Apparent B-type natriuretic peptide selectivity in the kidney due to differential processing

2001 ◽  
Vol 79 (8) ◽  
pp. 715-722 ◽  
Author(s):  
Ichiro Kishimoto ◽  
F Kent Hamra ◽  
David L Garbers
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Guanylyl Cyclase ◽  
Spectroscopic Analysis ◽  
Cultured Cells ◽  
Neutral Endopeptidase ◽  
Differential Processing ◽  
Primary Means ◽  
Specific Degradation ◽  
Atrial Natriuretic

Two natriuretic peptides, atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP), are found principally in the heart. In preliminary experiments with mouse kidney cells or slices, we found mouse BNP1-45 much more potent than ANP1-28 in causing elevations of cGMP (>50-fold). The guanylyl cyclase-A (GC-A) receptor has been suggested to represent the primary means by which both peptides signal. In cultured cells overexpressing GC-A, BNP and ANP were almost equivalent in potency, suggesting that a receptor unique for BNP exists in the kidney. However, in mice lacking the GC-A gene, neither BNP nor ANP significantly elevated cGMP in kidney slices. Phosphoramidon, a neutral endopeptidase inhibitor, shifted the apparent potency of ANP to values equivalent to that of BNP, suggesting these kidney cell/slices rapidly degrade ANP but not BNP. Mass spectroscopic analysis confirmed that ANP is rapidly cleaved at the first cysteine of the disulfide ring, whereas BNP is particularly stable to such cleavage. Other tissues (heart, aorta) failed to significantly degrade ANP or BNP, and therefore the kidney-specific degradation of ANP provides a mechanism for preferential regulation of kidney function by BNP independent of peripheral ANP concentration.Key words: guanylyl cyclase-A, atrial natriuretic peptide, B-type natriuretic peptide, neutral endopeptidase.

scholarly journals Prolonged Atrial Natriuretic Peptide Exposure Stimulates Guanylyl Cyclase-A Degradation

Endocrinology ◽  
2010 ◽  
Vol 151 (6) ◽  
pp. 2769-2776 ◽  
Author(s):  
Darcy R. Flora ◽  
Lincoln R. Potter
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Guanylyl Cyclase ◽  
Cultured Cells ◽  
Volume Overload ◽  
Receptor Expression ◽  
Dependent Manner ◽  
Down Regulation ◽  
Time Required ◽  
Atrial Natriuretic

Natriuretic peptide receptor-A (NPR-A), also known as guanylyl cyclase-A, is a transmembrane receptor guanylyl cyclase that is activated by the cardiac hormones atrial natriuretic peptide and B-type natriuretic peptide. Although ligand-dependent NPR-A degradation (also known as down-regulation) is widely acknowledged in human and animal models of volume overload, down-regulation in cultured cells is controversial. Here, we examined the effect of ANP exposure on cellular NPR-A levels as a function of time. Relative receptor concentrations were estimated using guanylyl cyclase and immunoblot assays in a wide variety of cell lines that endogenously or exogenously expressed low or high numbers of receptors. ANP exposures of 1 h markedly reduced hormone-dependent but not detergent-dependent guanylyl cyclase activities in membranes from exposed cells. However, 1-h ANP exposures did not significantly reduce NPR-A concentrations in any cell line. In contrast, exposures of greater than 1 h reduced receptor concentrations in a time-dependent manner. The time required for half of the receptors to be degraded (t1/2) in primary bovine aortic endothelial and immortalized HeLa cells was approximately 8 h. In contrast, a 24-h exposure of ANP to 293T cells stably overexpressing NPR-A caused less than half of the receptors to be degraded. To our knowledge, this is the first report to directly measure NPR-A down-regulation in endogenously expressing cells. We conclude that down-regulation is a universal property of NPR-A but is relatively slow and varies with receptor expression levels and cell type.

scholarly journals Atrial natriuretic peptide induces acrosomal exocytosis of human spermatozoa

1998 ◽  
Vol 274 (2) ◽  
pp. E218-E223 ◽  
Author(s):  
Ronit Rotem ◽  
Nadav Zamir ◽  
Nurit Keynan ◽  
Dalit Barkan ◽  
Haim Breitbart ◽  
...  
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Guanylyl Cyclase ◽  
Acrosome Reaction ◽  
Human Spermatozoa ◽  
Subsequent Formation ◽  
Acrosomal Exocytosis ◽  
Cgmp Analog ◽  
Gf 109203X ◽  
Atrial Natriuretic

Acrosomal exocytosis in mammalian spermatozoa is a process essential for fertilization. We report here that atrial natriuretic peptide (ANP) markedly stimulates acrosomal exocytosis of capacitated human spermatozoa. Typically, ANP exerts some of its actions via activation of the ANP receptor (ANPR-A), a particulate guanylyl cyclase-linked receptor, and subsequent formation of guanosine 3′,5′-cyclic monophosphate (cGMP). We found that ANP-stimulated acrosome reaction was inhibited by the competitive ANPR-A antagonist anantin, indicating a receptor-mediated process. A linear fragment of ANP, ANP-(13—28), and another ANP-like compound, brain natriuretic peptide, were inactive. The stimulatory effect of ANP on acrosome reaction was mimicked by the permeable cGMP analog, 8-bromo-cGMP (8-BrcGMP). Addition of the protein kinase C (PKC) inhibitors, staurosporine and GF-109203X, resulted in a dose-related inhibition of ANP-induced acrosome reaction. Also, downregulation of endogeneous PKC activity resulted in inhibition of ANP- but not 8-BrcGMP-induced acrosome reaction. Removal of extracellular Ca2+ abolished ANP-induced acrosome reaction. Thus ANP via Ca2+ influx, PKC activation, and stimulation of particulate guanylyl cyclase may play a role in the induction of acrosome reaction of human spermatozoa.

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.

scholarly journals A cardiac pathway of cyclic GMP-independent signaling of guanylyl cyclase A, the receptor for atrial natriuretic peptide

2011 ◽  
Vol 108 (45) ◽  
pp. 18500-18505 ◽  
Author(s):  
M. Klaiber ◽  
B. Dankworth ◽  
M. Kruse ◽  
M. Hartmann ◽  
V. O. Nikolaev ◽  
...  
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Cyclic Gmp ◽  
Guanylyl Cyclase ◽  
Atrial Natriuretic
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