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Query: UMLS:C0018801 (
heart failure
)
72,216
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Brain natriuretic peptide (BNP) gene expression accompanies cardiac hypertrophy and
heart failure
. The vasoconstrictor
endothelin-1
(ET) may be involved in the development of these diseases. ET has also been shown to activate phospholipase A(2) (PLA(2)), and the resulting metabolites are important second messengers. We studied how ET and PLA(2) metabolites regulate BNP gene expression. The human BNP (hBNP) promoter (from -1818 to +100) coupled to a luciferase reporter gene was transferred into neonatal ventricular myocytes (NVMs), and luciferase activity was measured as an index of promoter activity. ET induced BNP mRNA in NVMs as assessed by Northern blot. It also stimulated the hBNP promoter, an effect completely inhibited by actinomycin D. To test the involvement of different PLA(2) isoforms, transfected cells were treated with various PLA(2) inhibitors before stimulation with ET. Only Ca(2+)-independent PLA(2) blockade prevented ET-stimulated hBNP promoter activity. The PLA(2) metabolite lysophosphatidic acid (LPA) also activated the hBNP promoter, but arachidonic acid itself did not. ET regulation of the hBNP promoter is pertussis toxin-sensitive. The nonreceptor tyrosine kinase Src and the small GTPase Rac mediate the effects of both ET and LPA in stimulation of the hBNP promoter. We studied the involvement of cis elements in ET-stimulated hBNP promoter activity. Deletion of BNP promoter sequences from -1818 to -408 and from -408 to -40 reduced the effect of ET by 60% and 80%, respectively. Moreover, ET-stimulated luciferase activity was reduced by 50% when the proximal GATA element was mutated. These data suggest that (1) ET activates the hBNP promoter through a transcriptional mechanism; (2) LPA, perhaps generated by iPLA(2), is involved in the effect of ET; (3) Src and Rac mediate ET and LPA stimulation of the hBNP promoter; and (4) ET regulation of the hBNP promoter targets both distal and proximal cis elements.
...
PMID:Src and Rac mediate endothelin-1 and lysophosphatidic acid stimulation of the human brain natriuretic peptide promoter. 1123 Mar 22
Endothelin (ET) is a peptide composed of 21 amino acids, derived from a larger precursor, the big-endothelin, by action of the endothelin-converting enzyme (ECE) family; three isoforms of endothelin, named ET-1, ET-2 and ET-3, have been identified. Endothelin-1 is generated mainly by vascular endothelial cells and exerts various important biological actions, mediated by two receptor subtypes, ET-A and ET-B, belonging to the G protein-coupled family that have been identified in various human tissues such as the cardiac tissue. Endothelin-1 is a potent vasoconstrictive agent, has inotropic and mitogenic actions, modulates salt and water homeostasis and plays an important role in the maintenance of vascular tone and blood pressure in healthy subjects. Endothelin-1, as well as ET-A and ECE-1, also has an important role in cardiovascular development, as observed by the variety of abnormalities related to neural crest-derived tissues in mouse embryos deficient of a member of the ET-1/ECE-1/ET-A pathway. Various evidence indicates that endogenous
endothelin-1
may contribute to the pathophysiology of conditions associated with sustained vasoconstriction, such as
heart failure
. In
heart failure
, elevated circulating levels of both
endothelin-1
and big-
endothelin-1
are observed; in failing hearts an activation of the endothelin system is found: tissue level of ET-1 is increased with respect to non-failing hearts as well as receptor density, due mainly to an upregulation of the ET-A subtype, the prevalent receptor subclass in cardiac tissue. Finally, studies in both humans and animal models of cardiovascular disease show that inhibition of the endothelin function (anti-endothelin strategy) is associated with an improvement of haemodynamic conditions; these observations indicate that endothelin receptor antagonists or endothelin-converting enzyme inhibitors may constitute a novel and potentially important class of agents for the treatment of this disease.
...
PMID:The role of endothelins and their receptors in heart failure. 1124 12
The myocardial Na+/H+ exchange (NHE) represents a major mechanism for pH regulation during normal physiological processes but especially during ischaemia and early reperfusion. However, there is now very compelling evidence that its activation contributes to paradoxical induction of cell injury. The mechanism for this most probably reflects the fact that activation of the exchanger is closely coupled to Na+ influx and therefore to elevation in intracellular Ca2+ concentrations through the Na+/Ca2+ exchange. The NHE is exquisitely sensitive to intracellular acidosis; however, other factors can also exhibit stimulatory effects via phosphorylation-dependent processes. These generally represent various autocrine and paracrine as well as hormonal factors such as
endothelin-1
, angiotensin II and alpha1-adrenoceptor agonists, which probably act through receptor-signal transduction processes. Thus far, 6 NHE isoforms have been identified and designated as NHE1 through NHE6. All except NHE6, which is located intracellularly, are restricted to the sarcolemmal membrane. In the mammalian myocardium the NHE1 subtype is the predominant isoform, although NHE6 has also been identified in the heart. The predominance of NHE1 in the myocardium is of some importance since, as discussed in this review, pharmacological development of NHE inhibitors for cardiac therapeutics has concentrated specifically on those agents which are selective for NHE1. These agents, as well as the earlier nonspecific amiloride derivatives have now been extensively demonstrated to possess excellent cardioprotective properties, which appear to be superior to other strategies, including the extensively studied phenomenon of ischaemic preconditioning. Moreover, the salutary effects of NHE inhibitors have been demonstrated using a variety of experimental models as well as animal species suggesting that the role of the NHE in mediating injury is not species specific. The success of NHE inhibitors in experimental studies has led to clinical trials for the evaluation of these agents in high risk patients with coronary artery disease as well as in patients with acute myocardial infarction (MI). Recent evidence also suggests that NHE inhibition may be conducive to attenuating the remodelling process after MI, independently of infarct size reduction, and attenuation of subsequent postinfarction
heart failure
. As such, inhibitors of NHE offer substantial promise for clinical development for attenuation of both acute responses to myocardial as well as chronic postinfarction responses resulting in the evolution to
heart failure
.
...
PMID:The myocardial Na+/H+ exchanger: a potential therapeutic target for the prevention of myocardial ischaemic and reperfusion injury and attenuation of postinfarction heart failure. 1129 48
A role of the potent and long-acting vasoconstrictor peptide
endothelin-1
in the pathophysiology of chronic human
heart failure
has been postulated based on indirect evidence such as elevated plasma
endothelin-1
levels, their correlation with the degree of hemodynamic impairment, and their predictive value for patient survival. The advent of specific of endothelin-1 receptor antagonists has provided the opportunity to directly evaluate its pathophysiologic role and assess its potential role as a new approach to
heart failure
therapy. This review summarizes the evidence linking
endothelin-1
to the pathophysiology of chronic
heart failure
, and analyzes the clinical results obtained thus far in patients during acute intravenous, and more prolonged, oral administration of
endothelin-1
-receptor antagonists.
...
PMID:The role of endothelin receptor antagonists in the treatment of chronic heart failure. 1130 78
Endothelins are peptide tissue hormones with a powerful vasoconstrictor effect. The most important one among them,
endothelin-1
, is the most powerful vasoconstrictor substance in the human organism which causes constriction of the blood vessels, in particular renal, coronary, pulmonary and cerebral arteries, bronchioles, and inhibits the secretion of atrial natriuretic factor and vasopressin. Because of these effects importance in the pathogenesis of some diseases is ascribed to it, e.g. myocardial infarction,
cardiac failure
, asthma bronchiale, Raynaud a syndrome, renovascular disease, cyclosporin-induced nephrotoxicity and cerebrovascular attacks. Although there is little direct evidence on the role of endothelins in arterial hypertension, some authors prove its importance at least in some of its forms, e.g. salt sensitivity, or in complications of hypertension. The results of experimental and human studies with antagonists of endothelin receptors and endothelin-converting enzyme blockers also support the role of endothelin in the pathogenesis of hypertension. The use of these antagonists in the treatment of hypertension calls however for further long-term studies.
...
PMID:[Endothelins--physiology, pathophysiology and importance in arterial hypertension]. 1134 33
Congestive heart failure is a major issues for cardiologists and to fully understand
heart failure
, it is important to understand the mechanism of the development of cardiac hypertrophy. Hemodynamic overload, namely mechanical stress, is a major cause of cardiac hypertrophy and to dissect the signaling pathways from mechanical stress to cardiac hypertrophy, an in-vitro device by which mechanical stress can be imposed on cardiac myocytes of neonatal rats cultured in serum-free conditions has been developed. Passively stretching cardiac myocytes cultured on silicone membranes induced various hypertrophic responses, such as activation of the phosphorylation cascades of many protein kinases, expression of specific genes and an increase in protein synthesis. During this process, secretion and production of vasoactive peptides, such as angiotensin II and
endothelin-1
, were increased and they played critical roles in the induction of these hypertrophic responses. Candidates for the 'mechanoreceptor' that receives the mechanical stress and converts it into intracellular biochemical signals have been recently demonstrated. Gene therapy and cell transplantation are hopeful strategies for the treatment of
heart failure
and require an understanding of how normal cardiac myocytes are differentiated. A key gene that plays a critical role in cardiac development has been isolated. The cardiac homeobox-containing gene Csx is expressed in the heart and the heart progenitor cells from the very early developmental stage, and targeted disruption of the murine Csx results in embryonic lethality because of the abnormal looping morphogenesis of the primary heart tube. With a cardiac zinc finger protein GATA4, Csx induces cardiomyocyte differentiation of teratocarcinoma cells as well as upregulation of cardiac genes. Mutations of human CSX cause various congenital heart diseases including atrial septal defect, ventricular septal defect, tricuspid valve abnormalities and atrioventricular block.
...
PMID:Molecular mechanism of cardiac hypertrophy and development. 1134 34
Initial pharmacologic therapy for hypertension is low-dose thiazide diuretics, beta-blockers, and ACE inhibitors. Increasing data have confirmed that ACE inhibitors have specific benefit in patients with diabetes, atherosclerosis, left ventricular dysfunction, and renal insufficiency. CCBs are alternative agents for ISH in the elderly and appear to decrease stroke with perhaps less protection against progression of renal insufficiency and proteinuria, CAD mortality and new onset
heart failure
versus other initial agents, especially ACE inhibitors. ARBs are well tolerated and effective blood pressure lowering agents but have not been confirmed as effective as ACE inhibitors for reducing renal progression, clinical events, or mortality from
heart failure
. Effective pharmacologic antihypertensive therapy may avoid disabling and undetected cerebrovascular disease, cognitive dysfunction, and disturbing symptoms of elevated blood pressure. Vasopeptidase inhibitor, such as omapatrilat, and
endothelin-1
antagonist, such as bosentan, may become future agents approved for the reduction of morbidity and mortality with hypertension. The ALLHAT trial continues to examine the potential benefits and harms of amlodipine versus chlorthalidone and lisinopril in a diverse high-risk population. Based on ALLHAT data, however, doxazosin is no longer an acceptable initial pharmacological agent. Intensive pharmacologic treatment with blood pressure lowering to less than 130/85 mm Hg is recommended with diabetes, renal insufficiency, and
heart failure
with additional goal of less than 125/75 mm Hg with renal failure and proteinuria greater than 1 g/24 h, based on multiple outcome studies.
...
PMID:Update in pharmacologic treatment of hypertension. 1140 10
The combination of an angiotensin II receptor antagonist and a thiazide has been used extensively in the treatment of patients with overt
heart failure
. The effect of this combination on the vascular wall early in the disease, however, has not been investigated. To evaluate this effect, the vascular status of 3-month-old cardiomyopathic hamsters was assessed after daily administration of a combination of losartan (25 mg/kg, p.o.) and hydrochlorothiazide (6.5 mg/kg, p.o.) over an 8-week period. Age-matched golden hamsters were used as healthy controls. The contractile response of aortic rings to
endothelin-1
was significantly higher in cardiomyopathic hamsters than in control animals. Concentration-response curves for the
endothelin-1
-induced contraction were displaced to the right after hydrochlorothiazide+losartan treatment (toward the curves for healthy controls); however, E(max) from treated hamsters was significantly reduced when compared to E(max) from untreated cardiomyopathic animals (1.016+/-0.073 vs. 1.346+/-0.153 g, P<0.05, n=6). No significant differences in the EC50 values from these curves were observed between hydrochlorothiazide+losartan treated and untreated cardiomyopathic animals (2.90+/-0.95 vs. 1.10+/-0.85 nM, P>0.05). The acetylcholine-induced relaxation observed in cardiomyopathic animals was not improved after treatment with hydrochlorothiazide+losartan or hydrochlorothiazide alone, but the combination of these drugs increased significantly the basal production of nitric oxide (NO). Angiotensin-converting enzyme activity increased in plasma (from 29.9+/-1.23 to 41.16+/-1.82 nmol x mg(-1) x min(-1), n=8, P<0.05) but decreased in the aorta (from 0.33+/-0.02 to 0.25+/-0.017 nmol x mg(-1) x min(-1), n=6, P<0.05) after treatment with hydrochlorothiazide+losartan. In addition, the combination of these drugs reduced the heart-to-body mass ratio (3.96+/-0.07 for treated vs. 5.01+/-0.20 mg/g for untreated animals, n=7, P<0.05), and the thickness of the aortic media (0.076+/-0.003 for treated vs. 0.149+/-0.009 mm for untreated animals, n=8, P<0.05). Although hydrochlorothiazide alone lowered systolic blood pressure to the same level achieved with both drugs in combination (from 166+/-10 for untreated cardiomyopathic animals to 84+/-1 mm Hg for hydrochlorothiazide+losartan, and 80+/-5 mm Hg for hydrochlorothiazide alone, P<0.05), no significant reduction in heart-to-body mass ratio was observed in animals treated with the diuretic alone (P>0.05). In conclusion, in this model of
heart failure
, chronic hydrochlorothiazide+losartan administration normalizes the vascular responses to
endothelin-1
, improves basal vascular tone, and prevents the development of cardiac and vascular hypertrophy.
...
PMID:Chronic administration of losartan plus hydrochlorothiazide improves vascular status in young cardiomyopathic hamsters. 1140 35
Increases in the expression of
endothelin-1
(
ET-1
) in cardiac myocytes play a critical role in the development of
heart failure
in vivo. Whereas norepinephrine (NE) is a potent inducer of
ET-1
expression in cardiac myocytes, the signaling pathways that link NE to inducible cardiac
ET-1
expression are unknown. Adrenergic stimulation results in an increase in intracellular calcium levels, which in turn activates calcineurin. Here, we have shown that stimulation with NE markedly increased the expression of the
ET-1
gene in primary cardiac myocytes from neonatal rats. This increase was severely attenuated by a beta-adrenergic antagonist, metoprolol, but not by an alpha-adrenergic antagonist, prazosin. Consistent with these data, the beta-adrenergic agonist isoproterenol (ISO) activated the rat
ET-1
promoter activity to an extent that was similar to NE. The ISO-stimulated increase in promoter activity was significantly inhibited by a Ca(2+)-antagonist, nifedipine, and an immunosuppressant, cyclosporin A, which blocks calcineurin. Mutation analysis indicated that the GATA4 binding site is required for ISO-responsive
ET-1
transcription. Stimulation with ISO enhanced the interaction between NFATc and GATA4 in cardiac myocytes. Consistent with this interaction, overexpression of GATA4 and NFATc synergistically activated the
ET-1
promoter. These findings demonstrate that NE-stimulated
ET-1
expression in cardiac myocytes is mediated predominantly via a beta-adrenergic pathway, and that calcium-activated calcineurin-GATA4 plays a role in this process.
...
PMID:Calcineurin-GATA4 pathway is involved in beta-adrenergic agonist-responsive endothelin-1 transcription in cardiac myocytes. 1143 16
A role of the potent and long-acting vasoconstrictor peptide
endothelin-1
and the pathophysiology of chronic human
heart failure
has been postulated based upon indirect evidence such as elevated plasma
endothelin-1
levels and their with the degree of hemodynamic impairment. The advent of specific of endothelin-1 receptor antagonists has provided the opportunity not only to directly evaluate its pathophysiological role but also to assess its potential role as a new approach to
heart failure
therapy. This brief review summarizes the evidence linking
endothelin-1
to the pathophysiology of chronic
heart failure
and the clinical results obtained in patients during acute, intravenous and more prolonged, oral administration with bosentan, a mixed ET(A)/ET(B)-receptor antagonist. Bosentan acutely and during short-term oral therapy markedly improved hemodynamics in patients in addition to standard
heart failure
therapy, including an ACE-inhibitor. These effects were associated with a reduced responsiveness of the renin-angiotensin system to diuretic therapy and reduced basal plasma aldosterone levels. Although the hemodynamic and neurohumoral profile of short-term bosentan therapy looks promising for the treatment of patients with chronic
heart failure
appropriate trials will have to be performed to document clinical benefit during long-term therapy. Finally, the question remains open whether mixed endothelin-1 receptor antagonists like bosentan will have similar effects as compared to antagonists which block the ET(A) receptor only.
...
PMID:Hemodynamic effects of bosentan in patients with chronic heart failure. 1144 7
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