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Query: UMLS:C0018801 (
heart failure
)
72,216
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We have recently identified a novel amino-terminal fragment of pro-brain natriuretic peptide (NT-proBNP) in the circulation of humans, the concentration of which increases progressively as the left ventricle fails. To clarify the origins of NT-proBNP in experimental animals, we have developed an RIA for NT-proBNP based on residues 52-71 of ovine proBNP-(1-103) and used it to study cardiac processing, secretion, and metabolism of
BNP
in sheep with cardiac overload induced by coronary artery ligation (CAL) or rapid left ventricular pacing (rLVP). The concentration of NT-proBNP in left atrial plasma extracts drawn from normal control sheep was threefold that of mature
BNP
. Size-exclusion and reverse-phase HPLC analyses of plasma extracts coupled to RIA revealed a single peak of immunoreactive (ir) NT-proBNP [ approximately 8,000 relative molecular weight (Mr)], quite distinct from a single peak of ir-mature
BNP
( approximately 3,000 Mr). In contrast, ovine cardiac tissue contained only a single immunoreactive peak of high-molecular-weight
BNP
( approximately 11,000 Mr), consistent in size with proBNP-(1-103). Sampling from the cardiac coronary sinus in normal control sheep (n = 5) and sheep with CAL (n = 5) revealed that the molar ratio of NT-proBNP to mature
BNP
was similar. There was a significant gradient of both mature and NT-proBNP across the heart in normal sheep, whereas after CAL the gradient was significant for mature
BNP
only. In both forms of cardiac overload (CAL and rLVP), left atrial plasma levels of NT-proBNP were significantly increased above normal levels, in contrast with mature
BNP
levels, which were raised only in the rLVP group of animals. Blockade of natriuretic peptide metabolism in sheep with
heart failure
(induced by rLVP) raised mature
BNP
levels threefold but did not affect levels of NT-proBNP. In conclusion, these studies show that NT-proBNP is formed from proBNP stores during secretion and, compared with mature
BNP
, accumulates in plasma because metabolism of NT-proBNP appears to differ from that of mature
BNP
. Although its function, if any, remains unclear, plasma NT-proBNP may prove to be a sensitive marker of cardiac overload and/or decompensation.
...
PMID:Amino-terminal proBNP in ovine plasma: evidence for enhanced secretion in response to cardiac overload. 974 67
1. Hormones involved in cardiovascular regulation are influenced by drug treatment. It is therefore difficult to study endocrine mechanisms in
heart failure
as most patients are already on treatment by the time they reach hospital. 2. We studied nine hospital in-patients before and after treatment of acute New York Heart Association class IV
heart failure
. 3. Before treatment, plasma brain and atrial natriuretic peptides were markedly elevated (
BNP
121 +/- 26 pg/ml, ANP 163 +/- 33 pg/ml; normal range:
BNP
3.9 +/- 0.3 pg/ml, ANP 8.6 +/- 0.8 pg/ml) and correlated positively with serum creatinine and left ventricular end-diastolic diameter and negatively with ejection fraction. Eight patients improved and one died. 4. With improvement plasma ANP and
BNP
fell. Initial renin activity was within the normal range but increased on treatment. Plasma neuropeptide Y and adrenaline remained normal before and after treatment in the eight patients who improved. Initial plasma noradrenaline was in the normal range in four of these patients and just above normal in a further four. In the patient who died, initial plasma neuropeptide Y and catecholamines were very high. 5. Plasma
BNP
emerged as complementary to ANP as a dynamic index in severe
heart failure
; however, renal function is also an important determinant of plasma
BNP
and ANP. There is little evidence for activation of the circulating renin-angiotensin-aldosterone system or neuropeptide Y before treatment of acute
heart failure
.
...
PMID:How does treatment influence endocrine mechanisms in acute severe heart failure? Effects on cardiac natriuretic peptides, the renin system, neuropeptide Y and catecholamines. 985 56
Vasopeptidase inhibition is a new concept in cardiovascular therapy. It involves simultaneous inhibition with a single molecule of two key enzymes involved in the regulation of cardiovascular function, neutral endopeptidase (EC 24.11; NEP) and angiotensin-converting enzyme (ACE). Simultaneous inhibition of NEP and ACE increases natriuretic and vasodilatory peptides (including atrial natriuretic peptide [ANP], brain natriuretic peptide [
BNP
] of myocardial cell origin, and C-type natriuretic peptide [CNP] of endothelial cell origin) and increases the half-life of other vasodilator peptides including bradykinin and adrenomedullin. By simultaneously inhibiting the renin-angiotensin-aldosterone system and potentiating the natriuretic peptide system, vasopeptidase inhibitors (VPIs) reduce vasoconstriction and enhance vasodilation, thereby decreasing vascular tone and lowering blood pressure. Omapatrilat, a heterocyclic dipeptide mimetic, is a novel vasopeptidase inhibitor and a single molecule that simultaneously inhibits NEP and ACE with similar inhibition constants. Unlike ACE inhibitors, omapatrilat demonstrates antihypertensive efficacy in low-, normal-, and high-renin animal models. Unlike NEP inhibitors, omapatrilat provides a potent and sustained antihypertensive effect in spontaneously hypertensive rats (SHR), a model of human essential hypertension. In animal models of
heart failure
, omapatrilat is more effective than ACE inhibition in improving cardiac performance and ventricular remodeling and prolonging survival. Omapatrilat effectively reduces blood pressure, provides target-organ protection, and reduces morbidity and mortality from cardiovascular events in animal models. Omapatrilat is the first VPI to enter advanced USA clinical trials. Omapatrilat appears to be a safe, well-tolerated and effective antihypertensive in humans. Vasopeptidase inhibition is a novel and efficacious strategy for treating cardiovascular disorders, including hypertension and
heart failure
, that may offer advantages over currently available therapies.
...
PMID:Vasopeptidase inhibition: a new concept in blood pressure management. 1034 Aug 42
Cardiac natriuretic peptides (ANP,
BNP
, and biologically active peptides of the N-terminal proANP1-98) are differently regulated in their production/secretion patterns and clearance rates; consequently, the assay for these peptides may provide complementary (or even different) pathophysiological and/or clinical information. The assay for cardiac natriuretic peptides has been utilized in clinical conditions associated with expanded fluid volume. In particular, this assay can be useful in discriminating between normal subjects and patients in different stages of
heart failure
and can also be considered a prognostic indicator of long-term survival in patients with
heart failure
and/or after acute myocardial infarction. Non-competitive immunometric assays (such as two-site IRMAs), even if more expensive, seem to be preferable to RIAs for routinary assay of cardiac peptide hormones because they generally have a better degree of sensitivity, accuracy, and precision.
...
PMID:Pathophysiologic relevance of measuring the plasma levels of cardiac natriuretic peptide hormones in humans. 1056 49
Clinical
heart failure
, often the result of myocardial infarction, may be preceded by a period of compensated left ventricular impairment. There is substantial need for an experimental model that reflects this human condition. In sheep, coronary artery ligation produced consistent left ventricular anteroapical myocardial infarctions resulting in chronic (5 wk), stable hemodynamic changes compared with sham controls, including reductions in ejection fraction (51 +/- 2 vs. 30 +/- 5%, P < 0.001), cardiac output (6.3 +/- 0.2 vs. 5.1 +/- 0.2 l/min, P < 0.01), and arterial pressure (93 +/- 2 vs. 79 +/- 3 mmHg, P < 0.001), and increases in cardiac preload (left atrial pressure, 3.3 +/- 0.1 vs. 8.3 +/- 1.3 mmHg, P < 0.001). These changes were associated with acute and sustained increases in plasma concentrations of atrial natriuretic peptide (ANP; 5 wk, 11 +/- 2 vs. 27 +/- 5 pmol/l, P < 0.001), brain natriuretic peptide (
BNP
; 3 +/- 0.2 vs. 11 +/- 2 pmol/l, P < 0.001), and amino-terminal pro-brain natriuretic peptide (NT-
BNP
; 17 +/- 3 vs. 42 +/- 12 pmol/l, P < 0.001). Significant correlations were observed between plasma levels of the natriuretic peptides (ANP, day 7 to week 5 samples;
BNP
and NT-
BNP
, day 1 to week 5 samples) and changes in left ventricular volumes and ejection fraction. In contrast, renin activity, aldosterone, catecholamines, and endothelin were not chronically elevated postinfarction and were not related to indexes of ventricular function. Coronary artery ligation in sheep produces the pathological, hemodynamic, and neurohormonal characteristics of compensated left ventricular impairment secondary to myocardial infarction. Plasma concentrations of the cardiac natriuretic peptides are sensitive markers of left ventricular dysfunction. This is a reproducible model that reflects the clinical condition and should prove suitable for investigating the pathophysiology of, and experimental therapies in, early left ventricular dysfunction.
...
PMID:Neurohormones in an ovine model of compensated postinfarction left ventricular dysfunction. 1071 Mar 40
It was well-established that the heart has an endocrine function because it is able to synthesize and secrete a family of related peptide hormones (known as cardiac peptide hormones) with potent diuretic, natriuretic and with complex interactions with the hormonal and nervous systems. Cardiac natriuretic peptides (ANP,
BNP
, and biologically active peptides of the N-terminal proANP1-98) are differently regulated in their production/secretion patterns and clearance rates; consequently, the assay for these peptides may provide complementary (or even different) pathophysiological and/or clinical information. The assay for cardiac natriuretic peptides has been utilized in clinical conditions associated with expanded fluid volume. In particular, this assay can be useful in discriminating between normal subjects and patients in different stages of
heart failure
and can also be considered as a prognostic indicator of long-term survival in patients with
heart failure
and/or after acute myocardial infarction. Non-competitive immunometric assays (such as two-site IRMAs), even if more expensive, seem to be preferable to RIAs for routinary assay of cardiac peptide hormones because they generally have a better degree of sensitivity, accuracy, and precision. The technical characteristics and the potential clinical usefulness of some of the methods for measuring these peptides are reviewed.
...
PMID:[Physiological significance and clinical utility of analytical methods for cardiac natriuretic peptides]. 1073 42
The endocrine function of the heart is to secrete Atrial and Brain natriuretic -peptides (ANP and
BNP
). These peptides are biologically active via particulate guanylate cyclases which generate cyclic GMP, the second intracellular messenger. A polysaccharide antagonist, HS-142-1 has been recently described by a Japanese Group. Cyclic GMP is partly secreted from the target cells into the extra cellular medium in which its accumulation is proportional to the concentration of the natriuretic peptide. Neutral Endopeptidase (NEP) is a zinc ectoenzyme involved in the catabolism of natriuretic peptides. NEP is absent in plasma but present on the surface of endothelial and smooth muscle cells. NEP is mainly expressed at the apical pole of the epithelial cells of the proximal tubule in the nephron. Chronic increase in volume and pressure within the cardiac cavities is associated with the oversecretion of natriuretic peptides. This chronic phenomenon involves the recruitment of all the cardiac myocytes to express natriuretic peptide genes. The clinical application of this hyperplasic phenomenon is congestive heart failure, in which the plasma levels of natriuretic peptides correlate with the level of the -hemodynamic stress. Therefore the plasma levels of natriuretic peptides are good pronostic markers in both experimental and human
heart failure
. The degree of congestive heart failure as well as the plasma levels of ANP and
BNP
are also -correlated with the plasma and urinary levels of cyclic GMP. The plasma level of -cyclic GMP is correlated with the endothelial concentration of cyclic GMP but not with the cyclic GMP concentration in smooth muscle cells. From these experimental data, we can conclude that plasma cyclic GMP originates from endothelial cells and is related to particulate guanylate cyclase activity. In contrast natriuretic peptides do not modulate vascular wall cyclic GMP content. The natriuretic action of ANP is probably due to the interaction of the filtered peptide with the particulate guanylate cyclase at the apical pole of the epithelial cells. The apparition of peptiduria associated with natriuresis during NEP inhibition provides evidence of the action of the peptide in the urinary compartment. It is also by a urinary pathway via the macula densa that ANP, and its potentiation by NEP inhibition, decreases renin secretion. The fact that plasma levels of ANP and plasma and urine levels of cyclic GMP correlate with the degree of salt retention in congestive heart failure, provides evidence for chronic desensitization of the system. An up-regulation of Na(+), K(+), 2Cl(-) expression associated with experimental congestive heart failure has recently been shown. Similarly, a modulation of the different sodium transporter systems along the nephron could be one of the counter-regulations leading to desensitization to natriuretic peptides. In conclusion, natriuretic peptides are true endocrine peptides, secreted by the heart, transported in the plasma, filtered by the glomeruli and active at the nephron level. The molecular effector of ANP and cyclic GMP in the epithelial cells is probably the G-kinase II, isoform phosphorylating the cystic fibrosis transmembrane conductance regulator (CFTR). The exact mechanism of desensitization remains to be elucidated.
...
PMID:[Functional compartmentation of the endocrine action of cardiac natriuretic peptides]. 1079 May 90
To evaluate whether or not beta-blockers can improve the condition of patients with
heart failure
treated with a combination of diuretics, digitalis and angiotensin-converting enzyme inhibitor (ACEI), 52 patients with chronic
heart failure
who have been treated with ACEI for more than 6 months were enrolled. They were divided into 2 groups: 26 patients continued the same therapy another 6 months or more (group A), and 26 patients were given oral metoprolol for 6 months or more, in addition to the ACEI (group B). Echocardiographic parameters and atrial and brain natriuretic peptides (ANP,
BNP
) were measured. The left ventricular dimensions at end-diastole and end-systole were significantly decreased and fractional shortening was significantly increased in group B after 6 months' treatment with the beta-blocker, but these parameters remained unchanged in group A. Plasma levels of both ANP and
BNP
were significantly decreased in group B, but remained unchanged in group A. These results indicate that concomitant beta-blocker therapy can improve left ventricular function and attenuate plasma ANP and
BNP
levels in patients with chronic
heart failure
treated with ACEI.
...
PMID:Effect of beta-blocker on left ventricular function and natriuretic peptides in patients with chronic heart failure treated with angiotensin-converting enzyme inhibitor. 1083 52
The syndrome of chronic
heart failure
(CHF) is usually attributable to left ventricular dysfunction (LVD), which is most commonly systolic in nature. Many patients who go on to develop
heart failure
pass through a phase in which they have significant systolic dysfunction but lack clinical symptoms and signs: so-called asymptomatic LVD (ALVD). Treatment of this asymptomatic phase with angiotensin-converting enzyme inhibitors can delay the progression to CHF and ameliorate its substantial morbidity and mortality. This article reviews the epidemiology of ALVD. ALVD is at least as prevalent as CHF, is mainly caused by ischemic heart disease, significantly impairs effort capacity, reduces quality of life, and is associated with a substantial mortality rate. As such, it would appear to satisfy many of the criteria required to screen for a disease. The natriuretic peptide hormones (atrial natriuretic peptide and brain natriuretic peptide ) are elevated in subjects with ALVD.
BNP
, in particular, has acceptable accuracy to detect LVD in the general population. In particular, it has a high negative predictive value meaning a low concentration makes the presence of significant LVD highly unlikely. As such it has the potential to be a cost-effective means of filtering subjects suspected of having LVD and allowing more appropriate use of tertiary referrals for specialist assessment and detailed echocardiography.
...
PMID:Asymptomatic left ventricular dysfunction in the community. 1098 Sep 16
A-type and B-type natriuretic peptides (ANP and
BNP
) are secreted into the systemic circulation via the coronary sinus. Plasma levels of ANP and
BNP
at the coronary sinus should directly determine the systemic circulating levels. However, the metabolic clearance of these hormones are dependent on similar systems, natriuretic peptide clearance receptor (NPR-C) and neutral endopeptidase 24.11 (NEP), suggesting a possible interaction between ANP and
BNP
on metabolic clearance. In this study, we examined the interaction on metabolic clearance in patients with
heart failure
. We obtained blood samples from the coronary sinus and aortic root in 100 patients with
heart failure
and 28 control subjects. The difference in ANP and
BNP
levels between the coronary sinus and the aortic root is reflected partly by the metabolic clearance in the pulmonary circulation. In this study, we examined the possible interaction on metabolic clearance between ANP and
BNP
using a statistical procedure. The ratio of the level of
BNP
to ANP (
BNP
/ANP) was significantly higher in the aortic root than in the coronary sinus at any stage of
heart failure
. We performed multiple regression analysis using ANP and
BNP
levels at the coronary sinus as independent variables (X1 and X2, respectively) and the ANP level at the aortic root as a dependent variable (Y). The analysis showed that both X1 and X2 were significant variables in the equation. On the other hand, we performed the same analysis using the
BNP
level at the aortic root as a dependent variable (Y). The analysis showed that only X2 was a significant variable in the equation. This study suggests that (1) the metabolic clearance in the pulmonary circulation is higher for ANP versus
BNP
and (2) the amount of ANP cleared in the pulmonary circulation depends on the amount of both ANP and
BNP
secreted from the heart, whereas the amount of
BNP
cleared in the pulmonary circulation is dependent solely on the amount of
BNP
secreted from the heart.
...
PMID:Interaction on metabolic clearance between A-type and B-type natriuretic peptides in patients with heart failure. 1101 10
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