title: Development of glycoside-bound radiopharmaceuticals: novel radioiodination method for digoxin.
abstract: We combined 2-hydroxy-3-methylbenzoylhydrazide (HMBH) with glycosides as a novel method for the radioiodination of physiologically active glycosides. This method was tested using digoxin, which is one of the cardiac glycosides. A digoxin-HMBH conjugate was synthesized by periodate cleavage of the third sugar ring, and was readily radiolabeled with Na[125I] by the chloramine-T method. 125I labelled digoxin-HMBH conjugate retained Na+, K(+)-ATPase binding in vivo and in vitro, and also retained immunoreactivity to an anti-digoxin antibody. Thus, this 125I labelled digoxin-HMBH conjugate represents a potential radiopharmaceutical for Na+, K(+)-ATPase imaging, as well as for the radioimmunoassay of digoxin.
authors.affiliation: Department of Radiopharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Kyoto University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Takemura
authors.forename: Y
authors.initials: Y
authors.lastname: Fujibayashi
authors.forename: N
authors.initials: N
authors.lastname: Dote
authors.forename: H
authors.initials: H
authors.lastname: Taniuchi
authors.forename: N
authors.initials: N
authors.lastname: Iijima
authors.forename: J
authors.initials: J
authors.lastname: Konishi
authors.forename: A
authors.initials: A
authors.lastname: Yokoyama
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D002700:Chloramines / Q000737:chemistry; D004077:Digoxin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics; D006168:Guinea Pigs; D007457:Iodine Radioisotopes; D007553:Isotope Labeling; D009206:Myocardium / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology; D011863:Radioimmunoassay; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
chemical_list: D002700:Chloramines; D007457:Iodine Radioisotopes; C086700:digoxin-di-(2-hydroxy-3-methylbenzoylhydrazide) conjugate; D010042:Ouabain; D004077:Digoxin; D000254:Sodium-Potassium-Exchanging ATPase; C030816:chloramine