Digoxin radioimmunoassay: A comparison of the assay performances using tritiated and 125I radioiodinated tracers

Barbieri, U; Gandolfi, C.

doi:10.1016/0009-8981(77)90228-5

Cited by 12 publications

(5 citation statements)

References 8 publications

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“…0.05 mg/L (6.4 × 10 -8 M). The value is higher than the limits of detection in other digoxin assays. 23e-g The concentration range of digoxin that can be measured is between ca. 0.05 and 20 mg/L (6.4 × 10 -8 and 2.6 × 10 -5 M).…”

Section: Resultsmentioning

confidence: 86%

“…Digoxin is a widely used cardiac glycoside for control of congestive heart failure and various disturbances of cardiac rhythm . Homogeneous and heterogeneous immunoassays for digoxin have been developed to monitor the level of the drug in the sera. The design of heterogeneous immunoassays has relied on different tracers, including radionuclide-, 23a,b enzyme-, 23c,d chemiluminescence-,23d and lanthanide-based reagents. 23e,f In addition, the use of ruthenium(II) diimine complexes as electrochemiluminescent labels in the development of digoxin immunoassays has also been investigated 23g.…”

Section: Resultsmentioning

confidence: 99%

“…Homogeneous and heterogeneous immunoassays for digoxin have been developed to monitor the level of the drug in the sera. The design of heterogeneous immunoassays has relied on different tracers, including radionuclide-, 23a,b enzyme-, 23c,d chemiluminescence-,23d and lanthanide-based reagents. 23e,f In addition, the use of ruthenium(II) diimine complexes as electrochemiluminescent labels in the development of digoxin immunoassays has also been investigated 23g. In the present work, a heterogeneous immunoassay for digoxin using digoxin-coated microspheres, a biotinylated monoclonal anti-digoxin, and the luminescent conjugate [Ir(pq) 2 (phen-ITC)](PF) 6 -Av is studied.…”

Section: Resultsmentioning

confidence: 99%

“…First, the amount of digoxin-BSA conjugate immobilized on the microspheres is investigated. Increasing the amount of digoxin-BSA coating promotes nonspecific binding of the luminescent avidin conjugate to the solid phase 23f. Although this nonspecific binding should be minimized, the amount of coated digoxin must be sufficient for the recognition by the biotinylated antibody (and then by the luminescent tracer molecules).…”

Section: Resultsmentioning

confidence: 99%

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New Luminescent Cyclometalated Iridium(III) Diimine Complexes as Biological Labeling Reagents

et al. 2003

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We report the synthesis, characterization, and photophysical and electrochemical properties of thirty luminescent cyclometalated iridium(III) diimine complexes [Ir(N-C)(2)(N-N)](PF(6)) (HN-C = 2-phenylpyridine, Hppy; 2-(4-methylphenyl)pyridine, Hmppy; 3-methyl-1-phenylpyrazole, Hmppz; 7,8-benzoquinoline, Hbzq; 2-phenylquinoline, Hpq; N-N = 4-amino-2,2'-bipyridine, bpy-NH(2); 4-isothiocyanato-2,2'-bipyridine, bpy-ITC; 4-iodoacetamido-2,2'-bipyridine, bpy-IAA; 5-amino-1,10-phenanthroline, phen-NH(2); 5-isothiocyanato-1,10-phenanthroline, phen-ITC; 5-iodoacetamido-1,10-phenanthroline, phen-IAA). The X-ray crystal structure of [Ir(mppz)(2)(bpy-NH(2))](PF(6)) has also been investigated. Upon irradiation, all the complexes display intense and long-lived luminescence under ambient conditions and in 77-K glass. On the basis of the photophysical and electrochemical data, the emission of most of these complexes is assigned to an excited state of predominantly triplet metal-to-ligand charge-transfer ((3)MLCT) (dpi(Ir) --> pi(N-N)) character. In some cases, triplet intraligand ((3)IL) (pi --> pi)(N-N or N-C(-)) excited states have also been identified. In view of the specific reactivity of the isothiocyanate and iodoacetamide moieties toward the primary amine and sulfhydryl groups, respectively, we have labeled various biological molecules with a selection of these luminescent iridium(III) complexes. The photophysical properties of the luminescent conjugates have been investigated. In addition, a heterogeneous assay for digoxin has also been designed on the basis of the recognition of biotinylated anti-digoxin by avidin labeled with one of the luminescent iridium(III) complexes.

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Section: Resultsmentioning

confidence: 86%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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New Luminescent Cyclometalated Iridium(III) Diimine Complexes as Biological Labeling Reagents

et al. 2003

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“…[6][7][8] In the radioimmunoassay (RIA) for determining digoxin concentrations in serum, 3 H-and 125 I-labeled digoxin derivatives have been widely used. [8][9][10] We recently reported the preparation and antigenic properties of digoxin-bovine serum albumin (BSA) conjugates linked at the digitoxose C-3Ј and C-3Љ positions. 11,12) The properties of the antisera were characterized by RIA for [ 3 H]-digoxin.…”

mentioning

confidence: 99%

Development of Radioimmunoassay for Measurement of Serum Digoxin in Digitalized Patients Using Novel Anti-digoxin Antiserum.

Ikeda

Araki

Takimoto

et al. 2002

Biological & Pharmaceutical Bulletin

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Digoxin is the most widely used cardiac glycoside for the treatment of congestive heart failure and atrial fibrillation. Digoxin is known to be converted metabolically to digoxigenin bis-digitoxoside, digoxigenin mono-digitoxoside and digoxigenin by cleavage of the sugar moiety. 1,2) In addition, it is metabolized to dihydrodigoxin by reduction of the double bond in the lactone ring.3)The analysis of digoxin in biological fluids can be performed by immunoassays. The antisera used for these immunoassays are produced by immunization with a haptencarrier protein conjugate, which is coupled to the terminal digitoxose of digoxin using periodate oxidation. 4,5) These antisera show high cross-reactivity with metabolites formed by the successive cleavage of the digitoxose residues. [6][7][8] In the radioimmunoassay (RIA) for determining digoxin concentrations in serum, 3 H-and 125 I-labeled digoxin derivatives have been widely used. [8][9][10] We recently reported the preparation and antigenic properties of digoxin-bovine serum albumin (BSA) conjugates linked at the digitoxose C-3Ј and C-3Љ positions. 11,12) The properties of the antisera were characterized by RIA for [ 3 H]-digoxin. Although the antiserum elicited by digoxin 3Ј-hemisuccinate-BSA conjugate possesses high specificity for digoxin, it still lacks the sensitivity needed for measurement of digoxin concentrations in serum. The sensitivity of RIA increases using a tracer whose specific radioactivity is high. In the present study, we describe development of a type of RIA of digoxin 3Ј-hemisuccinyl-[ 3 H]leucine using the antiserum elicited by digoxin 3Ј-hemisuccinate-BSA conjugate for measuring digoxin in serum from digitalized patients, and compare its performance with commercially available anti-digoxin BSA serum and monoclonal anti-digoxin. , and Dextran T-70 from Pharmacia Fine Chemicals (Uppsala, Sweden). Norit SX and other general reagents were supplied by Wako Pure Chemical Industries (Osaka, Japan). Digoxigenin, and its mono-and bis-digitoxosides were prepared by hydrolysis of digoxin according to the methods of Kaiser and his colleagues. MATERIALS AND METHODS Materials 13)RIA was performed in phosphate saline buffer (pH 7.4) containing K 2 HPO 4 (0.696 g), NaH 2 PO 4 · H 2 O (0.138 g), NaCl (4.39 g), and BSA (1.0 g) in H 2 O (500 ml). A dextrancoated charcoal suspension was prepared by continuously stirring Norit SX (500 mg) and Dextran T-70 (50 mg) in cold phosphate saline buffer (40 ml) for 10 min prior to use.The antiserum (antibody (A)) was prepared by immunizing rabbit with digoxin 3Ј-hemisuccinate-BSA conjugate. 12)The commercial anti-digoxin BSA serum (antibody (B)) and monoclonal anti-digoxin (antibody (C)) were supplied by BioMakor Co. (Rehovot, Israel).Apparatus The melting point was determined with a Yanagimoto micro hot-stage apparatus and is uncorrected. Optical rotation was measured with a JASCO DIP-370 digital polarimeter. FAB-MS measurement was made on a JEOL HX-100 instrument equipped with a FAB ion source using glycerol and NaCl as th...

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Digoxin Serum Levels

Taylor¹

1978

JAMA

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Digoxin radioimmunoassay: A comparison of the assay performances using tritiated and 125I radioiodinated tracers

Cited by 12 publications

References 8 publications

New Luminescent Cyclometalated Iridium(III) Diimine Complexes as Biological Labeling Reagents

New Luminescent Cyclometalated Iridium(III) Diimine Complexes as Biological Labeling Reagents

Development of Radioimmunoassay for Measurement of Serum Digoxin in Digitalized Patients Using Novel Anti-digoxin Antiserum.

Digoxin Serum Levels

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