Localization of 125I-atrial natriuretic factor (ANF)-binding sites in rat renal medulla. A light and electron microscope autoradiographic study.

Using light and electron microscope autoradiography in vivo, the localization of 125I-(Arg 101-Tyr 126) atrial natriuretic factor (ANF)-binding sites was studied in the renal medulla of rats. At the light microscopic level, the autoradiographic reaction was mainly distributed in patches in the outer medulla, and followed the tubular architecture in the innermost part of the inner medulla. At the electron microscopic level, binding sites were mainly found in the outer medullary descending vasa recta and inner medullary collecting ducts. These results suggest that, in rats, the renal medulla may participate in the natriuresis and diuresis produced by ANF through vascular and tubular effects; the former by changing medullary blood flow at the level of descending vasa recta and the latter by acting on electrolyte and water transport at the level of collecting ducts.

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Autoradiographic localization of binding sites for atrial natriuretic factor

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y85-226 ◽

1985 ◽

Vol 63 (11) ◽

pp. 1373-1377 ◽

Cited By ~ 49

Author(s):

H. P. von Schroeder ◽

E. Nishimura ◽

C. H. S. McIntosh ◽

A. M. J. Buchan ◽

N. Wilson ◽

...

Keyword(s):

Binding Sites ◽

Atrial Natriuretic Factor ◽

Renal Medulla ◽

Rabbit Aorta ◽

Wistar Rat ◽

Iliac Vein ◽

Zona Glomerulosa ◽

Rat Tissues ◽

Natriuretic Factor ◽

Atrial Natriuretic

The distribution of atrial natriuretic factor (ANF) binding sites in Wistar rat tissues, as well as tissues from other species was studied. Using autoradiography of slide mounted tissue sections incubated with 125I-labelled ANF, high densities of binding sites were found in the renal glomeruli and papilla, aortic smooth muscle, iliac vein, choroid plexus, anterior pituitary, lung, and adrenal zona glomerulosa. Results from renal, aortic, adrenal, and lung tissues from spontaneously hypertensive rats did not differ from those of Wistar rats. Binding sites were also observed in guinea pig glomeruli, renal medulla, and aorta as well as in the rabbit aorta.

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Binding sites for atrial natriuretic factor (ANF) in kidneys and adrenal glands of spontaneously hypertensive (SHR) rats

Life Sciences ◽

10.1016/0024-3205(87)90016-6 ◽

1987 ◽

Vol 40 (17) ◽

pp. 1673-1681 ◽

Cited By ~ 24

Author(s):

Susan E. Swithers ◽

Robert E. Stewart ◽

Richard McCarty

Keyword(s):

Binding Sites ◽

Atrial Natriuretic Factor ◽

Adrenal Glands ◽

Shr Rats ◽

Spontaneously Hypertensive ◽

Natriuretic Factor ◽

Atrial Natriuretic

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Atrial natriuretic factor binding sites in the jejunum

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1989.256.2.g436 ◽

1989 ◽

Vol 256 (2) ◽

pp. G436-G441 ◽

Cited By ~ 1

Author(s):

C. Bianchi ◽

G. Thibault ◽

A. De Lean ◽

J. Genest ◽

M. Cantin

Keyword(s):

Binding Sites ◽

Atrial Natriuretic Factor ◽

Specific Binding ◽

Rat Tissues ◽

Rat Jejunum ◽

Specific Binding Sites ◽

Natriuretic Factor ◽

Atrial Natriuretic

We have studied the localization and the characterization of atrial natriuretic factor (ANF) binding sites by radioautographic techniques. Quantitative in vitro radioautography with a computerized microdensitometer demonstrated the presence of high-affinity, low-capacity 125I-ANF-(99-126) binding sites (Kd, 48 pM; Bmax, 63 fmol/mg protein) mainly in the villi of 20-microns slide-mounted transverse sections of the rat jejunum. Competition curves showed 50% inhibitory concentrations of 55 and 1,560 pM for ANF-(99-126) and ANF-(103-123), respectively. In vivo electron microscope radioautography showed that 80% of the silver grains were localized on the lamina propria fibroblast-like cells, 18% on mature enterocytes, and 2% on capillaries. Bradykinin and adrenocorticotropin did not compete with ANF binding. These results demonstrate that ANF binding sites in the rat jejunum possess the pharmacological characteristics of functional ANF receptors encountered in other rat tissues, and ultrastructural radioautographs show their cellular distribution. Taken together, these results demonstrate the presence and the localization of specific binding sites for ANF in the jejunal villi of the rat small intestine.

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Distinct localization of atrial natriuretic factor and angiotensin II binding sites in the glomerulus

AJP Renal Physiology ◽

10.1152/ajprenal.1986.251.4.f594 ◽

1986 ◽

Vol 251 (4) ◽

pp. F594-F602 ◽

Cited By ~ 2

Author(s):

C. Bianchi ◽

J. Gutkowska ◽

G. Thibault ◽

R. Garcia ◽

J. Genest ◽

...

Keyword(s):

Angiotensin Ii ◽

Comparative Study ◽

Binding Sites ◽

Atrial Natriuretic Factor ◽

Mesangial Cells ◽

Ang Ii ◽

Half Maximum ◽

Natriuretic Factor ◽

Glomerular Size ◽

Atrial Natriuretic

A comparative study of the localization of 125I-labeled atrial natriuretic factor (ANF) and 125I-labeled angiotensin II (ANG II) binding sites in the glomerulus of the rat, after an intravascular injection, has been done by ultrastructural radioautography. 125I-ANF binding sites are localized predominantly on the podocytes of the visceral epithelium (63%) followed by the endothelium of capillaries (14%), the parietal epithelium (13%), and finally mesangial cells (10%). In a comparative study, it was confirmed that 125I-ANG II uptake is localized predominantly on mesangial cells (60%) followed by epithelial visceral cells (23%) and the endothelium of capillaries (16%). Using isolated rat glomeruli, it was confirmed that ANG II decreases glomerular size (maximum effect of 15%) with an apparent half maximum effective concentration (EC50) between 10(-9) and 10(-8) M. Although ANF alone has no apparent effect on glomerular size, it inhibits the contractile effect of ANG II with a half maximum inhibitory concentration (IC50) between 10(-11) and 10(-10) M. These results suggest that an intraglomerular mechanism other than glomerular arteriolar resistance may be involved in the modulation of glomerular filtration rate by ANF. The presence of 125I-ANF uptake mainly in foot processes of visceral epithelial cells of glomeruli in vivo and the inhibition of ANG II decrease in glomerular size by ANF in vitro raise the possibility that ANF may regulate the ultrafiltration coefficient by two mechanisms: modulation of glomerular permeability, and surface area.

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