Preparation of mono-radioiodinated tracers for study of the in vivo metabolism of atrial natriuretic peptide in humans

Clerico, Aldo; Iervasi, Giorgio; Manfredi, C.; Salvadori, Severo; Marastoni, Mauro; Chicca, M.G. Del; Giannessi, Daniela; Ry, Silvia Del; Andreassi, Maria Grazia; Sabatinor, Laura; Iascone, Maria; Biaginir, Andrea; Donator, Luigi

doi:10.1007/bf00808410

Cited by 14 publications

(8 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, we found superimposable labeled ANP steady state concentration values in the pulmonary artery (input of lungs) and aorta (output of lungs) during constant infusion of tracer in the right atrium, and superimposable AUC values of labeled ANP in the aorta and in pulmonary artery after bolus injection of tracer, indicating that tracer that enters lungs through the pulmonary artery is completely recovered in the aorta. It is also evident from all the present studies that 125 I-labeled ANP is extracted in vivo by peripheral organs, in agreement with previous data (1,14,20). This last observation gives further support to the hypothesis that labeled ANP shares similar biological activity with native hormone, as already reported by two studies demonstrating that labeled ANP is able to interact with specific receptors and can be degraded by specific enzymes in a similar manner to the native hormone (1,21).…”

Section: Discussionsupporting

confidence: 94%

“…Synthetic ␣h 1-28 ANP was iodinated with Na 125 I or Na 131 I as previously described in detail elsewhere (14,20). A drop of the injected tracer that remained in the syringe after the injection was collected and tested for purity by high performance liquid chromatography; in all kinetic studies, less than 1% impurity was found.…”

Section: Experimental Protocolmentioning

confidence: 99%

“…All blood samples were collected in ice-chilled disposable polypropylene tubes, containing aprotinin (500 KIU/mL of plasma) and EDTA (1 mg/mL of plasma); plasma samples were immediately separated by centrifugation, and then frozen and stored in various aliquots at Ϫ20 C, and finally assayed with the IRMA (20).…”

Section: Anp Assaymentioning

confidence: 99%

“…The blood samples collected were immediately put into ice-chilled disposable polypropylene tubes, containing aprotinin (500 kallikrein inhibiting units (KIU)/mL of plasma) and EDTA (1 mg/mL of plasma), and the plasma was rapidly separated in a refrigerated centrifuge at 4 C. All experimental blood samples were extracted with Bond Elut C18 cartridges (Analytical International, Harbor City, CA) and then purified by means of an high performance liquid chromatography procedure as previously described in detail (14,20).…”

Section: Experimental Protocolmentioning

confidence: 99%

See 3 more Smart Citations

Atrial Natriuretic Peptide Is Not Degraded by the Lungs in Humans

Iervasi

Clerico

Pilo

et al. 1998

The Journal of Clinical Endocrinology &Amp; Metabolism

Self Cite

View full text Add to dashboard Cite

In an attempt to identify and quantify the sites of atrial natriuretic peptide (ANP) degradation, particularly the lungs, a new tracer method to study ANP metabolism in vivo in humans was developed and applied to patients with left ventricular dysfunction. Thirteen male, normotensive, cardiac patients with different degrees of left ventricular myocardial involvement were enrolled in the study. The study protocol required constant infusion (3 patients) or bolus injection (10 patients) of 125I-labeled ANP just upstream of the right atrium and blood sampling from different sites (pulmonary artery, aorta, inferior vena cava, and femoral vein) during the hemodynamic study. Data analysis was based on a kinetic model consisting of three blocks in series (right heart, lungs and left heart, and periphery) supplied by the same plasma flow (plasma cardiac output). Plasma levels of native ANP were measured with a sensitive and specific immunoradiometric assay method. ANP values measured in the aorta (163.9 +/- 144.8 pg/mL, n = 80) were superimposable on those measured in the pulmonary artery (161.8 +/- 136.5 pg/mL, n = 80). Negligible extraction of 125I-labeled ANP was found in the lungs and left heart block (on average 0.08 +/- 3.92%), whereas the peripheral block extraction (46.2 +/- 7.8%) accounted for almost total hormone removal from the blood (whole body extraction was 46.4 +/- 6.6%). ANP metabolic clearance rate (3.11 +/- 1.48, range 1.4-6.8 L/min) declined with the progression of left ventricular dysfunction (plasma cardiac output 3.46 +/- 1.08, range 1.2-5.7 L/min), and a close correlation between metabolic clearance rate and cardiac output was evident. Our data suggest that lungs do not extract, or extract only very small amounts, of labeled ANP administered iv to patients with different degrees of left ventricular myocardial involvement, and whole body extraction of labeled ANP remains relatively stable with the progression of disease, and the large reductions in clearance values observed in our patients can be ascribed mainly to the reductions in cardiac output.

show abstract

Section: Discussionsupporting

confidence: 94%

Section: Experimental Protocolmentioning

confidence: 99%

Section: Anp Assaymentioning

confidence: 99%

Section: Experimental Protocolmentioning

confidence: 99%

See 2 more Smart Citations

Atrial Natriuretic Peptide Is Not Degraded by the Lungs in Humans

Iervasi

Clerico

Pilo

et al. 1998

The Journal of Clinical Endocrinology &Amp; Metabolism

Self Cite

View full text Add to dashboard Cite

show abstract

“…Earlier studies were limited by poor assay sensitivity and specificity, cross-reactivity with other plasma proteins, and gross interassay variability. The earlier immunoassays also could not reliably define concentration ranges in normal individuals (141)(142)(143)(144)(145)(146)(147)(148). Furthermore, it is now known that there are numerous circulating peptide fragments of ANP, each with varying biologic activities (149).…”

Section: Natriuretic Peptides In Renal Diseasementioning

confidence: 99%

Natriuretic Peptides and the Dialysis Patient

Suresh

Farrington

2005

Seminars in Dialysis

View full text Add to dashboard Cite

The natriuretic peptide family consists of four structurally similar, but genetically distinct molecules with pronounced cardiovascular and renal actions. They are counterregulatory hormones playing an important role in fluid volume homeostasis. Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) cause diuresis, natriuresis, and vasodilatation. C-type natriuretic peptide (CNP) has antimitogenic effects and causes vascular smooth muscle relaxation. Dendroaspis natriuretic peptide (DNP) shares many of the actions of ANP and BNP, but its function in humans is not yet fully understood. Natriuretic peptides have been extensively investigated as biochemical markers of the fluid state. Levels are elevated in disease conditions characterized by fluid overload and are closely related to survival in various cardiac disease states. In the dialysis population, BNP correlates significantly with cardiac function, whereas ANP is sensitive to volume changes during dialysis. However, changes in concentration do not predict achievement of euvolemia, and short half-life, combined with complicated assay techniques, make ANP a less than satisfactory tool for assessing hydration. BNP is a superior prognosticator for risk stratification in dialysis patients, and serial estimations will help in the identification of occult cardiac disease.

show abstract

Cardiac Natriuretic Hormones as Markers of Cardiovascular Disease: Methodological Aspects

Panteghini

Clerico

Natriuretic Peptides

View full text Add to dashboard Cite

Preparation of mono-radioiodinated tracers for study of the in vivo metabolism of atrial natriuretic peptide in humans

Cited by 14 publications

References 8 publications

Atrial Natriuretic Peptide Is Not Degraded by the Lungs in Humans

Atrial Natriuretic Peptide Is Not Degraded by the Lungs in Humans

Natriuretic Peptides and the Dialysis Patient

Cardiac Natriuretic Hormones as Markers of Cardiovascular Disease: Methodological Aspects

Contact Info

Product

Resources

About