Atrial natriuretic peptide vascular receptor: regulation of low-affinity binding by calcium

1989 ◽  
Vol 76 (1) ◽  
pp. 9-11 ◽  
Author(s):  
J. J. Morton ◽  
Elisabeth C. Beattie ◽  
Fiona Lyall

1. In the presence of calcium, both high- [dissociation equilibrium constant (Kd) 5.8 × 10−11 mol/l] and low-(Kd 1.2 × 10−8 mol/l) affinity binding of atrial natriuretic peptide was detected on plasma membranes prepared from sodium-depleted rats. 2. In contrast, under calcium-free conditions only high-affinity binding (Kd 6.9 × 10−11 mol/l) was detected. 3. The requirement for calcium for low-affinity binding suggests a different mechanism of action than that for the high-affinity receptor.

1990 ◽  
Vol 126 (2) ◽  
pp. 341-347 ◽  
Author(s):  
J. McQueen ◽  
J. C. P. Kingdom ◽  
A. G. Jardine ◽  
J. M. C. Connell ◽  
M. J. Whittle

ABSTRACT Receptors for angiotensin II (AII) and atrial natriuretic peptide (ANP) were characterized in a membrane fraction from resistance-type artery from human placentae. Placentae from normal pregnancies and pregnancies complicated by intrauterine growth retardation (IUGR) were studied. High- and low-affinity receptors for AII (dissociation equilibrium constant (Kd) 1 ·7 and 15·7 nmol/l respectively) and ANP (Kd 0·2 and 55·5 nmol/l respectively) were identified; these parameters were unchanged in IUGR, but there was a reduction in high-affinity receptor number by approximately 50% for AII and 80% for ANP in this condition. Both peptides may have a role in the regulation of fetoplacental blood flow. The alterations in IUGR are consistent with sustained activation of the fetal reninangiotensin system and suggest altered vascular responsiveness to ANP. Journal of Endocrinology (1990) 126, 341–347


1987 ◽  
Vol 73 (6) ◽  
pp. 573-579 ◽  
Author(s):  
Fiona Lyall ◽  
J. J. Morton

1. High-dissociation equilibrium constant (20 pmol/l, receptor number 17 fmol/mg) and low-dissociation equilibrium constant (10 nmol/l, receptor number 5 nmol/mg) affinity binding sites for atrial natriuretic peptide have been identified in membrane preparations from rat mesenteric artery. 2. Tracer degradation was corrected for mathematically and binding data were analysed by a non-linear computer technique. 3. Non-atrial natriuretic peptide vasoactive hormones, angiotensin II, vasopressin and bradykinin, did not compete for the high-affinity site. Related peptides with either C- or N-terminal amino acids missing still competed, while peptides without an intact disulphide bridge did not compete. 4. Neither the addition nor the removal of calcium affected the affinity or density of binding sites. Also the non-hydrolysable guanosine triphosphate analogue 5-guanylylimidodiphosphate had no effect on either affinity or number of sites. 5. These results indicate the presence of a specific high-affinity vascular receptor for atrial natriuretic peptide which could interact with the hormone under physiological conditions. The mechanism of binding is uncertain but is unlikely to involve calcium- or guanosine triphosphate-associated regulatory sites.


1987 ◽  
Vol 5 (4) ◽  
pp. 475???480 ◽  
Author(s):  
James J. Morton ◽  
Fiona Lyall ◽  
Elisabeth C.H. Wallace

1989 ◽  
Vol 37 (11) ◽  
pp. 1739-1742 ◽  
Author(s):  
S Kawaguchi ◽  
K Uchida ◽  
T Ito ◽  
M Kozuka ◽  
M Shimonaka ◽  
...  

Receptors for atrial natriuretic peptide (ANP) were localized in the alveoli and bronchiolar smooth muscle cells of bovine lung and in podocytes of the kidney by immunofluorescence and immunoperoxidase methods. Two specific antisera were raised against the ANP receptor purified from bovine lung plasma membranes: anti-Rc 140 and anti-Rc 70. Anti-Rc 140 was raised against the 140 KD native receptor having a homodimeric structure, and anti-Rc 70 was elicited by immunizing a rabbit with the 70 KD reduced subunits. Essentially identical staining patterns were obtained with both antisera. Identification of ANP receptor sites would provide useful information in understanding the pulmonary and renal actions of ANP.


2009 ◽  
Vol 201 (2) ◽  
pp. 287-295 ◽  
Author(s):  
Shunbun Kita ◽  
Hitoshi Nishizawa ◽  
Yosuke Okuno ◽  
Masaki Tanaka ◽  
Atsutaka Yasui ◽  
...  

Musclin is a novel skeletal muscle-derived secretory factor that was isolated by our group. Musclin contains a region homologous to natriuretic peptides (NPs). This study investigated the interaction between musclin and NP receptors (NPRs). Musclin specifically bound to NPR3, but not to NPR1 or NPR2. Musclin and atrial natriuretic peptide (ANP) competed for binding to NPR3. We conducted binding assays using various synthetic musclin peptides and mutant musclin proteins. The first NP-homologous region in musclin (88LDRL91) and the second homologous region (117MDRI120) were responsible cooperatively for high-affinity binding to NPR3. The first NP-homologous region was more importantly associated with binding to NPR3, than the second homologous region. The competitive nature of musclin with ANP for the natriuretic clearance receptor NPR3 was also confirmed in vivo. We conclude that musclin binds to NPR3 competitively with ANP and may affect ANP concentrations in a local or systemic manner.


1992 ◽  
Vol 70 (8) ◽  
pp. 1167-1174 ◽  
Author(s):  
Peter Cernacek ◽  
Louis Legault ◽  
Duncan J. Stewart ◽  
Mortimer Levy

The diverse biological actions of endothelins (ET) appear to be mediated by specific cell-surface receptors. Autoradiography and membrane binding studies have shown abundant ET binding sites in the kidney. However, their expression in specific types of renal cells is unclear. We studied the binding of 125I-labelled endothelin-1 in freshly isolated cell suspensions from canine inner medullary collecting duct. Competition binding experiments revealed the presence of specific high-affinity binding sites: unlabelled ET-1 and ET-2 competed with the radioligand with an IC50 of 135 and 83 pM, respectively, while the IC50 of ET-3 and big ET-1 were 2 and 4 orders of magnitude higher, indicating the presence of ETA-type receptor. Angiotensin II, vasopressin, and atrial natriuretic peptide (ANP) did not compete for ET binding even at a concentration of 10−6 M. Saturation binding experiments showed a single class of binding sites of high density (Bmax = 56.7 ± 10.3 fmol/106 cells) and high affinity (Kd = 69.8 ± 10 pM). In contrast, ANP receptors in the same cell preparations appeared as two classes of binding sites with widely different affinity and density. The high-affinity ANP site (Kd = 311 ± 48 pM) was compatible with ANP-B (guanylate cyclase-coupled) receptor. ET-1 did not compete for this receptor. ET-1 (10−7 M) did not alter ANP-induced cGMP generation in these cells (3.8-fold increase at 10−7 M ANP), nor basal levels of cGMP. The expression by the distal tubular epithelium of specific ET-1 binding sites strongly suggests the presence of a functional receptor, which may mediate the inhibition of Na+ transport in these cells. The mechanism and the transduction pathway of this effect appear to be different and independent from those of ANP.Key words: endothelin receptor, distal collecting duct, atrial natriuretic peptide receptor, cGMP generation.


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