Stoichiometry of the atrial natriuretic factor-R1 receptor complex in the bovine zona glomerulosa

Biochemistry ◽  
1995 ◽  
Vol 34 (7) ◽  
pp. 2130-2136 ◽  
Author(s):  
J.-J. Rondeau ◽  
N. McNicoll ◽  
J. Gagnon ◽  
N. Bouchard ◽  
H. Ong ◽  
...  
Keyword(s):  
Atrial Natriuretic Factor ◽  
Zona Glomerulosa ◽  
Receptor Complex ◽  
Natriuretic Factor ◽  
Atrial Natriuretic

scholarly journals Kinetic analysis of internalization, recycling and redistribution of atrial natriuretic factor-receptor complex in cultured vascular smooth-muscle cells. Ligand-dependent receptor down-regulation

1992 ◽  
Vol 288 (1) ◽  
pp. 55-61 ◽  
Author(s):  
K N Pandey
Keyword(s):  
Smooth Muscle ◽  
Cell Surface ◽  
Atrial Natriuretic Factor ◽  
Dependent Manner ◽  
Receptor Complex ◽  
Down Regulation ◽  
Surface Receptors ◽  
Natriuretic Factor ◽  
Metabolic Degradation ◽  
Atrial Natriuretic

The kinetics of internalization, sequestration and metabolic degradation of atrial natriuretic factor (ANF)-receptor complex were studied in rat thoracic aortic smooth-muscle (RTASM) cells. These parameters were directly determined by measuring 125I-ANF binding to total, intracellular and cell-surface receptors. Pretreatment of cells with the lysosomotropic agent chloroquine and the energy depleter dinitrophenol led to an increase in the intracellular 125I-ANF radioactivity. After 60 min incubation at 37 degrees C, cell-associated 125I-ANF radioactivity fell rapidly in chloroquine-treated cells (> 85%) compared with the controls (< 45%). 125I-ANF radioactivity increased to a peak of 65% of the initial level within 15 min in chloroquine-treated cells compared with only 22% in the control cells. During the initial incubation period at 37 degrees C, chloroquine inhibited the release of both intact and degraded 125I-ANF in a time-dependent manner. However, at later incubation times, the effect of chloroquine was diminished and release of both degraded and intact ligand was resumed. Extracellular unlabelled ANF did not affect the release of degraded 125I-ANF but it accelerated the release of intact ANF by a retroendocytotic mechanism. After the endocytosis, about 30-40% of ANF receptors were restored to the cell surface from the internalized pool of receptors. The restoration was blocked by chloroquine or dinitrophenol but not by cycloheximide. Exposure of RTASM cells to unlabelled ANF resulted in a time- and concentration-dependent loss of ANF receptors. Unlabelled ANF (10 nM) induced a loss of more than 52% of 125I-ANF binding, and a complete loss occurred at micromolar concentrations. It is inferred that ANF-induced down-regulation of its receptor resulted primarily from an increased rate in internalization and metabolic degradation of ligand-receptor complex by receptor-mediated endocytotic mechanisms.

A highly specific radioreceptor assay for the active circulating form of atrial natriuretic factor in human plasma.

1988 ◽  
Vol 34 (11) ◽  
pp. 2275-2279 ◽  
Author(s):  
H Ong ◽  
A De Léan ◽  
C Gagnon
Keyword(s):  
Human Plasma ◽  
Atrial Natriuretic Factor ◽  
Zona Glomerulosa ◽  
Radioreceptor Assay ◽  
Membrane Receptors ◽  
Clinical Samples ◽  
Minimum Detectable Concentration ◽  
Natriuretic Factor ◽  
Detectable Concentration ◽  
Atrial Natriuretic

Abstract This highly sensitive radioreceptor assay (RRA) for the active circulating form of atrial natriuretic factor (ANF), fragment 99-126, in human plasma requires 125I-labeled ANF, bovine zona-glomerulosa membrane receptors, and amiloride HCl. The amiloride elicits an increase in the binding affinity of ANF to its receptors. ANF is extracted from human plasma with "Sep-Pak" cyano cartridges. After a 90-min incubation at 25 degrees C, bound and free fractions are separated by filtration. The ANF concentration that inhibits receptor binding of the radioligand by 50% is 12.4 fmol of unlabeled ANF per tube. The minimum detectable concentration is 0.2 fmol per tube. Using ANF-supplemented plasma samples, there was a good correlation (r = 0.99) between ANF concentrations found and those expected. Only the active circulating form of ANF fully cross-reacts in this assay, which confirms its high selectivity. Results correlated strongly (r = 0.93) for clinical samples tested by RRA and RIA.

scholarly journals Photoaffinity labelling of atrial natriuretic factor (ANF)-R1 receptor by underivatized 125I-ANF. Involvement of lipid peroxidation

1990 ◽  
Vol 267 (2) ◽  
pp. 379-384 ◽  
Author(s):  
L Larose ◽  
N McNicoll ◽  
J J Rondeau ◽  
E Escher ◽  
A De Lean
Keyword(s):  
Lipid Peroxidation ◽  
Atrial Natriuretic Factor ◽  
Guanidine Hydrochloride ◽  
Physiological Effect ◽  
Zona Glomerulosa ◽  
Binding Domain ◽  
Membrane Receptors ◽  
Simple Method ◽  
Natriuretic Factor ◽  
Atrial Natriuretic

In bovine adrenal zona glomerulosa, atrial natriuretic factor (ANF) exerts its physiological effect through high-affinity binding to specific membrane receptors. On studying further the molecular properties of the ANF receptor binding domain, we have observed that incubation of intact or solubilized bovine adrenal zona glomerulosa membranes with 125I-ANF-(99-126) followed by u.v. irradiation results in the irreversible labelling of a 130 kDa protein corresponding to the ANF-RI receptor. This process is time-, protein- and 125I-ANF-dependent. The apparently covalent nature of this complex is documented by its resistance to heat, guanidine hydrochloride, urea and trichloroacetic acid denaturation. Photolabelling with underivatized 125I-ANF is much more efficient with the ANF-R1 than with the ANF-R2 receptor. After photolysis, the covalently linked 125I-ANF is still sensitive to digestion by carboxypeptidase A, suggesting that ANF is linked by its N-terminal end to the receptor upon u.v. irradiation and that its C-terminal end is still freely accessible. Aerobic conditions and lipids are required for the photolabelling, suggesting a role in this process for malondialdehyde, a highly reactive secondary product associated with u.v.-induced lipid peroxidation. This simple method should provide a powerful tool in the accurate characterization of the hormone-binding domain of the ANF receptor.

Further investigations on the Atrial Natriuretic Factor (ANF)-induced inhibition of the growth and steroidogenic capacity of rat adrenal zona glomerulosa in vivo

1988 ◽  
Vol 29 (6) ◽  
pp. 605-609 ◽  
Author(s):  
Piera Rebuffat ◽  
Giuseppina Mazzocchi ◽  
Gluseppe Gottardo ◽  
Virgilio Meneghelli ◽  
Gastone G. Nussdorfer
Keyword(s):  
Atrial Natriuretic Factor ◽  
Zona Glomerulosa ◽  
Natriuretic Factor ◽  
Atrial Natriuretic

Atrial natriuretic factor binding sites in experimental congestive heart failure

1989 ◽  
Vol 257 (4) ◽  
pp. F515-F523
Author(s):  
C. Bianchi ◽  
G. Thibault ◽  
E. Wrobel-Konrad ◽  
A. De Lean ◽  
J. Genest ◽  
...  
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Binding Sites ◽  
Atrial Natriuretic Factor ◽  
Severe Heart Failure ◽  
Zona Glomerulosa ◽  
Renal Glomeruli ◽  
Natriuretic Factor ◽  
Cardiomyopathic Hamsters ◽  
Atrial Natriuretic

A quantitative in vitro autoradiographic study was performed on the aorta, renal glomeruli, and adrenal cortex of cardiomyopathic hamsters in various stages of heart failure and correlated, in some instances, with in vivo autoradiography. The results indicate virtually no correlation between the degree of congestive heart failure and the density of 125I-labeled atrial natriuretic factor [(Ser99, Tyr126)ANF] binding sites (Bmax) in the tissues examined. Whereas the Bmax was increased in the thoracic aorta in moderate and severe heart failure, there were no significant changes in the zona glomerulosa. The renal glomeruli Bmax was lower in mild and moderate heart failure compared with control and severe heart failure. The proportion of ANF B- and C-receptors was also evaluated in sections of the aorta, adrenal, and kidney of control and cardiomyopathic hamsters with severe heart failure. (Arg102, Cys121)ANF [des-(Gln113, Ser114, Gly115, Leu116, Gly117) NH2] (C-ANF) at 10(-6) M displaced approximately 505 of (Ser99, Tyr126)125I-ANF bound in the aorta and renal glomeruli and approximately 20% in the adrenal zona glomerulosa in both series of animals. These results suggest that ANF may exert a buffering effect on the vasoconstriction of heart failure and to a certain extent may inhibit aldosterone secretion. The impairment of renal sodium excretion does not appear to be related to glomerular ANF binding sites at any stage of the disease.

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