM, CTproET1, CTproAVP).. In the DD-group plasma concentration of GDF-15 (p = 0,002), MRproADM (p < 0,001), and CTproAVP (p = 0,003) were significantly higher than in the CON-group. In contrast, NTproBNP (p = 0,390), MRproANP (p = 287), and CTproET1 (p = 0,393) did not differ. GDF-15, MRproADM and CTproAVP were significantly associated with the presence of DD. However, the significance of the seen associations was lost after multiple adjustments. NTproBNP, MRproANP, and MRproADM were significantly related to E / e' as a continuous measure of diastolic function. The significance of the seen associations was lost after multiple adjustments. In ROC analyses, none of the investigated biomarkers was able to relevantly improve the diagnosis of DD.. In patients with asymptomatic DD plasma concentrations of GDF-15, MRproADM and CT-proAVP were significantly higher when compared with controls. In contrast, NTproBNP, MRproANP and CTproET1 did not differ. After adjustment for age, sex, BMI and renal function, no significant association between DD or E / e' and different biomarkers could be observed. Furthermore, none of the investigated biomarkers was able to substantially improve the diagnosis of DD.

Topics: Adrenomedullin; Aged; Aged, 80 and over; Biomarkers; Cardiac Output, Low; Endothelin-1; Female; Glycopeptides; Growth Differentiation Factor 15; Heart Failure, Diastolic; Humans; Male; Middle Aged; Peptide Fragments; Predictive Value of Tests; Protein Precursors; Reference Values; Risk Factors

The mechanisms underlying the reactive component of pulmonary hypertension (PH) in heart failure (HF) are unclear. We examined whether resting systemic oxygen levels are related to pulmonary hemodynamics in HF.. Thirty-nine HF patients underwent right heart catheterization. Subsequently, patients were classified as having: 1) no PH (n = 12); 2) passive PH (n = 10); or 3) reactive PH (n = 17). Blood was drawn from the radial and pulmonary arteries for the determination of PaO(2), SaO(2), PvO(2), SvO(2), and vasoactive neurohormones. PaO(2) and PvO(2) were lower in reactive PH versus no PH and passive PH patients (65.3 ± 8.6 vs 78.3 ± 11.4 mm Hg and 74.5 ± 14.0 mm Hg; 29.2 ± 4.1 vs 36.2 ± 2.8 mm Hg and 33.4 ± 2.3 mm Hg; P < .05). SaO(2) and SvO(2) were lower in reactive PH versus no PH patients (93 ± 3% vs 96 ± 3%; 51 ± 11% vs 68 ± 4%; P < .05), but not different versus passive PH patients. The transpulmonary pressure gradient (TPG) was inversely related to PaO(2), PvO(2), SaO(2), and SvO(2) in the reactive PH patients only (r ≤ -0.557; P < .05). Similarly, plasma endothelin-1 correlated with PaO(2), PvO(2), SvO(2) (r ≤ -0.495), and TPG (r = 0.662; P < .05) in reactive PH patients only.. Systemic hypoxia may play a role in the reactive component of PH in HF, potentially via a hypoxia-induced increase in endothelial release of the vasoconstrictor endothelin-1.

Topics: Adult; Aged; Blood Gas Analysis; Cardiac Catheterization; Cardiac Output, Low; Cohort Studies; Disease Progression; Endothelin-1; Female; Heart Failure; Hemodynamics; Humans; Hypertension, Pulmonary; Hypoxia; Male; Middle Aged; Multivariate Analysis; Neurotransmitter Agents; Oxygen; Prognosis; Prospective Studies; Regression Analysis; Risk Assessment; Severity of Illness Index; Survival Rate; Vascular Resistance

To investigate endothelin-1 (ET-1)-dependent hepatic and mesenteric vasoconstriction, and oxygen and lactate fluxes in an acute, fixed low cardiac output (CO) state.. Sixteen anesthetized, mechanically ventilated pigs were studied. Cardiac tamponade was established to reduce portal venous blood flow (Q(PV)) to 2/3 of the baseline value. CO, hepatic artery blood flow (Q(HA)), Q(PV), hepatic laser-Doppler flow (LDF), hepatic venous and portal pressure, and hepatic and mesenteric oxygen and lactate fluxes were measured. Hepatic arterial (R(HA)), portal (R(HP)) and mesenteric (R(mes)) vascular resistances were calculated. The combined ET(A)-ET(B) receptor antagonist tezosentan (RO 61-0612) or normal saline vehicle was infused in the low CO state. Measurements were made at baseline, after 30, 60, 90 min of tamponade, and 30, 60, 90 min following the infusion of tesozentan at 1 mg/kg/h.. Tamponade decreased CO, Q(PV), Q(HA), LDF, hepatic and mesenteric oxygen delivery, while hepatic and mesenteric oxygen extraction and lactate release increased. R(HA), R(HP) and R(mes) all increased. Ninety minutes after tesozentan, Q(PV), LDF and hepatic and mesenteric oxygen delivery and extraction increased approaching baseline values, but no effect was seen on CO or Q(HA). Hepatic and mesenteric handling of lactate converted to extraction. R(HA), R(HP) and R(mes) returned to baseline values. No changes were observed in these variables among control animals not receiving tesozentan.. In a porcine model of acute splanchnic hypoperfusion, unselective ET-1 blockade restored hepatomesenteric perfusion and reversed lactate metabolism. These observations might be relevant when considering liver protection in low CO states.

Topics: Animals; Carbon Dioxide; Cardiac Output, Low; Cardiac Tamponade; Drug Evaluation, Preclinical; Endothelin Receptor Antagonists; Endothelin-1; Female; Lactates; Liver Circulation; Male; Models, Animal; Oxygen; Oxygen Consumption; Pyridines; Splanchnic Circulation; Sus scrofa; Tetrazoles; Vascular Resistance; Vasoconstriction

Urocortin 1 (Ucn1) may be involved in the pathophysiology of heart failure (HF), but the impact of Ucn1 administration on progression of the disease is unknown. The aim of this study was to investigate the effects of Ucn1 in sheep from the onset of cardiac overload and during the subsequent development of HF. Eight sheep underwent two 4-day periods of HF induction by rapid left ventricular pacing (225 beats/min) in conjunction with continuous infusions of Ucn1 (0.1 microg.kg(-1).h(-1) iv) and a vehicle control (0.9% saline). Compared with control, Ucn1 attenuated the pacing-induced decline in cardiac output (2.43 +/- 0.46 vs. 3.70 +/- 0.89 l/min on day 4, P < 0.01) and increases in left atrial pressure (24.9 +/- 1.0 vs. 11.9 +/- 1.1 mmHg, P < 0.001) and peripheral resistance (38.7 +/- 9.4 vs. 25.2 +/- 6.1 mmHg.l(-1).min, P < 0.001). Ucn1 wholly prevented increases in plasma renin activity (4.02 +/- 1.17 vs. 0.87 +/- 0.1 nmol.l(-1).h(-1), P < 0.001), aldosterone (1,313 +/- 324 vs. 413 +/- 174 pmol/l, P < 0.001), endothelin-1 (3.8 +/- 0.5 vs. 2.0 +/- 0.1 pmol/l, P < 0.001), and vasopressin (10.8 +/- 4.1 vs. 1.8 +/- 0.2 pmol/l, P < 0.05) during pacing alone and blunted the progressive increases in plasma epinephrine (2,132 +/- 697 vs. 1,250 +/- 264 pmol/l, P < 0.05), norepinephrine (3.61 +/- 0.73 vs. 2.07 +/- 0.52 nmol/l, P < 0.05), and atrial (P < 0.05) and brain (P < 0.01) natriuretic peptide levels. Ucn1 administration also maintained urine sodium excretion (0.75 +/- 0.34 vs. 1.59 +/- 0.50 mmol/h on day 4, P < 0.05) and suppressed pacing-induced declines in creatinine clearance (P < 0.05). These findings indicate that Ucn1 treatment from the onset of cardiac overload has the ability to repress the ensuing hemodynamic and renal deterioration and concomitant adverse neurohumoral activation, thereby delaying the development of overt HF. These data strongly support a use for Ucn1 as a therapeutic option early in the course of the disease.

Topics: Aldosterone; Animals; Blood Pressure; Cardiac Output, Low; Corticotropin-Releasing Hormone; Endothelin-1; Epinephrine; Female; Heart Conduction System; Infusions, Intra-Arterial; Kidney; Norepinephrine; Renin; Sheep; Urocortins; Vascular Resistance; Vasopressins; Ventricular Function, Left

It has been reported that high intramyocardial peroxisome proliferator-activated receptor alpha (PPARalpha) stimulation or overexpression altered cardiac contractile function in mouse models of cardiac hypertrophy and heart failure. Nevertheless, it has never been demonstrated that clinically relevant doses of drugs stimulating PPARalpha activity such as fenofibrate increase the risk to develop heart failure in humans. To determine if fenofibrate accelerates the development of heart failure in large mammals, we have tested its effects on the progression of left ventricular dysfunction in pacing-induced heart failure in pigs. Fenofibrate treatment blunted reduction in left ventricular ejection fraction, reduced cardiac hypertrophy, and attenuated clinical signs of heart failure. Fenofibrate impeded the increase in atrial natriuretic peptide, brain natriuretic peptide, and endothelin-1 plasma levels. The expression of PPARalpha, fatty acyl-CoA-oxidase, and carnitine palmitoyltransferase-Ibeta was reduced at mRNA levels in the left ventricle from untreated heart failure pigs but maintained near normal values with fenofibrate. Fenofibrate prevented heart failure-induced overexpression of TNFalpha mRNA and enhanced catalase activity in left ventricle compared to placebo. These data suggest that a clinically relevant dose of fenofibrate does not accelerate but slows down heart failure development in the model of pacing-induced heart failure in large mammals.

Topics: Acyl-CoA Oxidase; Animals; Atrial Natriuretic Factor; Biomarkers; Cardiac Output, Low; Cardiomyopathies; Carnitine O-Palmitoyltransferase; Endothelin-1; Female; Fenofibrate; Myocardium; Natriuretic Peptide, Brain; Oxidative Stress; PPAR alpha; RNA, Messenger; Swine; Tachycardia; Thiobarbituric Acid Reactive Substances; Ventricular Dysfunction, Left

We hypothesized that recombinant B-type natriuretic peptide (BNP) (nesiritide) could improve urine output and neurohormonal markers of heart failure without worsening renal function in pediatric patients.. We analyzed our experience involving 140 nesiritide infusions in 63 consecutive children. Serum levels of BNP and electrolytes were measured before and after therapy. Dosing was begun at 0.01 mcg.kg.min without a bolus and titrated to a maximum of 0.03 mcg.kg.min, in 0.005-mcg.kg.min increments. Blood pressure, heart rate, and heart rhythm were monitored. In a substudy, 20 patients with decompensated cardiomyopathy-related heart failure received 72 hours of nesiritide with prospective assessment of aldosterone, norepinephrine, plasma renin, and endothelin-1 levels before and after therapy. The heart rate decreased significantly (P = .001). Urine output increased significantly on Days 1 and 3 (P < or = .001 and .004, respectively). The mean serum creatinine level decreased from 1.135 to 1.007 mg/dL (P < or = .001). In the substudy, aldosterone levels decreased from 37.5 +/- 57.1 to 20.5 +/- 41.9 ng/dL (P = .005). Plasma renin, norepinephrine, and endothelin-1 levels decreased nonsignificantly. Two infusions were discontinued because of hypotension.. Nesiritide safely treated decompensated heart failure in children. Increased urine output reflected improving renal function. Improved neurohormonal markers were seen after 72 hours of therapy, and complications were uncommon.

Topics: Adolescent; Adult; Aldosterone; Biomarkers; Cardiac Output, Low; Cardiomyopathies; Child; Child, Preschool; Creatinine; Diuresis; Endothelin-1; Female; Heart Failure; Heart Rate; Humans; Infant; Infant, Newborn; Kidney; Male; Natriuretic Agents; Natriuretic Peptide, Brain; Norepinephrine; Prospective Studies; Renin; Treatment Outcome

Endothelin is elevated in heart failure and contributes to neurohormonal activation, hemodynamic deterioration, and cardiovascular remodeling. Here, we examined its prognostic value in a large population of patients with chronic heart failure.. Big endothelin-1 (Big ET-1) and 4 other neurohormones were measured at study entry in 2359 patients enrolled in the Valsartan Heart Failure Trial (Val-HeFT) and their concentrations related to outcome over a median follow-up of 23 months. Baseline concentration of Big ET-1 (median 0.80 pmol/L) was proportional to severity of disease (New York Heart Association class, left ventricular structure and function). High circulating concentrations of brain natriuretic peptide (BNP), creatinine and bilirubin, advanced New York Heart Association class, elevated body mass index, and the presence of atrial fibrillation were independently associated to higher concentrations of Big ET-1. Big ET-1 (ranking second just behind BNP among neurohormonal factors) was an independent predictor of outcome defined as all-cause mortality (hazard ratio 1.49, 95% CI 1.20-1.84, P = .0003) or the combined endpoint of mortality and morbidity (hazard ratio 1.43, 95% CI 1.20-1.69, P < .0001) and provided incremental prognostic value compared with BNP.. In a large population of patients with symptomatic heart failure, the circulating concentration of Big ET-1, a precursor of the paracrine and bioactive peptide ET-1, was an independent marker of mortality and morbidity. In this setting, BNP remained the strongest neurohormonal prognostic factor.

Topics: Aged; Cardiac Output, Low; Chronic Disease; Endothelin-1; Female; Humans; Male; Middle Aged; Multicenter Studies as Topic; Natriuretic Peptide, Brain; Osmolar Concentration; Prognosis; Proportional Hazards Models; Randomized Controlled Trials as Topic; Severity of Illness Index

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

The pregnancy hormone relaxin has been raised as a new compensatory mediator of cardiac origin in heart failure (HF). We set out to assess the role of relaxin in pressure overload-induced human HF.. We studied 129 adult patients undergoing cardiac catheterization for isolated aortic valve stenosis (AS). Blood was sampled from the aortic root and, in a subset of 49 patients, from the coronary sinus for the determination of plasma relaxin by enzyme immunoassay. HF was diagnosed when the patient had dyspnea or fatigue on ordinary effort in association with pulmonary wedge pressure >14 mm Hg at catheterization.. Forty-one patients had HF, which was systolic (ejection fraction <50%) in 16 patients and diastolic in 25 patients. The median plasma relaxin was 32 pg/ml (<12-297 pg/ml) in 88 AS patients without HF, 28 pg/ml (<12-825 pg/ml) in the 41 AS patients with HF, and 42 pg/ml (range, <12-100 pg/ml) in 11 control patients free of heart disease (p=0.82). Plasma relaxin did not correlate with any measurement of cardiac structure or function. The concentration gradients of relaxin from the aortic root to the coronary sinus indicated relaxin extraction by the heart in the control patients (median change, -5 pg/ml, p=0.038) vs. relaxin production in patients with systolic HF (median change, +6 pg/ml, p=0.028) (p=0.002 between groups).. Although the heart may release relaxin into the circulation in certain forms of HF, this does not translate into elevated systemic concentrations. Relaxin is not a major player in human HF.

Topics: Adult; Aged; Aged, 80 and over; Aortic Valve Stenosis; Cardiac Catheterization; Cardiac Output, Low; Case-Control Studies; Endothelin-1; Female; Humans; Male; Middle Aged; Natriuretic Peptide, Brain; Nerve Tissue Proteins; Peptide Fragments; Relaxin

CGS 26303 is a vasopeptidase inhibitor that simultaneously inhibits endothelin-converting enzyme (ECE) and neutral endopeptidase (NEP). We compared the effects of chronic treatment with CGS 26303 to the selective inhibition of angiotensin-converting enzyme (ACE) and NEP during the transition from left ventricular hypertrophy (LVH) to congestive heart failure (CHF) in hypertensive rats. LV geometry and function were assessed in Dahl salt-sensitive rats placed on a high-salt diet from age 6 weeks (hypertensive rats) and in control rats fed a low-salt diet. The hypertensive rats were randomized into groups that received no treatment or were treated with an ACE inhibitor (temocapril), an ECE/NEP inhibitor (CGS 26303), or a NEP inhibitor (CGS 24592) from the LVH stage (11 weeks) to the CHF stage (17 weeks). All treatments decreased the systolic blood pressure equally and significantly improved LV fractional shortening. Both temocapril and CGS 26303 ameliorated LV perivascular fibrosis, reduced mRNA levels of types I and III collagen, and decreased the heart weight/body weight ratio. CHF rats had increased plasma ET-1 levels compared with control rats. Only CGS 26303 reduced ET-1 to normal levels. ET-1 levels were found to correlate with heart/body weight, right ventricle/body weight and perivascular fibrosis ratios. During the transition to CHF, CGS 26303 produces effects that are comparable to temocapril and superior to CGS 24592. The beneficial effects of CGS 26303 are likely caused in part by the greater reduction of plasma ET-1. Dual ECE/NEP inhibitor may provide a new strategy for the treatment of human heart failure.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Aspartic Acid Endopeptidases; Atrial Natriuretic Factor; Cardiac Output, Low; Cardiomegaly; Collagen; Echocardiography; Endothelin-1; Endothelin-Converting Enzymes; Enzyme Inhibitors; Fibrosis; Heart; Male; Metalloendopeptidases; Myocardium; Neprilysin; Neurotransmitter Agents; Organophosphonates; Phenylalanine; Rats; Rats, Inbred Dahl; RNA, Messenger; Tetrazoles; Thiazepines

The first objective of the study was to compare the levels of big endothelin and endothelin-1 and other noninvasive parameters used for evaluation of disease severity in patients with stable chronic heart failure (CHF). Endothelin-1 and big endothelin plasma concentrations were measured in 124 chronic heart failure patients. The second objective of the study was to prove an association between endothelin-1 and big endothelin plasma levels and two frequent polymorphisms in the endothelin-1 coding gene (6p21-23) -3A/-4A and G (8002) A in patients with chronic heart failure. Thirdly, we tried to associate other noninvasive parameters of CHF, especially cardiothoracic index (CTI), NYHA classification, signs of pulmonary congestion (PC) and ejection fraction (EF) with determined genotypes of the two ET-1 polymorphic variants. There were significant differences between big endothelin levels in NYHA II versus IV (P<0.001) and NYHA III versus IV (P<0.001) and endothelin-1 in NYHA II versus IV (P<0.001) and NYHA III versus IV (P<0.001). No associations between plasma levels of endothelin-1 and big endothelin and polymorphisms G (8002) A and -3A/-4A in gene coding endothelin-1 were found. In patients with CHF with CTI above 60% the number of carriers of genotypes with ET-1 8002A (AA and AG genotypes) increases. Concerning on the -3A/-4A ET-1 polymorphism, we observed a significant difference in genotype distribution as well as in allelic frequency in the group of patients with CTI above 60% between patients without and with pulmonary congestion. The allelic frequency of 3A allele is twice elevated in the patients with pulmonary congestion (37.8 vs. 78.1%, respectively).

Topics: Analysis of Variance; Cardiac Output, Low; Chi-Square Distribution; Chronic Disease; Endothelin-1; Endothelins; Female; Genotype; Humans; Male; Middle Aged; Polymorphism, Genetic; Protein Precursors; Risk Factors

Endothelin (ET) and natriuretic peptides have prognostic significance in chronic heart failure (CHF). Because stimuli for forming these neurohormones differ, this study investigates whether their prognostic power depends on clinical stage and on length of the observation period.. Plasma big ET, B-type natriuretic peptide (BNP), N-terminal BNP (N-BNP), and N-terminal atrial natriuretic peptide (N-ANP), in addition to 11 clinical and hemodynamic variables, were obtained from 452 patients with left ventricular ejection fraction (LVEF)

Topics: Biomarkers; Cardiac Output, Low; Chronic Disease; Endothelin-1; Female; Humans; Male; Middle Aged; Multivariate Analysis; Natriuretic Peptides; Prognosis; Risk Factors; Ventricular Dysfunction, Left

The aim of this study was to focus on the relationship among the associated genotypes of G (8002) A and -3A/-4A endothelin-1 (ET-1) gene polymorphisms and some clinical and/or biochemical parameters in Czech (Caucasian) patients with chronic heart failure. Included in the study were 103 patients with chronic heart failure (functional classes NYHA II-IV, ejection fraction < 40%). The ET-1 gene polymorphisms were detected by polymerase chain reaction (PCR) and restriction fragment length polymorphism methods. A significant decrease in the ET-1-associated genotype AG3A4A number (double heterozygote) was observed in CHF patients with plasma big endothelin levels above 0.7 pmol/L compared to those with levels below 0.7 pmol/L (OR = 0.19; 95% confidence interval = 0.06-0.57; P = 0.005; Pcorr = 0.03). We found a significant decrease in the AG3A4A genotype number in the other groups compared to the group of patients with both big endothelin and endothelin-1 levels under 0.7 pmol/L (OR = 0.22; 95% confidence interval = 0.07-0.79; P = 0.02). The double heterozygote variants of two ET-1 gene polymorphisms were associated with significantly less risk for chronic heart failure with higher levels of big endothelin.

Topics: Adult; Aged; Aged, 80 and over; Cardiac Output, Low; Endothelin-1; Endothelins; Female; Genotype; Humans; Male; Middle Aged; Polymorphism, Genetic; Protein Precursors; Risk Factors

Adult cardiac myocytes are terminally differentiated cells that are no longer able to divide. Accumulating data support the idea that apoptosis in these cells is involved in the transition from cardiac compensation to decompensated heart failure. Since a number of neurohormonal factors are activated in this state, these factors may be involved in the positive and negative regulation of apoptosis in cardiac myocytes. beta1-Adrenergic receptor and angiotensin type 1 receptor pathways, nitric oxide and natriuretic peptides are involved in the induction of apoptosis in these cells, while alpha1- and beta2-adrenergic receptor and endothelin-1 type A receptor pathways and gp130-related cytokines are antiapoptotic. The myocardial protection of the latter is mediated, at least in part, through mitogen-activated protein kinase-dependent pathways, compatible with the findings in other cell types. In contrast, signaling pathways leading to apoptosis in cardiac myocytes are distinct from those in other cell types. The cAMP/PKA pathway induces apoptosis in cardiac myocytes and blocks apoptosis in other cell types. The p300 protein, a coactivator of p53, mediates apoptosis in fibroblasts but appears to play a protective role in differentiated cardiac myocytes. The inhibition of myocardial cell apoptosis in heart failure may be achieved by directly blocking apoptosis signaling pathways or by modulating neurohormonal factors involved in their regulation. These may provide novel therapeutic strategies in some forms of heart failure.

Topics: Angiotensin II; Animals; Apoptosis; Cardiac Output, Low; Cytokines; Endothelin-1; Heart; Myocardium; Neurotransmitter Agents; Receptors, Adrenergic

Endothelin-1 (ET-1) is elevated in chronic heart failure (CHF). In this study, we determined the effects of chronic ET-1 blockade on renal sympathetic nerve activity (RSNA) in conscious rabbits with pacing-induced CHF. Rabbits were chronically paced at 320--340 beats/min for 3--4 wk until clinical and hemodynamic signs of CHF were present. Resting RSNA and arterial baroreflex control of RSNA were determined. Responses were determined before and after the ET-1 antagonist L-754,142 (a combined ET(A) and ET(B) receptor antagonist, n = 5) was administered by osmotic minipump infusion (0.5 mg. kg(-1) x h(-1) for 48 h). In addition, five rabbits with CHF were treated with the specific ET(A) receptor antagonist BQ-123. Baseline RSNA (expressed as a percentage of the maximum nerve activity during sodium nitroprusside infusion) was significantly higher (58.3 +/- 4.9 vs. 27.0 +/- 1.0, P < 0.001), whereas baroreflex sensitivity was significantly lower in rabbits with CHF compared with control (3.09 +/- 0.19 vs. 6.04 +/- 0.73, P < 0.001). L-754,142 caused a time-dependent reduction in arterial pressure and RSNA in rabbits with CHF. In addition, BQ-123 caused a reduction in resting RSNA. For both compounds, RSNA returned to near control levels 24 h after removal of the minipump. These data suggest that ET-1 contributes to sympathoexcitation in the CHF state. Enhancement of arterial baroreflex sensitivity may further contribute to sympathoinhibition after ET-1 blockade in heart failure.

Topics: Acetamides; Animals; Antihypertensive Agents; Arteries; Baroreflex; Blood Pressure; Cardiac Output, Low; Chronic Disease; Endothelin Receptor Antagonists; Endothelin-1; Kidney; Peptides, Cyclic; Rabbits; Receptor, Endothelin A; Sympathetic Nervous System; Time Factors

Endothelin-1 (ET-1) and adrenomedullin (ADM) are both produced in the arterial wall, but have opposing biological actions. Evidence from experimental animals suggests a functional interaction between ET-1 and ADM. We have tested this in humans. Small resistance arteries were obtained from gluteal biopsies taken from patients with chronic heart failure (CHF) due to coronary heart disease (CHD), or with CHD and preserved ventricular function. The contractile responses to big ET-1 and to ET-1 in both sets of vessels were studied in the absence (control) and presence of ADM at 20 pmol/l (low ADM) or 200 pmol/l (high ADM), using wire myography. ADM did not affect the conversion of big ET-1 into ET-1 in vessels from patients with either CHD or CHF. Low ADM did not alter the contractile response to ET-1 in vessels from patients with CHF. Low ADM was not tested in vessels from patients with CHD, but high ADM did not affect this response in arteries from these patients. High ADM did, however, significantly reduce the vasoconstrictor effect of ET-1 in vessels from patients with CHF. The maximum response, as a percentage of the response to high potassium, was 199% (S.E.M. 25%) in the control experiments (n=14), 205% (27%) in the low-ADM (n=7) studies and 150% (17%) in the high-ADM (n=6) experiments (P<0.001). Furthermore, the Hill coefficient increased from 0.57+/-0.05 in the absence of ADM to 1.16+/-0.15 in the high-ADM experiments, indicating that ADM at 200 pmol/l specifically antagonized one receptor type in vessels from patients with CHF. We conclude that there is a one-site receptor interaction between ADM and ET-1 that is specific for vessels from patients with CHF. This functional interaction between ADM and ET-1 in resistance arteries may be of pathophysiological importance in CHF.

Topics: Adrenomedullin; Analysis of Variance; Cardiac Output, Low; Case-Control Studies; Coronary Disease; Dose-Response Relationship, Drug; Endothelin-1; Female; Humans; Male; Myography; Peptides; Receptors, Endothelin; Vascular Resistance; Vasoconstriction; Vasodilator Agents

Chronic heart failure (CHF) studies investigating the clinical, hemodynamic, and therapeutic importance of endothelin-1 (ET-1), atrial natriuretic peptide (ANP), and brain natriuretic peptide (BNP) are largely based on resting plasma levels, which may vary with prior exertion and postprandial status. This study investigated the importance of peak-exercise plasma levels of ET-1, ANP, and BNP in the assessment of left ventricular (LV) systolic function. Thirty-six male-patients ages 58 +/- 10 (mean +/- SD ) with NYHA class I-IV CHF due to coronary artery disease or idiopathic dilated cardiomyopathy were enrolled. LV systolic function was assessed by echocardiography and radionuclide ventriculography. Resting and peak cardiopulmonary exercise venous blood sampling and treadmill exercise testing were performed in the fasting state. Resting plasma levels of ET-1, ANP, and BNP were elevated compared with reference laboratory normal values. Exercise induced significant (p < 0.0001) increase in plasma levels of ET-1, ANP, and BNP. On univariate analysis peak-exercise plasma levels of ET-1, ANP, and BNP were more closely related to echocardiographically determined LV end-diastolic diameter and end-systolic diameter than their resting values. Multiple step-wise regression models identified resting and peak-exercise plasma levels of ET-1 and ANP but only the resting BNP as independent predictors of LV dimensions and systolic function. Peak exercise plasma levels of ANP and ET-1 are potentially more reliable and important than their resting levels as markers of LV systolic dysfunction and LV dimensions in patients with heart failure.

Topics: Aged; Atrial Natriuretic Factor; Cardiac Output, Low; Echocardiography; Endothelin-1; Exercise; Fasting; Humans; Male; Middle Aged; Natriuretic Peptide, Brain; Regression Analysis

To study the importance of endothelin-1-induced vasoconstriction in a model of acute and maintained low cardiac output, by investigating regional changes within the mesenteric and particularly the intestinal mucosal circulation.. Prospective, controlled animal study.. University-affiliated research laboratory.. Thirteen fasted, anesthetized, mechanically ventilated landrace pigs.. Cardiac output, portal venous blood flow, renal arterial flow, jejunal mucosal microcirculation by laser Doppler flowmetry, jejunal capnotonometry (Pco2 gap), and jejunal mucosal oxygenation (tPo2) were monitored. Cardiac tamponade was established to reduce portal venous blood flow to a preset end point at two thirds of baseline. Measurements were made at baseline, after 90 mins of cardiac tamponade, and 90 mins after the administration of the combined endothelinA/endothelinB antagonist tezosentan at 1 mg.kg-1.hr-1 during tamponade in seven animals. Six animals served as time controls and received only the vehicle. Cardiac tamponade decreased portal venous blood flow, renal arterial flow, and laser Doppler flowmetry, whereas the Pco2 gap increased. The change in tPo2 failed to gain statistical significance (p =.08). Administration of tezosentan during tamponade restored portal venous blood flow and laser Doppler flowmetry to baseline values, increased tPo2 above baseline, and decreased Pco2 gap. No effect on renal arterial flow was observed. Investigated variables remained unchanged in control animals after induction of cardiac tamponade.. Endothelin-1 blockade in acute cardiac failure improves mesenteric, but not renal, perfusion, illustrating the regional importance of endothelin-1-induced vasoconstriction. Importantly, endothelin-1 blockade restored mucosal blood flow and oxygenation, which might be particularly interesting considering the implications for maintenance of mucosal barrier integrity in low output states.

Topics: Animals; Blood Gas Analysis; Cardiac Output, Low; Endothelin Receptor Antagonists; Endothelin-1; Female; Hemodynamics; Hydrogen-Ion Concentration; Male; Oximetry; Perfusion; Pyridines; Splanchnic Circulation; Swine; Tetrazoles; Vasoconstriction; Vasodilator Agents

Endothelin-1 (ET-1) is a potent positive inotrope in vitro, but its physiological effects on intrinsic myocardial contractile function in humans in vivo are unknown. Plasma ET-1 levels are elevated in heart failure, and ET-1 may be involved in the pathophysiology of this condition. However, its effects on contractile function of the failing human heart are also unknown.. A specific ET(A) receptor antagonist, BQ123, was infused (40 nmol/min, 16 minutes) into the left coronary artery in 8 patients with atypical chest pain (normal left ventricular ¿LV function and coronary arteries) and 8 patients with nonischemic dilated cardiomyopathy (DCM) who were undergoing diagnostic catheterization. In normal subjects, BQ123 rapidly induced a significant reduction in LV dP/dt(max) (-270+/-71 mm Hg/s after 16 minutes; P<0.05) and in LV dP/dt at a developed pressure of 40 mm Hg (LV dP/dt(40)) (-179+/-54 mm Hg/s; P<0.05). In DCM patients, however, BQ123 caused no reductions in LV dP/dt(max) (62+/-49 mm Hg/s after 16 minutes) or LV dP/dt(40) (83+/-51 mm Hg/s;P<0.05 compared with normal subjects). BQ123 had no effect on heart rate, LV relaxation, LV end-diastolic pressure, right atrial pressure, or pulmonary pressure in either patient group.. Endogenous ET-1 has a tonic positive inotropic effect in normal subjects, independent of effects on the peripheral vasculature and unmasked by inhibition of ET(A) receptors. However, the effect of short-term ET(A) blockade in DCM patients was opposite to that in normal subjects, which suggests that ET-1 may cause negative inotropic effects in the failing heart.

Topics: Adult; Cardiac Output, Low; Cardiomyopathy, Dilated; Chest Pain; Coronary Vessels; Endothelin Receptor Antagonists; Endothelin-1; Female; Humans; Injections; Male; Middle Aged; Myocardial Contraction; Peptides, Cyclic; Receptor, Endothelin A; Reference Values

Only scarce information is available on the activity and modifications of the cardiac endothelin (ET)-1 system in heart failure due to ischemic (ICM) or idiopathic dilated (DCM) cardiomyopathy. The activity of the ET-1 system was investigated by measuring cardiac ET-1 and big ET-1 formation and quantifying cardiac mRNA for prepro-ET-1 (ppET-1), ET-converting enzyme-1, and ET(A) and ET(B) receptors both in myocardium and in isolated myocytes using Northern blot, reverse transcription-polymerase chain reaction, and in situ hybridization in 22 patients with DCM and 20 with ICM who underwent cardiac transplantation and in 7 potential heart transplant donors (nonfailing hearts). Notwithstanding a similar increase of plasma ET-1 in the 2 groups, cardiac ET formation, mRNA levels for ppET-1, and ET(A) and ET(B) receptors were higher on both the myocardium and isolated myocytes from ICM than on those from DCM hearts (P<0.001 for all). ppET-1 and ET-converting enzyme-1 mRNAs were expressed on myocytes and endothelial and interstitial cells in ICM, whereas in DCM and nonfailing hearts they were mainly expressed on nonmyocyte cells. In both ICM and DCM, the ET(A) mRNA signal was expressed on both myocytes and nonmyocyte cells, whereas ET(B) mRNA was almost exclusively localized on nonmyocyte cells. ET(A)- and ET(B)-specific receptor binding was increased on both myocytes and cardiac membranes, showing a positive correlation with left ventricular ejection fraction in ICM (r=0.78 and 0.70) but not in DCM patients. The present results show that human ventricular myocytes express all of the components of the ET-1 system, which is selectively upregulated in ICM patients and appears to be functionally important in the maintenance of cardiac function.

Topics: Adult; Aged; Aspartic Acid Endopeptidases; Cardiac Output, Low; Cardiomyopathy, Dilated; Endothelin-1; Endothelin-Converting Enzymes; Endothelins; Female; Humans; Male; Metalloendopeptidases; Middle Aged; Myocardial Ischemia; Myocardium; Protein Precursors; Radioligand Assay; Receptor, Endothelin A; Receptor, Endothelin B; Receptors, Endothelin; RNA, Messenger; Up-Regulation

Alterations of vasoreactivity are a well-known phenomenon in chronic heart failure (CHF), and activation of the endogenous endothelin (ET) system is suspected to contribute significantly. Regional differences in alterations of vasoreactivity exist; however, nothing is known about cerebrovascular reactivity in CHF. This is of interest in view of increased stroke risk in CHF. Therefore, 12 weeks after coronary artery ligation to induce CHF in rats, studies of vasoreactivity of the isolated basilar artery (BA) were performed and compared with third-order branches (MA-A3) and the main trunk (MA) of the superior mesenteric artery. Some of the animals received long-term ET-receptor antagonism by 11 weeks of treatment with the selective ET(A)-receptor antagonist LU 135252 or the mixed ET(A)/ET(B)-receptor antagonist bosentan. In rats with CHF, endothelium-dependent relaxation by acetylcholine and A23187 as well as endothelium-independent relaxation by sodium nitroprusside (SNP) was largely unaffected in BA or MA. However, in MA-A3, potency of SNP was diminished without change of maximal effect. ET-1-induced contraction did not differ in arteries from CHF and control rats, either in placeboor ET-receptor antagonist-treated animals. In summary, there was essentially no change of vascular reactivity in similar sized arteries obtained from brain and mesentery. This is in contrast to results on arteries from a variety of vascular regions published previously, thus supporting the concept of organ- and probably time-related changes of vascular function in the development of CHF. The absence of significant alteration of cerebral vasoreactivity may be taken to indicate that changes in cerebral blood flow and increased incidence of ischemic stroke in patients with CHF are caused not by local alterations of vascular function.

Topics: Acetylcholine; Animals; Basilar Artery; Calcimycin; Cardiac Output, Low; Chronic Disease; Endothelin Receptor Antagonists; Endothelin-1; Endothelium, Vascular; Male; Mesenteric Arteries; Nitroprusside; Rats; Rats, Wistar; Vasoconstriction; Vasodilation; Vasodilator Agents

The renin-angiotensin system and endothelin are important regulators of the cardiovascular system. Although increased production of endothelin-1 (ET-1) is reported in patients with heart failure, the detailed mechanism remains to be determined. To elucidate the relationship between the renin-angiotensin system and ET-1 in hypertensive heart failure, we evaluated the effects of long-term treatment with imidapril, an angiotensin converting enzyme (ACE) inhibitor, on preproET-1, endothelin A receptor (ETAR), and ACE mRNA expression in the left ventricle and evaluated these in relation to myocardial remodeling in the failing heart of Dahl salt-sensitive (DS) hypertensive rats fed a high salt diet. In DS rats fed an 8% NaCl diet after the age of 6 weeks, a stage of concentric left ventricular hypertrophy at 11 weeks (DSLVH) was followed by a distinct stage of left ventricular failure with chamber dilatation at 18 weeks (DSHF). Imidapril (DSHF-IM, n = 8, 1 mg/kg/day, subdepressor dose) or vehicle (DSHF-V, n = 8) was given from stage DSLVH to DSHF for 7 weeks, and age-matched (18 weeks) Dahl salt-resistant rats fed the same diet served as the control group (DR-C, n = 8). In both groups, blood pressure was similar and significantly higher than in DR-C. Markedly increased left ventricular end-diastolic diameter and reduced fractional shortening in DSHF-V was significantly ameliorated in DSHF-IM using transthoracic echocardiography. The preproET-1, ETAR, and ACE mRNA levels in the left ventricle were significantly increased in DSHF-V compared with DR-C, and significantly suppressed in DSHF-IM compared with DSHF-V. DSHF-V demonstrated a significant increase in the wall-to-lumen ratio and perivascular fibrosis in coronary arterioles, and myocardial fibrosis, with all these parameters being significantly improved by imidapril. In conclusion, myocardial remodeling and heart failure in DS rats fed a high salt diet were significantly ameliorated by a subdepressor dose of imidapril, which may be attributable to a decrease in ET-1 mRNA expression and angiotensin II in the left ventricle.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Body Weight; Cardiac Output, Low; Endothelin-1; Endothelins; Gene Expression; Heart Ventricles; Hemodynamics; Hypertension; Imidazoles; Imidazolidines; Male; Myocardial Contraction; Myocardium; Organ Size; Peptidyl-Dipeptidase A; Protein Precursors; Rats; Rats, Inbred Dahl; Receptor, Endothelin A; Receptors, Endothelin; RNA, Messenger; Ventricular Remodeling

The development of pulmonary hypertension (PH) causes right-sided heart failure. We investigated whether chronic treatment with the endothelin-A- (ETA) receptor antagonist BMS-193884 in rats with monocrotaline- (MCT) induced PH improves right-sided heart failure. Administration of BMS-193884 (100mg/kg) was commenced on the day before treatment with MCT. At 19 days, hemodynamics were measured under anesthesia and hearts were removed. The right ventricular systolic pressure (RVSP), an indicator for pulmonary hypertension, was remarkably elevated in the PH group compared with the normal control group. BMS-193884 effectively prevented this elevation. The central venous pressure, an indicator for right-sided heart failure, was markedly increased in the PH group. This increase was reduced to the normal level by BMS-193884. In the failing right ventricle of the PH group, the expression of atrial natriuretic peptide (ANP) mRNA, which is a molecular marker for the failing heart, was markedly increased. BMS-193884 greatly prevented this increase. The present study suggests that ET-1 contributes to the right-sided heart failure caused by PH and that an ETA-receptor antagonist is a beneficial drug which improves both hemodynamics and cardiac gene expression in the failing right ventricle.

Topics: Animals; Cardiac Output, Low; Endothelin Receptor Antagonists; Endothelin-1; Hypertension, Pulmonary; Male; Monocrotaline; Oxazoles; Rats; Rats, Wistar; Receptor, Endothelin A; Sulfonamides

Endothelin (ET)-1 has a positive inotropic effect and induces hypertrophy in cardiomyocytes. We previously reported that the peptide level of ET-1 is increased in the failing heart of rats with chronic heart failure (CHF) and that treatment with an ETA-receptor antagonist greatly improves survival in rats with CHF. However, precise analysis for alteration of the myocardial ET system in the failing heart is not known. In this study, we used rats with CHF due to chronic myocardial infarction. Sham-operated rats served as a control. The results showed that the level of preproendothelin (preproET)-1 mRNA and the peptide level of ET-1 were markedly increased in the heart of rats with CHF, whereas the expression of endothelin-converting enzyme (ECE)-1 mRNA in the heart did not differ between CHF and control rats. The intensity of ET-1 staining (ET-1-like immunoreactivity) in cardiomyocytes was markedly stronger in rats with CHF than in control rats, and the fibrotic tissues of the infarcted area were not stained. The mRNA and protein levels of both ETA and ETB receptors in the heart were significantly higher in rats with CHF than in control rats. The present study suggests that the increase in ET-1 peptide level in the heart of the rats with CHF originated from upregulation of preproET-1 mRNA, which was not attendant with the alteration of ECE-1 mRNA expression, and that both the ETA- and ETB-receptor systems are greatly accelerated in the failing heart.

Topics: Animals; Aspartic Acid Endopeptidases; Cardiac Output, Low; Endothelin-1; Endothelin-Converting Enzymes; Endothelins; Male; Metalloendopeptidases; Myocardium; Protein Precursors; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Receptor, Endothelin B; Receptors, Endothelin; Reference Values; RNA, Messenger; Tissue Distribution

An activated endothelin (ET) system may be of pathophysiological relevance in human heart failure. We characterized the functional effects of ET-1, ET receptors, and ET-1 peptide concentration in left ventricular myocardium from 10 nonfailing hearts (NF) and 27 hearts in end-stage failure due to idiopathic dilative cardiomyopathy (DCM).. Inotropic effects were characterized in isolated muscle strips (1 Hz; 37 degrees C). ET-1 0.0001 to 0.3 micromol/L significantly (P<0.05) increased twitch force by maximally 59+/-10% in NF and by 36+/-11% in DCM (P<0.05 versus NF). Preincubation with propranolol 1 micromol/L and prazosin 0.1 micromol/L did not affect the response to ET-1, but the mixed ET receptor antagonist bosentan and the ETA receptor antagonist BQ-123 shifted the concentration-response curves for ET-1 rightward. The ETB receptor agonist sarafotoxin S6c 0.001 to 0.3 micromol/L had no functional effects. The inotropic response to ET-1 was not associated with increased intracellular Ca2+ transients, as assessed in aequorin-loaded muscle strips. ET receptor density (Bmax; radioligand binding) was 62.5+/-12.5 fmol/mg protein in NF and 122. 4+/-24.3 fmol/mg protein in DCM (P<0.05 versus NF). The increase in Bmax in DCM resulted from an increase in ETA receptors without change in ETB receptors. ET-1 peptide concentration (radioimmunoassay) was higher in DCM than in NF (14 447+/-2232 versus 4541+/-1340 pg/mg protein, P<0.05).. ET-1 exerts inotropic effects in human myocardium through ETA receptor-mediated increases in myofibrillar Ca2+ responsiveness. In DCM, functional effects of ET-1 are attenuated, but ETA receptor density and ET-1 peptide concentration are increased, indicating an activated local cardiac ET system and possibly a reduced postreceptor signaling efficiency.

Topics: Aequorin; Calcium; Cardiac Output, Low; Cardiomyopathy, Dilated; Endothelin Receptor Antagonists; Endothelin-1; Humans; In Vitro Techniques; Luminescent Measurements; Myocardial Contraction; Myocardium; Peptides, Cyclic; Receptors, Endothelin; Reference Values

The current study addresses the functional status and role of the endothelin ET(A) receptor for renal vascular function in rabbits with and without heart failure (epinephrine-induced cardiomyopathy). Under baseline conditions, the ET(A) receptor antagonist BQ-123 did not change basal renal hemodynamics, but completely prevented endothelin-1 (ET-1)-induced renal vasoconstriction. In heart failure, in the presence of elevated plasma ET-1 concentrations (P < .05), renal vasoconstriction in response to exogenous ET-1 was intact. Unlike under baseline conditions, ET(A) receptor antagonism markedly increased renal blood flow (P <.05) and decreased renal vascular resistance (P < .05) in heart failure. The current study provides new insight into the pathophysiology of renal vasoconstriction associated with heart failure and the specific role of the renal ET(A) receptor in this pathophysiologic adaptation.

Topics: Adrenergic Agonists; Animals; Cardiac Output, Low; Chinchilla; Endothelin Receptor Antagonists; Endothelin-1; Epinephrine; Hemodynamics; Male; Neurotransmitter Agents; Peptides, Cyclic; Rabbits; Receptor, Endothelin A; Receptors, Endothelin; Renal Circulation; Vasoconstriction; Ventricular Dysfunction, Left

Topics: Animals; Cardiac Output, Low; Endothelin-1; Humans; Lung; Metabolic Clearance Rate

The pulmonary vascular bed is a major site for endothelin-1 (ET-1) clearance. A reduced clearance could contribute to the increase in circulating ET-1 levels found in heart failure (HF). We therefore evaluated the effect of HF on pulmonary ET-1 clearance and on plasma ET-1 concentrations.. Rats with myocardial infarction (n=24) were compared with sham-operated rats (n=22). The lungs were isolated and perfused at a constant flow rate of 10 mL/min. Pulmonary ET-1 clearance was measured by the single-bolus indicator-dilution technique with 125I-labeled ET-1. Infarct rats developed HF with mild pulmonary hypertension. ET-1 extraction was reduced by HF from 63+/-1.5% to 41+/-4.5% (mean+/-SEM, P<0.001). Mixed venous (MV) and aortic ET-1 levels doubled with HF. There was a plasma ET-1 gradient across the lungs of sham rats (MV-aortic levels, 0.21+/-0.12 pg/mL) but not in lungs of HF rats (0.01+/-0.17 pg/mL). Plasma ET-1 levels correlated closely and inversely with ET-1 extraction (P<0.001).. HF is associated with reduced pulmonary ET-1 clearance that contributes to the increase in circulating levels.

Topics: Animals; Cardiac Output, Low; Endothelin-1; Lung; Male; Metabolic Clearance Rate; Myocardial Infarction; Rats; Rats, Wistar

Patients with chronic heart failure show impairment of ventilatory efficiency, defined as the relation between ventilation and carbon dioxide output. It is caused by ventilation of excess physiologic dead space. We hypothesized a role of active vasoconstriction in the increase of physiologic dead space, presumed to lead to alveolar hypoperfusion.. In 57 patients with chronic heart failure (New York Heart Association classification II through IV, ejection fraction 25.6%+/-10.4%) and 7 control subjects, gas exchange at rest and on exercise was compared with hemodynamic measurements and, in a subgroup of 15 patients, with endothelin-1, epinephrine, and norepinephrine levels in the pulmonary and systemic circulation. Ventilatory efficiency at rest (VE/VCO2 ratio) correlated with ventilatory efficiency on exercise (VE vs VCO2 slope). Impairment of ventilatory efficiency correlated strongly negative with exercise tolerance (maximal oxygen uptake: r = -0.67) and cardiac output (r = -0.66) and positive with pulmonary hypertension (mean pulmonary artery pressure: r = 0.69, pulmonary vascular resistance: r = 0.60). None of the vasoconstrictors correlated with reduction of ventilatory efficiency in the subgroup studied.. Impairment of ventilatory efficiency in chronic heart failure is correlated with resting pulmonary artery pressures and associated with the impairment of exercise capacity. An imbalance of pulmonary vascular tone probably leads to both pulmonary hypertension and alveolar hypoperfusion.

Topics: Adult; Cardiac Output, Low; Case-Control Studies; Endothelin-1; Epinephrine; Exercise Test; Female; Hemodynamics; Humans; Lung; Male; Middle Aged; Pulmonary Gas Exchange; Vasoconstriction; Ventilation-Perfusion Ratio

We tested the hypothesis that, in patients with stable heart failure, measuring big endothelin-1 (ET-1) plasma level at rest predicts short-term prognosis better than peak oxygen consumption (VO2max) at exercise.. Cardiopulmonary exercise testing and evaluation of neurohumoral plasma factors are established tools to estimate survival in patients with heart failure. No data, however, exist comparing the prognostic value of both marker categories simultaneously.. Two hundred twenty-six heart failure patients were studied in regard to a combined end point of death and prioritization for urgent cardiac transplantation within 1 year follow-up.. During the study period 149 patients were without cardiac events (group A), 69 patients died or were urgently transplanted (group B) and 8 patients were alive after a nonurgent heart transplant operation. Norepinephrine (p < 0.0001), atrial natriuretic peptide (p < 0.001), big endothelin plasma levels (p < 0.0001 as well as workload, VO2max and achieved percentage of predicted peak oxygen consumption (pVO2max) (all p < 0.0001) differed significantly between groups A and B. In multivariate stepwise regression analysis, however, only big ET-1 plasma concentration (chi2=74.4, p < 0.0001), New York Heart Association function class (chi2=33.9, p < 0.0001), maximal workload (chi2=7.2, p < 0.01, and plasma atrial natriuretic peptide (ANP) concentration (chi2=4.6, p < 0.05) were independently related to outcome. Peak oxygen consumption or pVO2max did not reach statistical significance in this model. Event-free survival rates were significantly lower in patients with a big ET-1 level of 4.3 fmol/ml or more than with lower big ET-1 levels (p < 0.0001).. We conclude that in patients with chronic heart failure who are stable on oral therapy measuring big ET-1 and ANP plasma levels may be a valuable noninvasive adjunct to improve the prognostic accuracy of detecting high risk patients compared with exercise testing alone.

Topics: Adult; Aged; Cardiac Output, Low; Endothelin-1; Endothelins; Exercise Test; Female; Heart; Humans; Lung; Male; Middle Aged; Multivariate Analysis; Prognosis; Proportional Hazards Models; Protein Precursors; Risk Assessment; Survival Analysis; Time Factors

Occlusion of the diseased coronary artery in humans causes acute myocardial infarction, survivors of which have a high risk for the development of chronic heart failure. Cardiac myocytes and vascular endothelial cells produce endothelin-1 (refs 2-4), which increases the contractility of cardiac muscle and of vascular smooth muscle cells. Endothelin-1 also exerts long-term effects such as myocardial hypertrophy, and causes cellular injury in cardiac myocytes. Production of endothelin-1 is markedly increased in the myocardium of rats with heart failure, and acute application of an endothelin-receptor antagonist decreases myocardial contractility in such rats, indicating that myocardial endothelin-1 may help to support contractility of the failing heart. But we report here that the upregulated myocardial endothelin system may contribute to the progression of chronic heart failure, because long-term treatment with an endothelin-receptor antagonist greatly improved the survival of rats with chronic heart failure. This beneficial effect was accompanied by significant amelioration of left ventricular dysfunction and prevention of ventricular remodelling, in which there is usually an increase in the ventricular mass and cavity enlargement of the ventricle.

Topics: Animals; Cardiac Output, Low; Cardiomegaly; Endothelin Receptor Antagonists; Endothelin-1; Heart Ventricles; Hemodynamics; Male; Myocardial Infarction; Myocardium; Peptides, Cyclic; Rats; Receptor, Endothelin A; RNA, Messenger; Survival Analysis; Time Factors