Segregation of atrial-specific and inducible expression of an atrial natriuretic factor transgene in an in vivo murine model of cardiac hypertrophy

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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In vitro secretion of atrial natriuretic factor: receptor-mediated release of prohormone

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1988.254.5.r809 ◽

1988 ◽

Vol 254 (5) ◽

pp. R809-R814 ◽

Cited By ~ 2

Author(s):

A. T. Veress ◽

S. Milojevic ◽

C. Yip ◽

T. G. Flynn ◽

H. Sonnenberg

Keyword(s):

Atrial Natriuretic Factor ◽

Active Form ◽

High Concentration ◽

Natriuretic Factor ◽

Rat Hearts ◽

Agonist Concentration ◽

Atrial Natriuretic Factor Receptor ◽

Atrial Natriuretic

Secretion of atrial natriuretic factor (ANF) in vivo is thought to be mediated by atrial distension. We have shown previously that nonstretched atria can release natriuretic activity in vitro when stimulated by certain agonists. In the present study atrial appendages from freshly excised rat hearts were incubated at 37 degrees C for up to 1 h in the presence of either vasopressin (5 X 10(-9) mol/l) or angiotensin II (2.5 X 10(-7) mol/l). Aliquots of postincubation media were injected intravenously into anesthetized bioassay rats to determine natriuretic activity. Control media, in which atria had been incubated without agonist, did not cause natriuresis. Significant increases in sodium excretion were seen after injection of media in which atria had been incubated in the presence of either agonist. Injection of medium with the same agonist concentration did not result in comparable natriuresis. Radioimmunoassay (RIA) indicated a high concentration of immunoactive ANF in the natriuretic media. However, radioreceptor assay (RRA) of the same media gave apparent ANF concentrations that were lower by about three orders of magnitude. Because the antibody used in the RIA cross reacts with ANF prohormone, whereas the RRA is sensitive only to the active form, we concluded that agonist-induced, stretch-independent release of ANF is in the form of prohormone, which can be converted to the active hormone in the circulation of the bioassay animal. The conclusion of prohormone release was confirmed by liquid chromatography. The data thus suggest that receptor-mediated as well as stretch-induced ANF secretion may be important in regulating the activity of the ANF system.

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Effect of atrial natriuretic factor on the plasma aldosterone response to potassium infusion in rats - in vivo study

Life Sciences ◽

10.1016/0024-3205(86)90654-5 ◽

1986 ◽

Vol 39 (4) ◽

pp. 359-364 ◽

Cited By ~ 17

Author(s):

Masao Takagi ◽

Roberto Franco-Saenz ◽

Patrick J. Mulrow

Keyword(s):

Atrial Natriuretic Factor ◽

Plasma Aldosterone ◽

In Vivo Study ◽

Natriuretic Factor ◽

Atrial Natriuretic

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Degradation of atrial natriuretic factor in the rat

Biochemical Journal ◽

10.1042/bj2400461 ◽

1986 ◽

Vol 240 (2) ◽

pp. 461-469 ◽

Cited By ~ 48

Author(s):

K K Murthy ◽

G Thibault ◽

R Garcia ◽

J Gutkowska ◽

J Genest ◽

...

Keyword(s):

Whole Blood ◽

Atrial Natriuretic Factor ◽

Mesenteric Artery ◽

Biologically Active ◽

Prolonged Incubation ◽

Amino Acid Peptide ◽

Natriuretic Factor ◽

Atrial Natriuretic

The biologically active circulating form of atrial natriuretic factor (ANF) in the rat is the 28-amino-acid peptide ANF-(Ser-99-Tyr-126). Degradation of this peptide in vivo as well as in vitro, in whole blood, in plasma and by the isolated mesenteric artery was investigated. Studies in vivo in the rat demonstrated that the elimination and degradation of ANF was extremely fast: within 3 min more than 95% of the injected immunoreactive material was eliminated from circulation. The production of a short C-terminal peptide was detected on injection of 125I-ANF-(Ser-99-Tyr-126) into the rat. This peptide increased proportionately with incubation time. Experiments in vitro in the presence of whole blood or plasma did not cause any major destruction of ANF even after incubation for 60 min. After this prolonged incubation in plasma, ANF-(Ser-99-Tyr-126) was partially converted into ANF-(Ser-103-Tyr-126), a less potent peptide. Isolated mesenteric-artery preparation appeared to degrade ANF in a manner very similar to the system in vivo. These results suggest that degradation of ANF may occur either after internalization in the vascular cells or by a membrane-bound enzyme in the vasculature.

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Clearance and early hydrolysis of atrial natriuretic factor in vivo. Structural analysis of cleavage sites and design of an analogue that inhibits hormone cleavage.

Journal of Clinical Investigation ◽

10.1172/jci113462 ◽

1988 ◽

Vol 81 (5) ◽

pp. 1348-1354 ◽

Cited By ~ 27

Author(s):

C L Condra ◽

E A Leidy ◽

P Bunting ◽

C D Colton ◽

R F Nutt ◽

...

Keyword(s):

Structural Analysis ◽

Atrial Natriuretic Factor ◽

Cleavage Sites ◽

Natriuretic Factor ◽

Hydrolysis Of ◽

Atrial Natriuretic

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Biochemical mechanisms of atrial natriuretic factor action

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y89-179 ◽

1989 ◽

Vol 67 (9) ◽

pp. 1124-1129 ◽

Cited By ~ 5

Author(s):

Johanne Tremblay ◽

Pavel Hamet

Keyword(s):

Heart Failure ◽

Guanylate Cyclase ◽

Atrial Natriuretic Factor ◽

Soluble Guanylate Cyclase ◽

Membrane Glycoprotein ◽

Natriuretic Factor ◽

Biochemical Mechanisms ◽

Stimulation Of ◽

Atrial Natriuretic

Since atrial natriuretic factor (ANF) is a natriuretic and vasodilatory hormone, its mechanisms of action expectedly involve so-called negative pathways of cell stimulation, notably cyclic nucleotides. Indeed, the guanylate cyclase–cyclic GMP (cGMP) system appears to be the principal mediator of ANF's action. Specifically, particulate guanylate cyclase, a membrane glycoprotein, transmits ANF's effects, as opposed to the activation of soluble guanylate cyclase by such agents as sodium nitroprusside. The stimulation of particulate guanylate cyclase by ANF manifests several characteristics. One of them is the functional irreversibility of stimulation with its apparent physiological consequences: the extended impact of ANF on diuresis and vasodilation in vivo lasts beyond the duration of increased plasma ANF levels and is accompanied by a prolonged elevation of cGMP. Another characteristic is the parallelism between guanylate cyclase stimulation and increases of cGMP in extracellular fluids. cGMP egression appears to be an active process, yet its physiological implications remain to be uncovered. In heart failure, cGMP continues to reflect augmented ANF levels, suggesting that in this disease, the lack of an ANF effect on sodium excretion is due to a defect distal to cGMP generation. In hypertension, where ANF levels are either normal or slightly elevated, probably secondary to high blood pressure, the ANF responsiveness of the particulate guanylate cyclase–cGMP system, the hypotensive effects, diuresis and natriuresis are exaggerated. The implications of this exaggerated responsiveness of the ANF–cGMP system in the pathophysiology of hypertension and its potential therapeutic connotations remain to be evaluated.Key words: ANF, cGMP, guanylate cyclase, hypertension, heart failure.

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Atrial natriuretic factor influences in vivo plasma, lung and aortic wall cGMP concentrations differently

European Journal of Pharmacology ◽

10.1016/0014-2999(93)90278-p ◽

1993 ◽

Vol 237 (2-3) ◽

pp. 265-273 ◽

Cited By ~ 15

Author(s):

Jean-François Arnal ◽

Abdel-Ilah El Amrani ◽

Jean-Baptiste Michel

Keyword(s):

Atrial Natriuretic Factor ◽

Aortic Wall ◽

Natriuretic Factor ◽

Atrial Natriuretic

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Atrial natriuretic factor stimulates exocrine pancreatic secretion in the rat through NPR-C receptors

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00010.2003 ◽

2003 ◽

Vol 285 (5) ◽

pp. G929-G937 ◽

Cited By ~ 30

Author(s):

María E. Sabbatini ◽

Alberto Villagra ◽

Carlos A. Davio ◽

Marcelo S. Vatta ◽

Belisario E. Fernández ◽

...

Keyword(s):

Nitric Oxide ◽

Pancreatic Secretion ◽

Intracellular Signaling ◽

Atrial Natriuretic Factor ◽

Adrenergic Blockade ◽

Exocrine Pancreatic Secretion ◽

Pancreatic Acini ◽

Natriuretic Factor ◽

Atrial Natriuretic

Increasing evidence supports the role of atrial natriuretic factor (ANF) in the modulation of gastrointestinal physiology. The effect of ANF on exocrine pancreatic secretion and the possible receptors and pathways involved were studied in vivo. Anesthetized rats were prepared with pancreatic duct cannulation, pyloric ligation, and bile diversion into the duodenum. ANF dose-dependently increased pancreatic secretion of fluid and proteins and enhanced secretin and CCK-evoked response. ANF decreased chloride secretion and increased the pH of the pancreatic juice. Neither cholinergic nor adrenergic blockade affected ANF-stimulated pancreatic secretion. Furthermore, ANF response was not mediated by the release of nitric oxide. ANF-evoked protein secretion was not inhibited by truncal vagotomy, atropine, or Nω-nitro-l-arginine methyl ester administration. The selective natriuretic peptide receptor-C (NPR-C) receptor agonist cANP-(4–23) mimicked ANF response in a dose-dependent fashion. When the intracellular signaling coupled to NPR-C receptors was investigated in isolated pancreatic acini, results showed that ANF did not modify basal or forskolin-evoked cAMP formation, but it dose-dependently enhanced phosphoinositide hydrolysis, which was blocked by the selective PLC inhibitor U-73122. ANF stimulated exocrine pancreatic secretion in the rat, and its effect was not mediated by nitric oxide or parasympathetic or sympathetic activity. Furthermore, CCK and secretin appear not to be involved in ANF response. Present findings support that ANF exerts a stimulatory effect on pancreatic exocrine secretion mediated by NPR-C receptors coupled to the phosphoinositide pathway.

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