Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Natriuretic peptides family consists of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP), while receptors for these natriuretic peptides comprise at least three subtypes, i.e. A-type (GC-A), B-type (GC-B) and C-type (clearance). ANP and BNP are cardiac hormones mainly synthesized and secreted by atria and ventricles, respectively, but CNP is a neuropeptide synthesized by brain. Both A- and B-type receptors contain particulate guanylate cyclase within their molecule and mediate biological function via cyclic GMP as a second messenger, whereas C-type receptor is involved in clearance and metabolism of natriuretic peptides. In heart failure, cardiac expression of both ANP and BNP is augmented with increased circulating levels as a cardiac compensatory mechanism. Pathophysiological significance of natriuretic peptides system in heart failure is discussed.
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PMID:[Natriuretic peptide family]. 839 34

Atrial natriuretic factor (ANF) promotes natriuresis and diuresis, increases vascular permeability and may induce peripheral vasodilatation. Endothelium-derived relaxing factor (EDRF), which is nitric oxide (NO), promotes local vasodilatation. ANF and EDRF-NO both cause vascular relaxation by generating cGMP via the activation of the particulate and soluble guanylate cyclases, respectively. This study examines the in vivo effect of exogenous ANF administration in normal Wistar rats, and of increased endogenous ANF in an experimental model of heart failure, on plasma and tissue cGMP concentrations. Low-dose ANF increased plasma and pulmonary cGMP concentrations, whereas 10-fold higher doses were necessary to increase aorta cGMP concentrations. Rats with a myocardial infarction had increased plasma ANF and cGMP and pulmonary cGMP concentrations, but aorta cGMP concentration remained similar to that of sham-operated rats. NG nitro L-arginine methyl ester (L-NAME) was administered chronically to sham-operated and myocardial infarction rats to block NO-synthase: soluble guanylate cyclase activity. L-NAME did not lower the increase in plasma ANF concentration or in urinary, plasma or pulmonary cGMP concentration. In contrast, L-NAME reduced the aorta cGMP concentration 6-fold, despite an increased level of circulating ANF. In summary, the pathophysiological range of plasma ANF concentrations greatly increases plasma and pulmonary cGMP concentrations (by activating particulate guanylate cyclase), but has little influence on the aorta cGMP concentration (which remains mainly dependent on NO-synthase: soluble guanylate cyclase activity).
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PMID:Atrial natriuretic factor influences in vivo plasma, lung and aortic wall cGMP concentrations differently. 839 39

Atrial natriuretic peptide (ANP) and Brain natriuretic peptide (BNP) are cardiac hormones with similar actions and potency in humans yet with distinctly different effects on plasma cyclic guanosine monophosphate (cGMP). Because most biological actions of natriuretic peptides are thought to be mediated by the guanylate cyclase (G-C) receptors via cGMP, we have compared the biological and G-C-stimulating effects of equimolar infusions of ANP and BNP (2 pmol/kg.min), or vehicle control, on renal, hormonal and hemodynamic function in 8 normal subjects. In addition, the modulating effects of ANP and BNP on the biological actions of infused angiotension II (AngII) were studied. During ANP infusions, plasma ANP concentration increased from 8.8 +/- 0.7 pmol/L to 34 +/- 3 pmol/L at 120 min. Similar increments in plasma BNP occurred during BNP infusions (7.3 +/- 0.6 pmol/L preinfusion, 37 +/- 1 pmol/L at 120 min). Increase in plasma cGMP during ANP infusions was 4-fold that observed during BNP infusions yet natriuresis, contraction in plasma volume, and inhibition of plasma aldosterone were comparable. By contrast, ANP (but not BNP) significantly inhibited the plasma aldosterone response to AngII (P < 0.001). The pressor response to AngII was unaltered by ANP or BNP. Thus, at plasma ANP/BNP levels observed in mild heart failure, ANP is more potent than BNP in inhibiting the aldosterone response to AngII. Comparable natriuresis and inhibition of basal aldosterone is seen, despite much less stimulation of plasma cGMP by BNP, suggesting a different mechanism of hormone action-possibly via non-G-C receptor pathways.
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PMID:Differing biological effects of equimolar atrial and brain natriuretic peptide infusions in normal man. 892 31

Natriuretic peptide system consists of three endogenous ligands, ANP (atrial natriuretic peptide), BNP (brain natriuretic peptide) and CNP (C-type natriuretic peptide), and three receptor subtypes, natriuretic peptide receptor (NPR)-A or guanylate cyclase (GC)-A and NPR-B or GC-B and C receptor (NPR-C). ANP and BNP are mainly secreted from the atrium and ventricle of the heart respectively to act as cardiac hormones whereas CNP is secreted from the endothelium to act as an endothelium-derived relaxing peptide. ANP and BNP regulate body fluid and blood pressure to reduce cardiac pre- and after-load. Recent molecular biology and developmental biotechnology demonstrated the physiological role of ANP and BNP for the determination of basal blood pressure. CNP can modulate the phenotype of vascular smooth muscle cells to regulate vascular remodeling. Therefore, natriuretic peptide system is implicated in the pathophysiology of hypertension, congestive heart failure atherosclerosis and renal diseases. Clinical application of natriuretic peptide system is actively going on progress. Determination of plasma ANP and BNP levels are useful for the evaluation of congestive heart failure, cardiac hypertrophy and acute myocardial infarction. Infusion of ANP improves acute heart failure. Application of NEP (neutral endopeptidase) inhibitor for the treatment of congestive heart failure and hypertension is under clinical trial.
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PMID:[Natriuretic peptide system]. 928 3

The physiologic and pathophysiologic importance of natriuretic peptides (NP) has been imperfectly defined. The diminished renal responses to exogenous atrial NP in heart failure have led to the perception that the endogenous NP system might be less effective and thus contribute to renal sodium retention in heart failure. This study tests the hypothesis that in experimental heart failure, the renal responses to an acute volume load are still dependent on the NP system. The specific antagonist HS-142-1 was used to block the effects of NP in a model of high-output heart failure induced by an aortocaval shunt. Plasma cGMP levels and renal cGMP excretion were significantly lower in shunted and sham-operated rats receiving HS-142-1, compared with vehicle-treated controls, indicating effective blockade of guanylate cyclase-coupled receptors. Baseline sodium excretion and urine flow rate were lower in HS-142-1-treated sham-operated rats (15.2+/-1.1 microl/min versus 27.5+/-3.1 microl/min with vehicle, P < 0.001) and in HS-142-1-treated shunted rats (8.1+/-1.3 microl/min versus 19.9+/-2.3 microl/min with vehicle, P < 0.001). After an acute volume load, the diuretic and natriuretic responses were attenuated by HS-142-1 in control and shunted rats. The renal responses were reduced by HS-142-1 to a significantly greater extent in shunted rats than in control rats. HS-142-1 did not induce any significant systemic hemodynamic changes in either group, nor did it alter renal blood flow. However, the GFR in HS-142-1-treated shunted rats was lower than that in vehicle-treated shunted rats, both at baseline (0.6+/-0.3 ml/min versus 2.1+/-0.4 ml/min with vehicle, P < 0.05) and after an acute volume load (1.2+/-0.4 ml/min versus 2.6+/-0.4 ml/min with vehicle, P = 0.01), whereas no such effect was observed in control rats. These data indicate that the maintenance of basal renal function and the responses to acute volume loading are dependent on the NP system. The NP seem to be of particular importance for the maintenance of GFR in this model of experimental heart failure. These observations provide new insights into the importance of the renal NP system in heart failure.
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PMID:Renal function in high-output heart failure in rats: role of endogenous natriuretic peptides. 1007 8

The effects of exogenous and endogenous. NO on myocardial functions such as contraction, relaxation and heart rate have recently gained considerable scientific interest. .NO stimulates myocardial soluble guanylate cyclase to produce cGMP, which activates two major target proteins. A small increase in cGMP levels predominantly inhibits phosphodiesterase III, while high cGMP levels activate cGMP-dependent protein kinase. Accordingly, submicromolar .NO concentrations improve myocardial contraction, while submillimolar .NO concentrations decrease contractility. The latter action includes direct inhibitory .NO effects on ATP synthesis and voltage-gated calcium channels. Overall, the inotropic effects of exogenous .NO are small and probably of minor importance for myocardial contractility. Cardiomyocytes are capable of expressing eNOS and iNOS. Endogenous .NO has effects on myocardial contraction, similar to that of exogenous .NO. Various NOS inhibitors can substantially reduce myocardial contractility in vitro and in vivo, suggesting that basal endogenous .NO production supports myocardial contractility. There is also evidence for a .NO-dependent cardiodepressive effect of cytokines that is mediated by expression of iNOS. This is consistent with the negative inotropic effects of .NO at high concentrations. Cardiodepressive actions of endogenous .NO production may play a role in certain forms of heart failure. Finally, .NO also has an effect on heart rate. Physiologic .NO concentrations can stimulate heart rate by activating the hyperpolarization-activated inward current (If) and this effect decreases at submillimolar .NO concentrations. In summary, physiological concentrations of .NO increase contractility and heart rate under basal conditions, while high .NO concentrations induce the opposite effects.
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PMID:Regulation of basal myocardial function by NO. 1061 6

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.
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PMID:[Functional compartmentation of the endocrine action of cardiac natriuretic peptides]. 1079 May 90

Adrenomedullin (ADM) is a vasodilator produced by vascular endothelium and smooth muscle cells. Although plasma ADM levels are increased in patients with hypertension, heart failure, and myocardial infarction, little information exists regarding the microvascular response to ADM in the human heart. In the present study we tested the hypothesis that ADM produces coronary arteriolar dilation in humans and examined the mechanism of this dilation. Human coronary arterioles were dissected and cannulated with micropipettes. Internal diameter was measured by video microscopy. In vessels constricted with ACh, the diameter response to cumulative doses of ADM (10(-12)-10(-7) M) was measured in the presence and absence of human ADM-(22-52), calcitonin gene-related peptide-(8-37), N(omega)-nitro-L-arginine methyl ester (L-NAME), indomethacin (Indo), (1)H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one, SQ-22536, or KCl (60 mM). ADM dilated human coronary arterioles through specific ADM receptors (maximum dilation = 69 +/- 11%). L-NAME or N-monomethyl-L-arginine attenuated dilation to ADM (for L-NAME, maximum dilation = 66 +/- 7 vs. 41 +/- 13%, P < 0.05). Thus the mechanism of ADM-induced dilation involves generation of nitric oxide. However, neither (1)H-[1,2,4]oxadiazolo-[4, 3-a]quinoxalin-1-one, SQ-22536, nor Indo alone altered dilation to ADM. High concentrations of KCl blocked dilation to ADM. The magnitude of ADM dilation was reduced in subjects with hypertension. We propose that, in human coronary arterioles, ADM elicits vasodilation in part through production of nitric oxide and in part through activation of K(+) channels, with little contribution from adenylyl cyclase. The former dilator mechanism is independent of the more traditional pathway involving activation of soluble guanylate cyclase.
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PMID:Human coronary arteriolar dilation to adrenomedullin: role of nitric oxide and K(+) channels. 1108 13

Atrial myocytes synthesise atrial natriuretic factor prohormone consisting of 126 amino acids (ANP1-126) which is subsequently processed to several fragments. Atrial natriuretic factor (ANF, ANP99-126) originating from the C-terminal portion of prohormone is a best described atrial peptide. However, several peptides originating from the N-terminus of this precursor also circulate and produce significant diuresis, natriuresis and vasodilatation. These are: long acting natriuretic peptide (ANP1-30), vessel dilator (ANP31-67) and kaliuretic peptide (ANP79-98). ANP1-98 and ANP68-98 also circulate. Kaliuretic peptide specifically stimulates urinary potassium excretion. These peptides are slowly metabolised and their plasma concentration is higher than ANF suggesting their important role in water-electrolyte homeostasis and regulation of vascular tone. N-terminal atrial peptides don't bind to classical natriuretic peptide receptors, each of them has probably its own unique receptors. Although these peptides activate particulate guanylate cyclase in a number of tissues, some of their effects, for example natriuresis, are not mediated by cGMP but rather by prostaglandin E2. Plasma concentration of N-terminal atrial peptides may be useful in diagnosis and risk stratification in patients with heart failure and after myocardial infarction. Recently N-terminal fragment of brain natriuretic peptide (BNP1-76) was identified in the blood. This peptide is secreted together with its C-terminal partner, BNP77-108 by ventricular myocytes. Some studies suggest that N-terminal BNP may be also a useful diagnostic tool in cardiovascular diseases.
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PMID:[N-terminal atrial natriuretic peptides]. 1122 84

Guanylin and uroguanylin are short peptides homologous to heat-stable enterotoxins of Escherichia coli and other enteric bacteria. Guanylin and uroguanylin are synthetized from the respective prepropeptides mainly in gastrointestinal mucosa and are secreted both into intestinal lumen and into the blood. Luminally secreted peptides stimulate chloride and bicarbonate secretion in the intestine through the mechanism involving guanylate cyclase C receptor, cyclic GMP, protein kinase G and cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel. Bacterial enterotoxins, which have greater potency than endogenous peptides, induce excessive fluid secretion into intestinal lumen leading to secretory diarhea. Uroguanylin is expressed mainly in enterochromaffin cells of duodenum and proximal small intestine whereas guanylin is abundant in goblet cells of colonic epithelium. Uroguanylin and guanylin increase urinary sodium and potassium excretion both as circulating hormones and as paracrine mediators produced within the kidney. Uroguanylin functions as "intestinal natriuretic hormone" which is secreted in response to oral sodium loading and maintains sodium balance during postprandial period. Plasma and urinary concentrations of guanylin and uroguanylin increase in renal failure and heart failure. Guanylin peptides possess antiproliferative activity in intestinal cells culture and their expression decreases in colonic carcinoma indicating that their deficiency may contribute to the pathogenesis of this disease.
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PMID:Guanylin and related peptides. 1159 56


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