Neutral Endopeptidase Inhibition: Augmented Atrial and Brain Natriuretic Peptide, Haemodynamic and Natriuretic Responses in Ovine Heart Failure

1996 ◽  
Vol 91 (3) ◽  
pp. 283-291 ◽  
Author(s):  
Miriam Tessa Rademaker ◽  
Christopher John Charles ◽  
Eric Arnold Espiner ◽  
Michael Gary Nicholls ◽  
Arthur Mark Richards ◽  
...  
Keyword(s):  
Heart Failure ◽  
Atrial Natriuretic Peptide ◽  
Brain Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Fold Increase ◽  
Neutral Endopeptidase ◽  
Haemodynamic Effects ◽  
Similar Extent ◽  
Endopeptidase 24.11 ◽  
Atrial Natriuretic

1. Atrial and brain natriuretic peptide are both circulating hormones subject to degradation by neutral endopeptidase 24.11. Whereas endogenous levels of atrial natriuretic peptide are increased by neutral endopeptidase inhibition in most pathophysiological states, the effect on brain natriuretic peptide and the influence of cardiac status is less clear. To further evaluate the role of neutral endopeptidase 24.11, we directly compared the responses of atrial and brain natriuretic peptide, together with the effects on other vasoactive hormones, haemodynamics and renal indices, to a neutral endopeptidase inhibitor, SCH32615, and a vehicle control in eight conscious sheep before and during pacing-induced heart failure. 2. In normal animals, SCH32615 significantly increased concentrations of plasma atrial natriuretic peptide (22±5 pmol/l compared with 14±2 pmol/l in control, 1.6-fold increase) and brain natriuretic peptide (6.5±1.2 pmol/l compared with 4.1±0.7 pmol/l in control, 1.6-fold increase), whereas in heart failure, plasma levels of atrial natriuretic peptide (306±38 pmol/l compared with 187±25 pmol/l in control, 1.6-fold increase) and brain natriuretic peptide (93±11 pmol/l compared with 55 ± 9 pmol/l in control, 1.7-fold increase) were elevated to a significantly greater absolute, but proportionately similar, extent. In both normal and heart-failed animals, SCH32615 induced reductions in mean arterial pressure and left atrial pressure and increases in haematocrit, plasma cGMP and endogenous creatinine clearance. However, only in heart failure did neutral endopeptidase inhibition induce a significant and marked natriuresis (> 10-fold increase) and diuresis (4-fold increase), together with suppression of renin activity and haemodynamic effects including decreased peripheral resistance and raised cardiac output. 3. In conclusion, neutral endopeptidase inhibition increases plasma concentrations of atrial and brain natriuretic peptide to a proportionately similar extent in both normal and heart-failed sheep. The striking natriuresis and diuresis and additional haemodynamic effects demonstrated in sheep with heart failure, where natriuretic peptide levels are elevated compared with normal sheep, supports the concept that neutral endopeptidase inhibition augments endogenous atrial and brain natriuretic peptide.

Clearance of brain natriuretic peptide in patients with chronic heart failure: indirect evidence for a neutral endopeptidase mechanism but against an atrial natriuretic peptide clearance receptor mechanism

1992 ◽  
Vol 82 (6) ◽  
pp. 619-623 ◽  
Author(s):  
Chim C. Lang ◽  
Joseph G. Motwani ◽  
Wendy J. R. Coutie ◽  
Allan D. Struthers
Keyword(s):  
Heart Failure ◽  
Chronic Heart Failure ◽  
Atrial Natriuretic Peptide ◽  
Human Brain ◽  
Brain Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Neutral Endopeptidase ◽  
Striking Similarity ◽  
Plasma Atrial Natriuretic Peptide ◽  
Atrial Natriuretic

1. Brain natriuretic peptide is a new natriuretic hormone with striking similarity to atrial natriuretic peptide, but there are no previous data concerning its clearance in man. Two pathways of clearance for atrial natriuretic peptide are recognized: degradation by neutral endopeptidase and binding to atrial natriuretic peptide clearance receptors. We have examined the effect of candoxatril, an inhibitor of neutral endopeptidase (dose range 10–200 mg), and the effect of an infusion of a pharmacological dose [45 μg (90 μg in two patients)] of synthetic human atrial natriuretic peptide on plasma human brain natriuretic peptide-like immunoreactivity levels in seven patients with mild to moderate chronic heart failure. 2. Plasma human brain natriuretic peptide-like immunoreactivity levels were elevated in all patients (mean ± sem 22.0 ± 6.2 pmol/l) compared with healthy control subjects (1.3 ± 0.2 pmol/l, n = 11). 3. In all patients, candoxatril increased both plasma atrial natriuretic peptide (P < 0.05) and plasma human brain natriuretic peptide-like immunoreactivity (P < 0.05) levels. 4. By contrast, an exogenous infusion of atrial natriuretic peptide had no effect on plasma human brain natriuretic peptide-like immunoreactivity levels despite increasing the plasma atrial natriuretic peptide concentration to 424 ± 74 pmol/l, which is a level of atrial natriuretic peptide which would have ‘swamped’ all atrial natriuretic peptide clearance receptors. 5. We have therefore shown that plasma human brain natriuretic peptide-like immunoreactivity levels in chronic heart failure are increased by a neutral endopeptidase inhibitor, but are unchanged by an exogenous infusion of atrial natriuretic peptide. Our results suggest that in patients with chronic heart failure, degradation by neutral endopeptidase is an important pathway for clearance of brain natriuretic peptide. By an indirect approach, we did not find any evidence of a role for atrial natriuretic peptide clearance receptors in the metabolism of brain natriuretic peptide in these patients. Although this is in agreement with work in vitro, there could be alternative explanations for the lack of a change in circulating human brain natriuretic peptide-like immunoreactivity during exogenous administration of atrial natriuretic peptide.

scholarly journals Evaluation of Atrial Natriuretic Peptide and Brain Natriuretic Peptide in Atrial Granules of Rats with Experimental Congestive Heart Failure

2001 ◽  
Vol 49 (10) ◽  
pp. 1293-1300 ◽  
Author(s):  
Gad M. Bialik ◽  
Zaid A. Abassi ◽  
Ilan Hammel ◽  
Joseph Winaver ◽  
Dina Lewinson
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Atrial Natriuretic Peptide ◽  
Brain Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Aortocaval Fistula ◽  
Granule Formation ◽  
Gold Particles ◽  
The Mean ◽  
Atrial Natriuretic

The natriuretic peptides are believed to play an important role in the pathophysiology of congestive heart failure (CHF). We utilized a quantitative cytomorphometric method, using double immunocytochemical labeling, to assess the characteristics of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in atrial granules in an experimental model of rats with CHF induced by aortocaval fistula. Rats with CHF were further divided into decompensated (sodium-retaining) and compensated (sodium-excreting) subgroups and compared with a sham-operated control group. A total of 947 granules in myocytes in the right atrium were analyzed, using electron microscopy and a computerized analysis system. Decompensated CHF was associated with alterations in the modal nature of granule content packing, as depicted by moving bin analysis, and in the granule density of both peptides. In control rats, the mean density of gold particles attached to both peptides was 347.0 ± 103.6 and 306.3 ± 89.9 gold particles/μm2 for ANP and BNP, respectively. Similar mean density was revealed in the compensated rats (390.6 ± 81.0 and 351.3 ± 62.1 gold particles/μm2 for ANP and BNP, respectively). However, in rats with decompensated CHF, a significant decrease in the mean density of gold particles was observed (141.6 ± 67.3 and 158.0 ± 71.2 gold particles/μm2 for ANP and BNP, respectively; p < 0.05 compared with compensated rats, for both ANP and BNP). The ANP:BNP ratio did not differ between groups. These findings indicate that the development of decompensated CHF in rats with aortocaval fistula is associated with a marked decrease in the density of both peptides in atrial granules, as well as in alterations in the quantal nature of granule formation. The data further suggest that both peptides, ANP and BNP, may be regulated in the atrium by a common secretory mechanism in CHF.

Regional plasma levels of cardiac peptides and their response to acute neutral endopeptidase inhibition in man

1998 ◽  
Vol 95 (5) ◽  
pp. 547-555 ◽  
Author(s):  
J. G. LAINCHBURY ◽  
M. G. NICHOLLS ◽  
E. A. ESPINER ◽  
H. IKRAM ◽  
T. G. YANDLE ◽  
...  
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Brain Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Coronary Sinus ◽  
Femoral Artery ◽  
Natriuretic Peptides ◽  
Plasma Levels ◽  
Neutral Endopeptidase ◽  
Brain Natriuretic Peptides ◽  
Atrial Natriuretic

1.The cardiac natriuretic peptides, atrial natriuretic peptide and brain natriuretic peptide, are degraded via clearance receptors and the enzyme neutral endopeptidase (EC 3.4.24.11). We studied the regional plasma concentrations of these peptides and their response to acute neutral endopeptidase inhibition in a consecutive series of patients with a broad spectrum of severity of cardiac dysfunction who were undergoing diagnostic right and left heart catheterization (24 patients, mean age 62.6 years). 2.Baseline blood samples were obtained for hormone analysis from femoral artery, femoral vein, renal vein, hepatic vein, superior vena cava, coronary sinus and pulmonary artery, and initial haemodynamic measurements were made. Twelve patients then received a neutral endopeptidase inhibitor (SCH 32615, 200 ;mg intravenously) and 12 received vehicle alone. The cardiac catheterization procedure was then completed and haemodynamic and hormone measurements were repeated. 3.Haemodynamic status was similar at baseline in both groups, and at repeated measurement (post-procedure after placebo or active drugs) haemodynamic variables were not significantly different from baseline values. Plasma levels of atrial and brain natriuretic peptides exhibited an arteriovenous increment (344% and 124% respectively) across the heart (femoral artery to coronary sinus) and decrement (by 28–54% and 9–16% respectively) across all other tissue beds (P< 0.05 for all) except the lung (no change). Final levels of atrial natriuretic peptide rose above initial levels at all sites in both groups (P< 0.05) except coronary sinus levels in the vehicle group (no change). The increase was consistently greater in the inhibitor group at all sites (P< 0.05 versus placebo). Levels of brain natriuretic peptide rose at all sites in the inhibitor group only (P< 0.05). The transcardiac step-up in atrial natriuretic peptide was markedly augmented after the administration of neutral endopeptidase inhibitor. Other tissue gradients were not significantly altered by neutral endopeptidase inhibitor. 4.Atrial and brain natriuretic peptides in plasma are degraded by a number of tissues, and respond differently to cardiac catheterization. Neutral endopeptidase has a significant role in determining plasma levels of natriuretic peptides, in part perhaps by influencing the amount of intact peptide reaching the circulation after secretion from the heart.

Haemodynamic effects of atrial natriuretic peptide in rats with heart failure

1987 ◽  
Vol 140 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Tuula Tikkanen ◽  
Margareta Svartström-Fraser ◽  
Ilkka Tikkanen ◽  
Hannu Sariola ◽  
Frej Fyhrquist
Keyword(s):  
Heart Failure ◽  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Haemodynamic Effects ◽  
Atrial Natriuretic

Pulsatile secretion of atrial natriuretic peptide and brain natriuretic peptide in healthy humans

1999 ◽  
Vol 97 (2) ◽  
pp. 201-206 ◽  
Author(s):  
Erling B. PEDERSEN ◽  
Henrik B. PEDERSEN ◽  
Kaare T. JENSEN
Keyword(s):  
Heart Failure ◽  
Atrial Natriuretic Peptide ◽  
Brain Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Plasma Concentrations ◽  
Blood Samples ◽  
Pulsatile Secretion ◽  
Healthy Humans ◽  
Severity Of The Disease ◽  
Atrial Natriuretic

Both atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are involved in sodium and water homoeostasis in healthy humans. The plasma concentrations of the natriuretic peptides can be used to differentiate between dyspnoea of cardiac and pulmonary origin, and the degree of elevation of the peptide levels in the plasma in heart failure is a measure of the severity of the disease. However, the patterns of secretion of ANP and BNP are not clear either in healthy humans or in patients. The purpose of the present study was to test the hypotheses that both ANP and BNP are secreted in pulses in healthy humans, and that this phenomenon can be revealed by determination of ANP and BNP in peripheral venous blood samples. In 12 healthy subjects, blood samples were drawn every 2 min through an intravenously inserted plastic needle over a period of 2 h. Plasma concentrations of ANP and BNP were determined by RIAs, and the results were analysed for pulsatile behaviour by Fourier transformation. Pulsatile secretion of ANP was seen in 10 out of 12 subjects [ν = 0.028 min-1 (median; range 0.013–0.047 min-1), i.e. a pulse of ANP with an interval of 36 min (range 21–77 min)]. Pulsatile secretion of BNP was seen in nine out of 12 patients [ν = 0.021 min-1 (range 0.013–0.042 min-1), i.e. a pulse of BNP with an interval of 48 min (range 24–77 min)]. The main conclusion is that the secretion patterns of both ANP and BNP are pulsatile in most healthy humans. Consequently, it is important to study whether pulsatile secretion also occurs in heart failure in order to obtain the most informative predictive values both in the differential diagnosis of dyspnoea and in the evaluation of the severity of the disease.

Elevated Plasma C-Type Natriuretic Peptide Concentrations in Patients with Chronic Renal Failure

1994 ◽  
Vol 87 (3) ◽  
pp. 319-322 ◽  
Author(s):  
Kazuhito Totsune ◽  
Kazuhiro Takahashi ◽  
Osamu Murakami ◽  
Fumitoshi Satoh ◽  
Masahiko Sone ◽  
...  
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Renal Failure ◽  
Chronic Renal Failure ◽  
Atrial Natriuretic Peptide ◽  
Brain Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Heart Association ◽  
Normal Subjects ◽  
Atrial Natriuretic

1. C-type natriuretic peptide is a neuropeptide, which is also produced by the vascular endothelial cells. Plasma immunoreactive C-type natriuretic peptide concentrations in patients with various diseases have not yet been studied. 2. Plasma immunoreactive C-type natriuretic peptide concentrations were studied by radioimmunoassay in normal subjects, patients with congestive heart failure, non-dialysed patients with chronic renal failure and haemodialysis patients with chronic renal failure. The C-type natriuretic peptide levels were compared with the levels of atrial natriuretic peptide and brain natriuretic peptide. 3. Plasma immunoreactive C-type natriuretic peptide concentrations were greatly elevated in patients with chronic renal failure [non-dialysed, 13.0 ± 4.2 pmol/l (mean ± SEM), n = 9, P < 0.01) compared with normal subjects (4.4 ± 0.4 pmol/l, n = 26); haemodialysis, 16.1 ± 2.1 pmol/l, n = 13, P < 0.01], but not in patients with congestive heart failure (New York Heart Association Class II-IV, 3.0 ± 0.7 pmol/l, n = 11, P > 0.05). Plasma immunoreactive atrial natriuretic peptide and brain natriuretic peptide concentrations were elevated both in patients with congestive heart failure and in haemodialysis patients with chronic renal failure. 4. Reverse-phase high performance liquid chromatography showed that immunoreactive C-type natriuretic peptide in plasma from normal subjects and haemodialysis patients was eluted in the positions of C-type natriuretic peptide −22 and −53. 5. These findings suggest that C-type natriuretic peptide is a non-cardiac circulating hormone and participates in the cardiovascular regulation in a different manner from atrial natriuretic peptide and brain natriuretic peptide.

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